Before you post a question. Please take a moment to look through the comments because there is a very good chance it has been answered. Keep shreddy!!!
I’ll start off on a positive note here and say, that it is great to have a different approach and to question everything that we are told. However, I have two main problems, and dare I say concerns, with Lee’s advice. First, Lee presents his information, for my liking at the very least, with too much certainty and conviction. As if his “R.A.D” is singularly the only correct way to size a bike. The way he speaks leaves no room for nuance, compromise or rider preference. It is a “I am right, you are wrong attitude.” The world is many shades of grey. R.A.D. appears to be based off of one premise, the idea of a rider maximising their torque, which in itself, is a valid idea. This brings me to my second problem with this advice. The idea of maximising, or even utilising this idea of maximum torque excludes many, if not most other areas of the trail - how often do you ride your local trails trying to bunny hop as high as possible over every obstacle? Not many riders - actually none - that I see, and certainly not me. If this is you though, then potentially the R.A.D. measurement is for you. I would argue that this sizing idea, which, let’s be honest is to go shorter, ignores the many benefits of modern longer bike geometry which can not only increase rider confidence but potentially their safety. I would argue that So many manufacturers can’t be wrong. I’m sorry, but at the end of the day, I completely disagree with this advice for general, aggressive trail riding. But if you want to win a bunny hop competition then... thoughts @joy of bike?
@@thegriff9425 - hahaha, that's funny! I hope you are a grown up man, that can do your own filtering ;-) When that is said, I can't think of two more opposite movements than bunnyjumps and pedaling up a hill. And if this way of measuring take both of this positions into account, then I guess it could be pretty accurate. Both me and a friend did the measurement, and afterwards checked our bikes. We both have bikes that feels perfect, and both this bikes did match our RAD. We also both have bikes that we had a suspicion being too big, which this measurement did actually show. If I will trust this 100% next time, buying a bike, I don't know. But it did tell me that my latest bike is to big, which I for sure can feel. And that bike was bought after using the bike company's own sizing app.
Eh, I like your videos but I'm not sold on this or your other fit video. If you have two people that are exactly the same height, one with long arms and the other with short arms, according to this technique the person with long arms will require a smaller bike and the person with short arms will require a larger bike...
@@thegriff9425 But wouldn't having access to more torque help with many aspects of aggressive trail riding besides bunny hops? It will definitely help with pumping, and pumping is a technique undergirding jumping, as well as simple things like picking up speed on the trail. All of which is definitely part of "general, agressive trail riding." So that suggests that maximizing torque by having the right R.A.D. will actually help with trail riding. Also, I am not sure that "modern longer bike geometry" has to be sacrificed in order for RAD to apply. Doesn't the stability of "longer" bikes have more to do with a longer wheelbase (hence the steep head tube angle) than a different RAD? Seat tube angle + head tube angle can be adjusted so that RAD is the same or smaller even on a "longer" bike.
@@thegriff9425 from watching this and their other videos I believe the premise is that an optimal fit based on RAD is primarily to reduce injury. Rider comfort and optimizing power (torque) are merely beneficial effects of RAD.
At 180 cm I was riding 481 reach for a short period. 100÷ my experience. Settled at 465-470. Shorter feels even better most of the time, but I find that sometimes I have to move too much (hard braking after a drop is the best example).
Namastoke! May I recommend making an addendum video where you fix different setups? Stem rise/length/angle/stack, consequences of having grips behind or too near steering axis. Sometimes the solution isn't as simple as a stem change in my experience!
After a clinic with Lee, I swear by this method. With hardly any bike inventory in Australia, knowing my RAD and the frame measurements accessed via Lee's book Dialed, I bought a bike sight unseen and it fits like magic
A good tip for accuracy, double your crank length and make two marks on the floor at that measurement, (175mm crank = 350mm) when you position your feet, put the ball of your foot by each mark. Having your feet too far apart or close together can change your height. I also found its easier to hold a tape measure or string, or even a handlebar to get my hands at the exact width. I know none of this is exact science but it helps to get consistent measurements. Ive been wondering if I should really be on a bigger frame but Rad pretty much confirms that what Ive felt for years is correct. I'm 6'2" and I like a 475 reach, Large on most frames while a lot of "fit guides" put me on an XL. Nice job guys
This ^^^^ i was so confused as the pevious height calculation method had my rad perfect even with a 70 mm stem length. Then when i used the string method i was about 70mm rad + but had forgotten to hold my hands at handlebar width which made all the difference.
I came here to point this out also. Handlebar width makes a difference. This method of fit definitely works though. All the bikes I own that I really like, are at my rad. Used this to get a new bike for my wife also that was previously uncomfortable on her bike.
I don't know if you will ever see this @JoyofBike but this video and the handlebar one completely changed my riding experience. I cannot thank you enough!
Measured my RAD number at 86cm and was very pleased to find out my Meta HT (size L) was 85cm. I remember I changed my order from Med to Large after I already paid, now I've got proof that was the right choice.
Bro how tall are you? I ordered an M but I am not sure because of the reach... reach is only 420. I am 176cm. My inseam is around 79 and my RAD is 80 if i am not wrong. Armlength like 60. 🤔🤯😅
Same reason I changed my order from XL to L after I payed for the bike. I'm spot on 85cm RAD. I'm also almost a "perfect" human sizewise, 189cm tall with 88cm inseam and apeindex of 1 (lol)
A UK series!! Yeah make it happen. Love this channel. Can’t put my finger on it but there’s something different and relatable about you guys. Always entertaining and informative.
So I had a buddy show me the last RAD video after riding a skills park one day. After stopping to think about how heavy handed I was on the down hills and how hard jumping along with other skills were for me I did the math. Turned out I’m an in between. Swapped from a XL to an L, and the large just fell right in place. Weather has kept me from riding, but I’m stoked to get it on the trail. P.S. I was already looking at new bikes! The video just saved me from buying another oversized bike.
I can't understand the thumbs down you got. Good info, it all makes sense. 👍Lee has his own thoughts about mountainbiking and isn't just copying what the majority is telling you about it.
After 7 years of riding and multiple bikes, I shortened the stem on my current bike to match the R.A.D. you suggested. All I can say is "WOW, what a difference!". The bike feels better than ever and I have noticeably more control. Even better is being able to take this to any bike. It 's a game changer. Much appreciation for sharing!
Mind blown. I just did this measurement and both my bikes with out me even taking that much thought i have set up the to my needed RAD. My hardtail is with a 50mm stem size medium and my full sus is with a 60mm stem size medium but with a head angle kit (making it slacker) intalled. 🤯 I set them up my self when i got them just by sitting in the bike and riding a few times made the changes and been happy first time now i have the proof. Another great video.
I just wanted to say thank you to you both. Once I was able to dial in my RAD, it was as if the clouds parted and light shined down. I had complete control of my bars with no weight in my hands and I was floating and flying with all my weight through my feet in the center of my bike. I controlled the bike and not the bike controlling me. It has opened up a whole new feeling to biking and it is spectacular.
This R.A.D concept is interesting. I appreciate the intent of getting a bike that allows the rider to be as dynamic as possible, but I can't help but thinking that this concept is going to result in people optimizing for one ride characteristic/criteria at the expense of others, rather than striking a balance between the wide range of desirable characteristics. The R.A.D on my enduro bike measures about 40-50mm longer than the recommendation, while my dirt jump hardtail is exactly the recommended R.A.D length. Having ridden the DJ bike a lot recently, I can definitely feel how that size maximizes my ability to ride dynamically (move my hips, generate power when hopping, manual, etc.). Maximizing this trait makes a lot of sense on a dirt jump/pumptrack bike. However, if we accept that a longer bike is more stable at speed, it seems worthwhile to compromise some of that dynamism created by the short reach/R.A.D for more stability in an enduro or DH application, where you're riding faster and over rougher terrain, doesn't it? There is only so much length you can add to a bike while keeping the same R.A.D (slackening the head angle, lengthening the chainstay, etc), and each of the changes will also have an impact on the handling characteristics. My sense is that I gain more stability by adding length than I give up in that dynamic ride quality the R.A.D seems to maximize. It takes a bit more effort to manual or pop my enduro bike, but that seems like a worthwhile trade off for the additional stability brought by the longer reach/R.A.D - any thoughts on that? I also wonder if targeting R.A.D without considering other aspects of the bike's geometry and components will result in sub-optimal performance. For example, you talk about shortening the stem and adding backsweep to the handle bars. While this will shorten the R.A.D, it can also dramatically reduce the amount of weight the rider has on the front wheel, which can really reduce front end traction, which is essential for confident cornering. Similarly, for shorter/medium sized riders, sizing down to achieve on optimal R.A.D might result in them riding bikes with significantly longer chainstays than reaches, which can lead to some strange handling characteristics. Would these riders be better suited to a bike with a longer R.A.D, but a more balanced bike, rather than optimizing their R.A.D at the expense of some other handling traits?
GREAT point & GREAT questions. imo changing the stem bars seat positioning is a great thing... but if you go to far it seems like one would have a the worse of both worlds. So, dropping down a frame size and minor tweaks to positioning is the way to go. YES: Speed is the trade off in my (limited, less learned) opinion. **The gnarlier it gets, the twistier is gets, the steeper it gets, the smaller I want my frame size** -- but I still want 29" wheels, not smaller, because of the gnarl .. BUT, the trade off is for speed on a longer wheel-base bike... which means you must, must, weight the front end more. So, you are on target in my opinion. Here is mine questions that pertain to your's: Question: **Isnt RAD sizing is FAR more important the heavier the bike is? and The longer the wheel-base is?*** I ask because the new high performance Electric mtn bikes are so freak'n heavy, and the wheel size so large, and the wheel base has gotten so long. The bike shops are pushing me to the largest frame size. Seems they don't like me on a 2021 (old school large) which is smaller than the newer year (2022) : they want me on the largest new school (2022) large. Anyway: I test rode 5 brands, and 3 sizes in the preferred brand, and the smallest one (RAD + per my string) was the only one I could wheelie. Longer stem on that same bike, per the shop's recommendation, and my ability to wheelie was GONE. So, rather than drop $11,000.00US on a bike I am unsure of: I ran out an bought a Craiglist special (Epic, carbon fiber, 26" wheels, non-electric dually) in a frame size using RAD+, and it feels really good. I have to watch my speed for corners, most likely because I'm still not used to the smaller size. What say you to my points? Any input?
great points to consider for the varying types of bikes and riding styles/levels. Definitely more info needed here to shore up some of these and test in real world applications.
Definitely one of my favorite channels on RUclips. I love the positive energy. I can't wait to check the fit of my bike. Thank you both for your time and positivity.
@@JoyOfBike - I measured and I have the same RAD as you. I have ordered a shorter stem to bring my current bike in line - Thanks for the justification to buy new parts :)
After watching the step stool video in the cold garage I was obsessed with having a set of stools to check my RAD! Having seen this video and realizing I can just lay on my back like you would to practice tuck no handers and bar spins was such a good moment! Time to find out if my bike is waay too big or not!
Hey guys. Watched both videos about rad fitting. I m 170cms and I ve been riding a ‘19 medium Transition sentinel for some months. It came with a 40mm anvl stock stem and for some time i really didn’t like the bike, super fast but not very playful, and I bented my rear rim, wich is something that didn’t happened in a loooong time. So, I tried a oneup 35mm stem, decreased the stack height from 15 to one 5mm spacer and it felt a lot better, instantly!! Same handlebars btw, oneup 20mm rise. So, I liked your tip and last night i laid on the floor, and it is spot on behind the knuckles 🤘🏻👊🏻. I was really surprised and glad that it matched/ confirmed your rad theory. Thank you
You guys are golden together. Your vids are so great. Can't wait to go home and check all 3 of my bikes. My mountain bike feels better than it ever has after I changed my bar and stem out after the last vid you did on bike fit. Keep making these awesome vids!
I like the theory and approach Lee uses for bike sizing, since it's much better than just the height chart approach. Basic body dimensions are taken into account with this approach. Take note when measuring your rad: 1) wear your bike shoes 2) Feet correctly distance apart (34cm front to back, 28 cm side to side, for 170mm cranks, mid pedal location) 3) hands should be handlebar length apart (I use a string to mark it) For myself, I noted about 30mm difference between measurements without marking my feet and arm positions. Do note that you can further play with stem length, bar rise, bar roll to optimize your position depending if you ride old school or more modern body position. I prefer a higher rise for my riding style and goals 1) comfort 2) easier to try and lift front wheel 3) Not climbing super steeps fast anyway. If I can make it up, that's a win. So like all things, good to understand and apply. Thanks for bringing this approach up and showing how to do it.
My bike measurement was about an inch longer. Short of buying a whole new bike, what can I do? I took his advice and slipped on my high heels and got the measurement correct but riding with flat pedals was a real challenge! I commend his “skills”!
@@rdpurdom-What size is your stem and how many spacers do you run under it? You could try and use a shorter stem with less spacers. That’s worth a try before buying a new bike.
Absolutely fantastic! I am so glad I found your channel. This and the previous bike fit videos were very enlightening for me. And in my late forties, your channel , in general, really speaks to me. Thanks for the content!
I just grabbed my dirt jumper and my trail/enduro bike, laid on the floor to check the R.A.D. Both bikes are in my top 5 favorite bikes I've owned. They feel amazing, it sounds cliche, but they feel like an extension of my body. When I laid down they both fit exactly the same, about 10mm short. Now I gotta do math and make my own rope for when I buy my next bike. Thanks for this update video. You guys rock 🤙🏻
Yet another big thank you to you guys! I’ve just measured my RAD and set my bike up to suit. I dropped the bars and put a 40mm stem on. Turns out it was nearly 2-3inches too long. I always felt like I was falling off the back or could go over the bars at any minute. Always felt really awkward to pedal out the seat, it felt like I was riding a camel, just felt “too big!” But now the difference is incredible. Climbing out of the seat feels as natural as on my road bike!! I also feel way more balanced on my feet! I’m really shocked at the difference it’s made. Thanks again guys! So glad I found your channel! 😁👍🏻👍🏻👍🏻
I have been The Reach Sizing Evangelist...and thanks for making these videos because you guys explain it so much better. I link to these videos several times a week!
Obviously too many comments here to read through, however, I’ll still add my story to bring even more credibility to this amazing video: I’m as average a 40yr old guy can be. 5’9. 190lbs. Went with the Rocky Mountain Instinct BC Edition Enduro as my first MTB... went into the Bike Shop and sales guy walked me through the different bikes and sizes. Then showing me the numbers explained that a M Yeti would be comparable with a L Rocky Mtn. The L Rocky still felt easier to handle then the M Yeti, and the M Rocky my knees were almost smacking the bars. So, I went with a large and I’m RAD neutral!! Yay! Despite the L of the Rocky, it’s fits my average dad bod perfectly. The RAD is everything where bike fit is concerned and I’m pretty sure that Rocky Mountain bike are bigger this year than last... regardless. So much goodness in these vids and I’m loving each one! Keep it up Alex, and thank you!
Kudos to that saleperson!!! We've spoken to store owners who are selling L bikes to 5'7" guys because they know if they try to talk him out of it the guy will walk down the street and buy one.
I can't wait I'm showing up to the bike shop tomorrow to make sure my new EB is the correct size. This video has made so much sense thanks so much for making it!
Long story short: started riding again after a 15+ yr hiatus, progressive geos are alien to me (they're great though!) and the size chart was wrong. After doing a lot of measuring and calculating I managed to get my RAD/spread down to a +10-15mm value (best I can do with this frame without affecting steering), and holy crap things are different. Jumps and pumps feel more natural, the bike feels a lot lighter, I'm not straining my back as much, riding playfully is a lot easier. I was expecting to lose a bit of high speed stability, but nope, quite the contrary. Your videos pointed me in the right direction, thanks!
I just wanna keep it short and say: Thank you very much guys. Since 2015, I was riding a downhill bike (Specialized Status 1 2014) that is basically way too small for me… The reach is shorter than RAD Minus… Recently I bought a Radon Skeen which fits me so much better. It’s modern geometry is much better for me, and it’s only 130/120mm travel trail/down country bike. Nowadays, mtbiking is so much more comfortable for me, because of your golden insights and tips. I’m so grateful for that. Thank you very much. Keep doing that great work!!!❤
This is a great follow up from the previous video. I went out and got Lee’s Dialed book and was able to order my new bike with confidence. I got the right size and I have the knowledge to get it to my perfect RAD. Lots of math and geometry but it makes sense if you take your time. The amazing part was after I understood the numbers I can within a few moments eliminate or verify any bike and move on. That really pared down the field to a manageable number.
One thing that helped me was NOT going off your bike's published reach number, that number is with stock bars and zero spacers. I found a geo calculator that would take spacers into account and I found that my bike as set up is about 10mm shorter than published reach, which is smack dab in the middle of my sweet spot for RAD, published reach would be RAD +
Nice! I knew this longer reach trend was throwing off my fitting. Having longer legs my reach is short for my height. This confirms my sizing down is ideal and not in my head.
These bike fit videos are great but they don’t tell the full story. You need to purchase the Dialed book written by Lee. Recently I have and I couldn’t be happier. Finally I have a formula which quantifies my ideal geometry numbers specific to the type of bike I want to buy. I’m 6 3 and my bikes have always felt too small even though they were XL’s and recommended by the manufacturer as my size. A friend of mine (who shreds btw) has always said on his current bike it feels perfect for him so for curiosity’s sake I measured him and his bike and all the numbers corresponded with the recommendations from Lee’s book! Mind blown! There’s more variables than just RAD which come into play which will help you find your fit and it is all explained in the book. This comment probably sounds like a paid review but rest assured it is not. I’m just so stoked to finally find a defined analysis of Mountainbike bike fit.
Same here. I bought Lee's book and now finally every thing fits me. Before I was just experimenting, and going in the wrong direction! Of course RAD is only one element in the equation of fitting, there's probably to much info in the book to get into one video. And yes Lee, bring it to the UK please!
Late to the party on this video but it has helped so much! I am 6’2”, and because of my height every bike shop I went into has told me I need a size large or extra large. This was really disheartening because the bike shop I was at didn’t have the Specialized P street in my “size”. The guy kept saying the bike looks a little small for you. Luckily I didn’t listen to him and told him the bike felt great. I bought the bike, but the salesman’s words kept ringing in my head really wrecking my confidence in my purchase. Today I measured my RAD for the first time and compared it to my bike and… it is perfect! Turns out I have long arms that make up for my height. So no wonder the bike has always felt great. Thank you for helping me silence that salesman’s voice in back of my head, now I can ride with much more confidence! 🤘
I also checked my RAD for DJ, hardtail, and 20" BMX and ALL had within 1" of 32" RAD. I'm 5'9" with an inseam of 34" and realized a lot of our numbers were the same. Very cool stuff! Great to see things explained in a way in 38 years was never able to understand. You're channel is the PLUG homies 👀 🔥👀 🔥
You guys! This one and your other video regarding bike fit about a month ago, have been watched by myself about six times each. This is so awesome, just dumb it down a bit for me, ha ha gonna reach out and get Lee’s book right away! Holding my breath waiting for your next post and pissed I can’t “like“ them more than once.
I haven't bought a new bike in 20 years, but will do so soon. There's a really good chance that this video has ensured that the next bike I get is going to fit me PERFECTLY and make me absolutely love the bike, no matter what I get. Thanks in advance.
Hey Alex and Lee - just saw this video - awesome! I've been off the bike for 6 months after breaking my hip (in a crash while commuting) but I thought I'd use your advice to check my beloved custom Ti hardtail. I had this built to my own design, based on my understanding of geometry and related it to bikes I knew I loved riding (including my own full sus bike, which is probably a mistake); ultimately, though, the final figures came out of a design that just *looked* right. On paper, it's probably a geometry you'd criticise - long, low and slack with a steep seat angle and a long (485mm) reach. I've loved this bike since the day I finished building it and took it for its shakedown run, though - and now that I've measured both my and my bikes RAD, I know exactly why - absolutely spot on (to within the measurement accuray)!
This was a super fun and useful experiment. Id bought a sized medium Commencal Meta HT this spring and stupidly sold it for a ridiculous reason, immediate seller’s remorse. A day later a nicer spec’d size large Meta HT came up for sale 10 minutes from my house for the same money! I bought it right away figuring I’d probably have to swap a frame out when they became available. For some reason I instantly bonded with it, just felt like a perfect fit. I’m 5’9.3”, which this frame is recommended for 5’10-6’2”. Either way I’ve just been in love with it, though it didn’t make sense on paper. I watched both of your fit tests and tried it out. I quadruple checked my Rad neutral and low and behold the bike and I are within 1/4” of each other! I’d love to see how a shorter stem changes it, but what a validating feeling! Awesome video guys!
Hey guys! Awesome video as usual. Hitting 42 in a few months and just back into MTB after taking a like... 20 year break. Yikes! Trying to learn some of those new tricks! Quick Tip for fitting. Make sure the rope or string you use doesn't stretch too much. If you're a climber think static line vs. dynamic. Twisted instead of woven is better. Paracord will probably work because of the core.
I love you guys. You enrich my life by how much I have learned and the stoke you bring to our world. It's always fun and never boring watching the videos you two produce. You are a force for goodness and may Jesus Christ bless you and fill you all of your days here and for eternity
Now I can B a Super Cool Old Sender with my very own Joy-of-Bike T-Shirt...I promise to wear it out on some jump lines👊. Nice to see you guys Flex’n...MAD GAME...sooo proud of you guys🥺🤙
I’ve found that you may not need to jump to get into the bike stance as shown in 4:30, you can use a tape measure to lower the body. You need to measure 1 crank you are comfortable pedalling on and times that by 2, lets say you have 170mm cranks that would be 340mm or 34cm. Using a tape measure rule it out so it shows 34cm then put the tape measure on the floor and stand over it with your left foot on one side of the tape measure and vice versa. The inner edge of the ball joints or widest part of the foot should be at the tip or end of the measured distance (depending if the foot is forward). When looking at bike geometry measurements online I calculate the hypotenuse of the reach and stack from the smallest size available and take a note of that number, the closer that number is to my RAD the more likely the bike will not fit me as it will be larger and you’d need to take into account the stem length, stack height for the headset, and the handlebar rise which is not shown on the geometry charts. In my head I assume that I would put the shortest (or longest depending on the type of bike) stem possible on it thats on the market, and put flat 0 rise bars on it. Stack height doesn’t really matter at this point because its a few millimetres off from the RAD or to RAD neutral and you can adjust that to get a more upright or lower position. An example of this methodology, using the Marin San Quentin 3 at size S and my RAD being 76cm, shows that its reach and stack (in mm) is 422 and 618 respectively. Using a hypotenuse calculator gives us 748.3mm. Immediately I’m thinking “Yeah this might be too big for me”. When I subtract my RAD of 76cm/760mm from that calculated number (760-748.3) it gives us 11.7mm. This is virtually impossible for me to reach my RAD as I know that adding a stem, slamming it, and adding 0 rise handlebars will put me way over RAD+ with no room to adjust. A case where this methodology puts my RAD in a safe spot would be to use the Kona Process 134 DL 27.5 at size XS. Its reach being 400 and stack being at 585. Its hypotenuse shows that its 708.7mm, now I’m thinking “hey this might give me some room to adjust my RAD”. So, 760-708.7 gives us 51.3mm. Depending on the situation, I could either get a 50mm stem length, slammed with 0 rise bars, OR a 30mm stem with 10mm riser bars with 10mm stack, OR a 30mm stem slammed with 20mm riser bars, OR a 30mm stem with 0 rise bars with 20mm stack height. The extra 1.3mm is pretty unnoticeable and it will only put me slightly into RAD-. So basically, size down tailor up is pretty much what I’m tryna say.
@Flatslide Are you doing your RAD measurement off your knuckle height or how tall you are? I'm 6' 1.5" and my RAD based on how tall I am is 836. I think your RAD measurement based on how tall you are is 840. But my RAD based on my knuckle height is only 800 (I have really long arms) which is considerably less than based on my height. I don't know which measurement to go off.
@@theawesomeone1844 I used the same method shown in the video-with a pencil held in my hand to mark the wall. I purchased my bike 2 years ago based on the fact it was in-store and felt comfortable to ride. I only tried this technique after watching the video to discover my RAD was the same as the bike's. Also my bike has the factory 'bars and stem. There will always be a + or -mm discrepancy :)
@@flatslide3250 thank you for getting back to me. I'm super confused about what size bike to get. Everyone keeps telling me I need an XL or XXL bike, but they feel too long to me. I can't tell if it's because I've been riding the same Med XC bike for the last 15 years and I'm used to a bike that's to small or if a smaller bike really does fit me best. I don't know if I just need to spend time on a bigger bike and get used to it. I'm glad that your bike fits you great! I love my bike but it's stack is only 550mm and the older I get the more uncomfortable it gets.
This method is absolutely spot-on for sizing. I have two frames that are slightly undersized for me that I simply setup to feel right, with a good comfortable lock-in using no measuring at all with stem spacers and riser bars etc. I just checked them against my RAD and they are now near EXACT (
Hmmm thats funny. I calculated reach by the 2.5 formula and got depressed, because i have 35mm to much reach. And with this method, bike fits perfectly, now im happy again 😁🤟 greetings from slovenia
I did the exact same thing with a bike that I have always felt was too long. The height x 2.5 method said it was too long. Then I did that marker measurement and compared to the bike measurement, it said the bike was dead on neutral. Lastly, I did the chairs/stools method and it gave me basically the same result as the height x 2.5 method, the bike is too big! I'm not as happy.... haha
⭐️⭐️⭐️⭐️⭐️ It really works. I went from an 80mm stem with seat all the way back, to a 38mm stem seat all the way forward. It only took 1 ride to adjust to the stem and the seat creaped forward over time.
Wow! I wish that I could DOUBLE SUBSCRIBE to this channel! That is some incredible info! Grabbing my tape measure, shoestring, sharpie, and heading to the garage! Thanks guys!
I recently got a larger bike, and then lengthened the stem on my smaller bike, because the larger bike just seemed to "fit" me better. I just now went out and measured the RAD after watching this video and both bikes measured the same! That's pretty cool!
OK OK! Now, lemme play devil's advocate here: A RAD that matches you means you can generate maximum torque for bunny hops. That's it. It doesn't tell you whether you feel crammed while seated, your hands go numb, whether the bike inspires confidence on steep stuff etc. RAD makes perfect logical sense, but I doubt that it is the holy grail of bike fitting. What are the other possible benefits of going by RAD and what could be drawbacks? Objectively.
@@liwx what I mean is: That's just one aspect of riding, one motion essentially. It certainly is an important one, but as far as I have understood geometry, it's always a trade off. If a bike is particularly good at climbing, it's not as good at descending, if it's awesome through ruff and steep stuff, it might be less agile etc. So, is there a benefit to long bikes? Because I own one and lemme tell you, it feels amazing.
To me the perfect fit is the one that keep your body weight well balanced between both axles. That depends on the bike geometry. And plus, you can tell how nice is a roomy frame compared to a restricted movement one. However this RAD thing gives you a new and different point of view that’s always a very good thing.
@@HeretiCflow I'm with you on this. It has pros and cons. Bike geometry nowadays are long low and slack for descending. It's for the big gnarly stuff that may question the stability of a shorter bike.
One shortcoming with RAD that I have personally experienced is it doesn’t account for the amount height (stack, spacers, bar) vs length (reach, stem) are in that one number. So, you can hit the same RAD with different lengths or heights (if you use string that has one knotted end held at the middle of the BB, the other knot can be moved in arc up and down all at same RAD number) and those translate to very different setups.
This is amazing. All my bikes have different geo.. reach, bb height, bar height, and I feel really comfortable on all of them but couldn't explain why.... Guess what, they all have identical RAD!!!! Great channel, great vibes, keep going
Is this Lee Mccormack? If it is the Dialed books great our cycle shops use the books now for measurements did for us 5 years ago and we still go by it today amazing info! from UK
"...more like a hunk of meat hurtling to an uncertain fate" Many others have already commented on the best line from this video. It's just too damn good not to repeat again. Instant classic!!
Cut handle bars, shortened stem to improve RAD, hinge saved my quads and hamis today during first family ride of the season. Thank you for the videos and lessons. I finally felt like I fit my bike!
@@arneilson4450 I went with the knuckles to ground measure. I'm 6'1, but my wing span is almost 6'5... I also tried the trick at 8:50 and my bike seems to fit me perfect. I have an IBIS Ripley AF XL with a 31mm stem.
Great follow up from previous video. I consciously not paid too much attention to the previous one as I had just bought a new back and didn't want to be missing oartnof the joy of a new bike by figuring out that I took the wrong choice. Truth is that I am always between brand sizes, an usually go for a size smaller. The new Focus Sam2 geometry is a bit different than my Scott Ransom but not too much. I downsized in the Ransom to an M (178cm tall) despite lots of people telling me that I should take an L, and could not be happier. Feels just the right size. When I sat down in a size L, the Focus seemed massive, but as soon as I tried size M I new it was my bike. It just felt right for me. I measured today thr RAD in both bikes out of curiosity and guess what, both where spot on (the Sam2 is 1cm longer) with my meaure! I really think this works. By the way, do let me know if you plan to jump to Spain in your trip to Europe. We have many Brits that come around to MTB. Much nicer weather... ;)
Hi! Great video. Thanks for enlightening us all. One thing puzzled me, though... At 3:42 you mention that the target frame reach is based on a 40mm stem. Since most XC bike stems are at least 60mm long, does it mean that I should/could deduct 20mm from the target frame reach when looking for a XC bike with a 60mm stem? Thanks again and greeting from Rio de Janeiro, Brazil!
I would like to thak you so much for what you are doing! I had a thought that my bike not exactly matches me. So I messed with different stems and bars trying to fix that, but really had no idea what am I doing. I thought I got too low bars or too long reach or whatever. What I was doing is actually trying to fit the bike for a taller person than me. And it did not work, obviously. And I probably would never figured out what am I doing wrong if not you guys! After watching a couple of your videos (especially this one) and making some measurements and checking my bike geometry numbers I found out that my bike fits me just perfectly! So after some calculations and measuremens it turned out the only thing I needed to do is to remove all the spacers from under the stem. This setup has shortened the RAD and suddenly it felt like magic! 200% fit, like the bike was made exactly for me. It feels totally different like it became extension of my body! I was literally shocked by how it felt. I never thought what a big difference can be made by those little spacers. This is the best explaination of bike sizing I have ever seen, that is for sure. After watching a bunch of your videos it suddenly clicks in my head and I understood like everything: bike geometry, reach, stack, why so much different stems and bars, why there are spacers, etc. Now I am not only happy with my bike which turned out to be perfect for me, but I know exactly how and why to set it up. Like of course I do not need any spacers: the frame does the perfect match already and adding up spacers is fitting for a taller person whoes match to the frame is not that perfect. Totally makes sence. No more unconscious tunings and random set up. 😌 Thank you!
I was super relieved to find that using this measurement, my new bike is perfectly RAD, but I’m struggling with understanding how this applies to those with extreme ape index. If I have abnormally long arms, would not my RAD be much shorter than what my bike should be?
I’d assume not, as the RAD defines the exact measurement regarding perfect bike fit. If anything I’d say that this measurement supersedes the ape measurement. I think what you’re saying is a valid point, but I’d assume that your arms would have to be down past your knees (exaggeration) to warrant any concern with a way shorter bike. I suppose people with extreme proportions (really long arms / really short legs, vice versa) other considerations would have to be made. I.e, if you had a really short RAD No, that indicated a Medium frame, but had really long legs that only suited a Large frame, for example, then I’d assume you’d have to buy a Large and use a shorter stem / use bars with a higher degree of back sweep to ensure you hit RAD.
"abnormally long arms" puts your hands closer to your feet. ... the point is to size your bike around you, and that length. If the bike feels smaller under you, then it will also be more playful, nimble, and smaller body movements / body english will be necessary
Huge THANK YOU for this video, and your other ones about geometry and bar width! I'm one of probably many people who bought a size L following the brand's size chart (Giant Reign 29), when after all I should have trusted my gut and bought an M size. It felt "large" from the start, but not CRAZY oversized, also it was my first "modern" geo enduro bike after a long hiatus (I'm 37 yo), and i DID want a long / slack bike that induced some confidence, so I ended up keeping the L bike and thought I just have to get used to it. Little over a year later, I DID get used to it better, but it always felt huge, sluggish, and not perfectly at home, especially compared to my 20yo allmountain fully with ancient geo that is WAY smaller. So i started checking prices for used frames in size M, but no luck - instead i found YOUR VIDS! And after some measurements i figured my RAD on the bike was a good 6 cm over what it should be ideally... Long story short: I ended up cutting my 800mil bar by 20mm (HUGE difference!), turned it a little further back to reduce upsweep, and dropped 10mm of spacers below the stem. Result: I'm now within 2,5 cm of my of my "ideal RAD", and the bike feels WAY more nimble, agile and properly sized! I'm considering swapping to a shorter stem, which would bring me dead on my RAD, but i feel that might even be too much. Bike as it is now feels already SO much better and more the way i want it to feel, it's crazy! Manuals / Wheelies are still not easy, as obviously my wheel distance didn't change, but at least now i can ATTEMPT them, and it feels like something I can train towards, instead of feeling just insecure and lacking power. THANK YOU!
I have a long torso and kind of short legs and demo'd a few bikes before I bought my latest (unfortunately too long, but that's COVID supply chain for ya... glad to have anything). The description of bike geo trends is I think not the full story re: root cause... steeper seat angles and slacker HA get the rider more forward which IMO really helps with traction on descents even if you haven't been coached on riding position (I think these 2 guys don't buy that, but with the front wheel more forward you've got a longer lever arm). On the climbs, with steeper SA, your rear end doesn't shift back as much when your dropper is extended. Seems to me you can get away with a smaller bike now without the front wheel unweighting on step ascents, which is an issue I had 6 years ago on a slack SA medium (I was in between sizes). During my pre-COVID demos, I universally enjoyed climbing bikes with steeper SA. I guess this would matter more for people with long legs and short torsos. You can compare estimated top tube and reach between bike models... the ETT number was a pretty good indicator of seated roominess (mediums seem to range from ~580mm [my OG TR Patrol] to 615mm [Revel Rail]) and reach of standing room. I know stack height matters too but it helps to gauge how it'll feel when, especially now, it's really hard to get a leg over a demo bike.
Seems to contradict RAD. I have short legs and long torso/arms, so my RAD is shorter than it would be for a normal person of my height (my arms are closer to the ground). But I actually have a greater range of motion due to having longer arms!! So I should be on a larger, not shorter bike, contradicting RAD. There is also the matter of my body’s center of mass being more forward than a regular person, so this also suggests a longer reach is needed to prevent the OTB feeling when descending.
@@totalcranker I think my comment only applies to the method of holding a pencil and drawing line on the wall. There are other ways to measure your RAD and they may work better for our body type. Having said that, I measured my my bike and my RAD using this method and my RAD was only 2cm shorter than the bike's RAD (M frame and 172cm tall) so we're talking small differences either way.
This works a lot better than the height based formula as it takes arm length into account. This also explains why my bike is so comfortable despite the published reach of 475mm being at RAD+ for me using the arm measurement forumla, with my bars and spacers I'm at 465, right in the middle of my RAD sweet spot, the height based reach would have me at 445
I don't know how the knuckle height RAD takes into account arm lenght. If anything it ignores it. I'm 6' 1.5" which gives me a RAD based on my height of 836, but my RAD based on my knuckle height is 800, the same as Alex, who, I believe he said he is 5' 9". Based on my knuckle height Alex and I should be on the same size bike, but if he is 5' 9" his RAD based on how tall he is, is 783. For having the same knuckle height RAD of 800, our RAD based on how tall we are is different by 53 mm.
Easy to follow video. My new bike felt a little short to me, it measured 79cm and I needed 82cm. Swapped the stem and handlebars now have 83cm which feels a whole lot nicer, there is still some adjustment to bring it back if needed. The wider handlebars I put on made a big difference too, the whole thing feels right now.
I love this video. Couldn't say more about how much this has opened my eyes to bike fit issues and given me possible explanations for why my bike probably isn't for me (even though I pass the lay down test). However, I do think the fitting methodology here should be improved to account for rider proportions. I'm a tall rider at 6'5", and most of my height is in legs. Even with getting the rad right, I think most bikes' stack/reach ratio, is too small for my disproportionately long legs, so I end up with my torso more parallel to the ground, and my weight all over the place forward/aft. I either have tons of weight on my hands and my head in front of the bars, or my ass is above the rear axel. For reference, I have a Ripley V4 XL which is 500 reach, 631 stack, and a 1.26 stack/reach ratio. I haven't had a chance to ride anything else recently since there are no demos, but my hunch is that something with a ratio above 1.30, and a reach around 490 (which ironically is what Lee's height in cm * 2.50 = reach equation spits out for me) will be better. Need to do the actual rad measurement though, so this hunch is kind of uninformed at the moment. I just suspect that if you don't account for this, on the average bike (or my Ripley anyways) either your long arms make you stand too tall putting your weight too high, or your long legs put your butt in the air and make you too bent over unable to keep your weight between the axels (rad remaining equal in both cases). Really the question is "is there an optimal torso angle over the bike?" Then with arm, torso, and leg measurements you could REALLY dial in fit.
How to get RAD using geometry charts. You can get pretty close using a right triangle calculator. Pythagorean theorem, Insert stack and reach into the calculator. This will be short cause it does not take into account headset and bars on stack measurement. Guys what would be a good "average" measurement to add to stack?? Example Nukeproof Scout I added 9cm for headset and bars from website info, 73 squared (stack+9cm) + 45 squared (reach) = 85.75cm. My RAD barefoot is 85! so pretty good! I understand that if you add to the stack it will decrease the reach because the head tube is on an angle so you can knock off a couple cm if you want this should get you pretty close. Thanks for the info, subscribed!!
Great job it worked for me too! 2021 Norco Range VLT Medium stack (602+90)^2 + reach (450)^2 = C^2 = 825mm. I measured it and got the same number. Easy to punch in the reach and stack on a pythagorean theorem calculator online and I added 70mm to stack for spacer height plus 20mm for handlebar rise.
Thank you! Amazing info! I've been struggling against the mainstream fitment ideology. But your perspective 100% validates my real life experience with how my body feels when riding. I don't need to be all stretched out to "get maximum pedaling power".
Hi, Lee! Thank you very much for the book ‘Dialed’, it is very helpful. I have a question though. Is RAD and RAAD measurements are performed with sagged bike or not? I’ve found this moment crucial for hardtails. Thank you!
This makes more sense - many thanks. Since the last video I have been trying to do something like this. Maybe I'll be the "Guy" lying on my back trying the quick hack option when unable to measure!
Great videos, love watching them. Just a question about the bike/body position at the core of the RAD fit theory. When you measure, eg 4.48 and 9.12, the feet are flat but when actually riding and executing that move Alex ( and probably all riders) are up on the balls of their feet eg 7.37. For me that extends the measurement by 30mm. Is this relevant ?
I have been fine-tuning things like saddle height to great effect. Just for the goof I discovered my body's RAD is 77cm, and my bike is 75.6. I knew it felt good, and nice to see the numbers support it.
I'm 5ft 8 and I just got a brand new NS Bikes define AL in small for £1230. I've always ridden a medium frame but got this to flip because it was such a good deal. Looks like it may not be leaving my shed now 😁👍
Steep seat tube angles aren't to create more clearance for the rear wheel, suspension, etc. The reason is to shift the rider's weight forward for better weight distribution when climbing. This is why you'll see bikes built to ride up steep mountain terrain with 77-78 degree STAs and bikes built for XC with 75-76 degree STAs.
Took the advice, and at 5ft 7in, I bought a small Trek Slash, as even the small has a 425mm reach! I came from a medium Scott Spark in comparison, and at 440mm reach, it also has a 60mm stem. The small Slash has 15mm less in reach and 25mm less in stem length, and my RAD is fairly spot on - result on the trail is I don't feel like I'm leaning on the bars anymore...
Glad you followed up with this after the last video. Going off of height is certainly inaccurate. For instance, I'm slightly over 6 foot 2 with my shoes on but I have long legs and average arms for my height. This lengthens my rad number. However, there are a few other variables here. Most people position their pedals towards the front third of their feet which causes them to leverage through the balls of their feet with their heels up which extends their rad number. Also, the position of your hands while leveraging is typically 2 or 3 inches in front of your thighs which also would increase your rad number. I would suggest measuring your rad with your heels slightly up and your hands two or 3 inches in front of your thighs.
Your channel is my favourite YT channel, better than GMBN. Even thought they're great too. I followed your instructions and surprisingly my bike as it is setup is at my RAD number. I'm blown away. I'm 186cm and the bike is a Large Norco Fluid HT1. The manufacturer recommends I use an XL frame.
Thank you ! But can you explain what with people with longer or shorter arms ? Does it mean that with longer arms I should get smaller bike? and opposite, with shorter arms bigger bike would fit better ?
So fun!... today I was changing the flip ship on my bike, steertube spacers, and the stem on my bike for a shorter one (because Im selling my expensive Burgtec one to make money...), so, I literally spent all my day trying to think on all my previous bikes reach+stem+bars combos, doing calculations, checking videos about cockpit setup and effects, etc... and boom!!, after I saw your video, I wrote my body RAD and my bike RAD and it's my perfect RAD jajajajja... Thanks guys that's my years of testing in 3 minutes >< jajaj
I would totally lie on my back to size a bike at a demo. That would be one of the least embarrassing things I've ever done in public. Thanks for this video though! It turns out I've been riding rad double minus (ridiculously small) on my hardtail down chunky black trails. For this reason I was convinced a Large Revel Rascal was going to be too big for me. Turns out it's not. Medium will be rad minus. Large could be rad plus OR rad neutral. BTW I'm only 179cm but that really does put me on a Medium or Large Rascal (still Medium on other brands though) I just M and Large yesterday and they both feel amazing. I really am right in the middle. Going to demo some again and will re-measure. My ideal would be rad neutral for this bike.
Here’s a thought: It appears that the RAD measurement on the bike (bottom bracket to middle of handlebars) is somewhat close to the 3rd side of the triangle made up of the stack and the reach. So could Pythagorean’s theorem be used to approximate the RAD measurement? For example: RAD = √((stack2)+(reach2)); the 2s are supposed to be square subscripts So a bike with a reach of 450 and stack of 612 would have an approximate RAD of 760. Then perhaps add another 5mm or so to that to reach the invisible line, approx. 765.
Yes, absolutely. This is what I've suggested too. You have just add another 100 mm to compensate for the cockpit which includes head post, stem, handlebars raise and so on.
@@mishkathebear This is an older video so don't know if I'll get an answer but would you really add 100 mm instead of 10 mm? 10 centimetres sounds like a lot :D contemplating between two bike sizes..
@@irisvesamaki7665 Im no expert on this, but you will definitely need to add a couple of centimeters. On my hardtail which has 70mm stem a 20mm spacer I had to add round 100mm (10cm) Handlebar: 9-degree backsweep, 15mm rise, 31.8mm; 740mm width
wish i new this before i purchased my bike! bought a medium for me a small for the mrs, (same bikes) i have always felt better on her small. now i know why!
I looked thru the comments and couldn't find this question and since there are 753 of them I'm just going to ask it... If two people are the same height but one person has a longer reach than the other (longer arms), the person with the longer reach would have a smaller RAD than the other and may need a smaller bike although they have a longer reach. Am I wrong? Please correct me if I am.
@@spritle1700 I mean, if you follow the only one measurement presented in this video, then yes. Longer arms&same height means smaller bike. Crazy isn't it?
Before you post a question. Please take a moment to look through the comments because there is a very good chance it has been answered. Keep shreddy!!!
I’ll start off on a positive note here and say, that it is great to have a different approach and to question everything that we are told. However, I have two main problems, and dare I say concerns, with Lee’s advice. First, Lee presents his information, for my liking at the very least, with too much certainty and conviction. As if his “R.A.D” is singularly the only correct way to size a bike. The way he speaks leaves no room for nuance, compromise or rider preference. It is a “I am right, you are wrong attitude.” The world is many shades of grey. R.A.D. appears to be based off of one premise, the idea of a rider maximising their torque, which in itself, is a valid idea. This brings me to my second problem with this advice. The idea of maximising, or even utilising this idea of maximum torque excludes many, if not most other areas of the trail - how often do you ride your local trails trying to bunny hop as high as possible over every obstacle? Not many riders - actually none - that I see, and certainly not me. If this is you though, then potentially the R.A.D. measurement is for you. I would argue that this sizing idea, which, let’s be honest is to go shorter, ignores the many benefits of modern longer bike geometry which can not only increase rider confidence but potentially their safety. I would argue that So many manufacturers can’t be wrong. I’m sorry, but at the end of the day, I completely disagree with this advice for general, aggressive trail riding. But if you want to win a bunny hop competition then... thoughts @joy of bike?
@@thegriff9425 - hahaha, that's funny! I hope you are a grown up man, that can do your own filtering ;-) When that is said, I can't think of two more opposite movements than bunnyjumps and pedaling up a hill. And if this way of measuring take both of this positions into account, then I guess it could be pretty accurate.
Both me and a friend did the measurement, and afterwards checked our bikes. We both have bikes that feels perfect, and both this bikes did match our RAD. We also both have bikes that we had a suspicion being too big, which this measurement did actually show.
If I will trust this 100% next time, buying a bike, I don't know. But it did tell me that my latest bike is to big, which I for sure can feel. And that bike was bought after using the bike company's own sizing app.
Eh, I like your videos but I'm not sold on this or your other fit video. If you have two people that are exactly the same height, one with long arms and the other with short arms, according to this technique the person with long arms will require a smaller bike and the person with short arms will require a larger bike...
@@thegriff9425 But wouldn't having access to more torque help with many aspects of aggressive trail riding besides bunny hops? It will definitely help with pumping, and pumping is a technique undergirding jumping, as well as simple things like picking up speed on the trail. All of which is definitely part of "general, agressive trail riding." So that suggests that maximizing torque by having the right R.A.D. will actually help with trail riding. Also, I am not sure that "modern longer bike geometry" has to be sacrificed in order for RAD to apply. Doesn't the stability of "longer" bikes have more to do with a longer wheelbase (hence the steep head tube angle) than a different RAD? Seat tube angle + head tube angle can be adjusted so that RAD is the same or smaller even on a "longer" bike.
@@thegriff9425 from watching this and their other videos I believe the premise is that an optimal fit based on RAD is primarily to reduce injury. Rider comfort and optimizing power (torque) are merely beneficial effects of RAD.
“A hunk of meat hurtling to an uncertain fate” That, right there, is absolute GOLD! 🏅
That will be my phrase of the day.
painfully accurate
At 180 cm I was riding 481 reach for a short period. 100÷ my experience. Settled at 465-470. Shorter feels even better most of the time, but I find that sometimes I have to move too much (hard braking after a drop is the best example).
Namastoke! May I recommend making an addendum video where you fix different setups? Stem rise/length/angle/stack, consequences of having grips behind or too near steering axis. Sometimes the solution isn't as simple as a stem change in my experience!
After a clinic with Lee, I swear by this method. With hardly any bike inventory in Australia, knowing my RAD and the frame measurements accessed via Lee's book Dialed, I bought a bike sight unseen and it fits like magic
How can you tell what a bikes RAD will be without measuring it in person? @Eric Lemond
@@theawesomeone1844 maybe with the geometry?
I’m tired of being that hunk of meat waiting for impact. That’s why I subscribed. My new fav mtb channel
Me too. My ribs said go measure your RAD
A good tip for accuracy, double your crank length and make two marks on the floor at that measurement, (175mm crank = 350mm) when you position your feet, put the ball of your foot by each mark. Having your feet too far apart or close together can change your height.
I also found its easier to hold a tape measure or string, or even a handlebar to get my hands at the exact width. I know none of this is exact science but it helps to get consistent measurements.
Ive been wondering if I should really be on a bigger frame but Rad pretty much confirms that what Ive felt for years is correct. I'm 6'2" and I like a 475 reach, Large on most frames while a lot of "fit guides" put me on an XL.
Nice job guys
This ^^^^ i was so confused as the pevious height calculation method had my rad perfect even with a 70 mm stem length.
Then when i used the string method i was about 70mm rad + but had forgotten to hold my hands at handlebar width which made all the difference.
I came here to point this out also. Handlebar width makes a difference. This method of fit definitely works though. All the bikes I own that I really like, are at my rad.
Used this to get a new bike for my wife also that was previously uncomfortable on her bike.
I don't know if you will ever see this @JoyofBike but this video and the handlebar one completely changed my riding experience. I cannot thank you enough!
Measured my RAD number at 86cm and was very pleased to find out my Meta HT (size L) was 85cm. I remember I changed my order from Med to Large after I already paid, now I've got proof that was the right choice.
Bro how tall are you? I ordered an M but I am not sure because of the reach... reach is only 420. I am 176cm. My inseam is around 79 and my RAD is 80 if i am not wrong. Armlength like 60. 🤔🤯😅
Same reason I changed my order from XL to L after I payed for the bike. I'm spot on 85cm RAD. I'm also almost a "perfect" human sizewise, 189cm tall with 88cm inseam and apeindex of 1 (lol)
I stumbled across your channel when searching how to get a better bike fit for my wife. I'm addicted... thanks for sharing your wisdom with the world.
A UK series!! Yeah make it happen. Love this channel. Can’t put my finger on it but there’s something different and relatable about you guys. Always entertaining and informative.
Appreciate you!!
I agree best guys in mtb world for sure, they just explain things in an easy to understand way! Props guys
So I had a buddy show me the last RAD video after riding a skills park one day. After stopping to think about how heavy handed I was on the down hills and how hard jumping along with other skills were for me I did the math. Turned out I’m an in between. Swapped from a XL to an L, and the large just fell right in place. Weather has kept me from riding, but I’m stoked to get it on the trail. P.S. I was already looking at new bikes! The video just saved me from buying another oversized bike.
I can't understand the thumbs down you got. Good info, it all makes sense. 👍Lee has his own thoughts about mountainbiking and isn't just copying what the majority is telling you about it.
After 7 years of riding and multiple bikes, I shortened the stem on my current bike to match the R.A.D. you suggested. All I can say is "WOW, what a difference!". The bike feels better than ever and I have noticeably more control. Even better is being able to take this to any bike. It 's a game changer. Much appreciation for sharing!
Mind blown. I just did this measurement and both my bikes with out me even taking that much thought i have set up the to my needed RAD. My hardtail is with a 50mm stem size medium and my full sus is with a 60mm stem size medium but with a head angle kit (making it slacker) intalled. 🤯 I set them up my self when i got them just by sitting in the bike and riding a few times made the changes and been happy first time now i have the proof. Another great video.
I just wanted to say thank you to you both. Once I was able to dial in my RAD, it was as if the clouds parted and light shined down. I had complete control of my bars with no weight in my hands and I was floating and flying with all my weight through my feet in the center of my bike. I controlled the bike and not the bike controlling me. It has opened up a whole new feeling to biking and it is spectacular.
This R.A.D concept is interesting. I appreciate the intent of getting a bike that allows the rider to be as dynamic as possible, but I can't help but thinking that this concept is going to result in people optimizing for one ride characteristic/criteria at the expense of others, rather than striking a balance between the wide range of desirable characteristics. The R.A.D on my enduro bike measures about 40-50mm longer than the recommendation, while my dirt jump hardtail is exactly the recommended R.A.D length. Having ridden the DJ bike a lot recently, I can definitely feel how that size maximizes my ability to ride dynamically (move my hips, generate power when hopping, manual, etc.). Maximizing this trait makes a lot of sense on a dirt jump/pumptrack bike.
However, if we accept that a longer bike is more stable at speed, it seems worthwhile to compromise some of that dynamism created by the short reach/R.A.D for more stability in an enduro or DH application, where you're riding faster and over rougher terrain, doesn't it? There is only so much length you can add to a bike while keeping the same R.A.D (slackening the head angle, lengthening the chainstay, etc), and each of the changes will also have an impact on the handling characteristics. My sense is that I gain more stability by adding length than I give up in that dynamic ride quality the R.A.D seems to maximize. It takes a bit more effort to manual or pop my enduro bike, but that seems like a worthwhile trade off for the additional stability brought by the longer reach/R.A.D - any thoughts on that?
I also wonder if targeting R.A.D without considering other aspects of the bike's geometry and components will result in sub-optimal performance. For example, you talk about shortening the stem and adding backsweep to the handle bars. While this will shorten the R.A.D, it can also dramatically reduce the amount of weight the rider has on the front wheel, which can really reduce front end traction, which is essential for confident cornering. Similarly, for shorter/medium sized riders, sizing down to achieve on optimal R.A.D might result in them riding bikes with significantly longer chainstays than reaches, which can lead to some strange handling characteristics. Would these riders be better suited to a bike with a longer R.A.D, but a more balanced bike, rather than optimizing their R.A.D at the expense of some other handling traits?
GREAT point & GREAT questions. imo changing the stem bars seat positioning is a great thing... but if you go to far it seems like one would have a the worse of both worlds. So, dropping down a frame size and minor tweaks to positioning is the way to go. YES: Speed is the trade off in my (limited, less learned) opinion. **The gnarlier it gets, the twistier is gets, the steeper it gets, the smaller I want my frame size** -- but I still want 29" wheels, not smaller, because of the gnarl .. BUT, the trade off is for speed on a longer wheel-base bike... which means you must, must, weight the front end more. So, you are on target in my opinion. Here is mine questions that pertain to your's: Question: **Isnt RAD sizing is FAR more important the heavier the bike is? and The longer the wheel-base is?*** I ask because the new high performance Electric mtn bikes are so freak'n heavy, and the wheel size so large, and the wheel base has gotten so long. The bike shops are pushing me to the largest frame size. Seems they don't like me on a 2021 (old school large) which is smaller than the newer year (2022) : they want me on the largest new school (2022) large. Anyway: I test rode 5 brands, and 3 sizes in the preferred brand, and the smallest one (RAD + per my string) was the only one I could wheelie. Longer stem on that same bike, per the shop's recommendation, and my ability to wheelie was GONE.
So, rather than drop $11,000.00US on a bike I am unsure of: I ran out an bought a Craiglist special (Epic, carbon fiber, 26" wheels, non-electric dually) in a frame size using RAD+, and it feels really good. I have to watch my speed for corners, most likely because I'm still not used to the smaller size.
What say you to my points? Any input?
great points to consider for the varying types of bikes and riding styles/levels. Definitely more info needed here to shore up some of these and test in real world applications.
Definitely one of my favorite channels on RUclips. I love the positive energy. I can't wait to check the fit of my bike. Thank you both for your time and positivity.
Thanks brother
@@JoyOfBike - I measured and I have the same RAD as you. I have ordered a shorter stem to bring my current bike in line - Thanks for the justification to buy new parts :)
After watching the step stool video in the cold garage I was obsessed with having a set of stools to check my RAD! Having seen this video and realizing I can just lay on my back like you would to practice tuck no handers and bar spins was such a good moment! Time to find out if my bike is waay too big or not!
Hey guys. Watched both videos about rad fitting. I m 170cms and I ve been riding a ‘19 medium Transition sentinel for some months. It came with a 40mm anvl stock stem and for some time i really didn’t like the bike, super fast but not very playful, and I bented my rear rim, wich is something that didn’t happened in a loooong time. So, I tried a oneup 35mm stem, decreased the stack height from 15 to one 5mm spacer and it felt a lot better, instantly!! Same handlebars btw, oneup 20mm rise. So, I liked your tip and last night i laid on the floor, and it is spot on behind the knuckles 🤘🏻👊🏻. I was really surprised and glad that it matched/ confirmed your rad theory. Thank you
You guys are golden together. Your vids are so great. Can't wait to go home and check all 3 of my bikes. My mountain bike feels better than it ever has after I changed my bar and stem out after the last vid you did on bike fit. Keep making these awesome vids!
Awesome! Thank you!
I like the theory and approach Lee uses for bike sizing, since it's much better than just the height chart approach. Basic body dimensions are taken into account with this approach.
Take note when measuring your rad:
1) wear your bike shoes
2) Feet correctly distance apart (34cm front to back, 28 cm side to side, for 170mm cranks, mid pedal location)
3) hands should be handlebar length apart (I use a string to mark it)
For myself, I noted about 30mm difference between measurements without marking my feet and arm positions.
Do note that you can further play with stem length, bar rise, bar roll to optimize your position depending if you ride old school or more modern body position.
I prefer a higher rise for my riding style and goals
1) comfort
2) easier to try and lift front wheel
3) Not climbing super steeps fast anyway. If I can make it up, that's a win.
So like all things, good to understand and apply. Thanks for bringing this approach up and showing how to do it.
My bike measurement was about an inch longer. Short of buying a whole new bike, what can I do? I took his advice and slipped on my high heels and got the measurement correct but riding with flat pedals was a real challenge! I commend his “skills”!
@@rdpurdom-What size is your stem and how many spacers do you run under it? You could try and use a shorter stem with less spacers. That’s worth a try before buying a new bike.
Absolutely fantastic! I am so glad I found your channel. This and the previous bike fit videos were very enlightening for me. And in my late forties, your channel , in general, really speaks to me. Thanks for the content!
Great to hear!
I just grabbed my dirt jumper and my trail/enduro bike, laid on the floor to check the R.A.D.
Both bikes are in my top 5 favorite bikes I've owned. They feel amazing, it sounds cliche, but they feel like an extension of my body.
When I laid down they both fit exactly the same, about 10mm short.
Now I gotta do math and make my own rope for when I buy my next bike.
Thanks for this update video.
You guys rock 🤙🏻
Man I like that size. Just a tad short is nice!!!
Great!!
The four thumbs down have got to be people that are realizing they bought a bike way too big for themselves. 🤔
Or the dude from Pole ;)
@@luvinfunvan 🤣🤣
🤣🤣🤣
It‘s the dude trading a large SB150 for some chairs.
@@luvinfunvan what dude exactly?
This channel open my eyes completely!
Yet another big thank you to you guys! I’ve just measured my RAD and set my bike up to suit. I dropped the bars and put a 40mm stem on. Turns out it was nearly 2-3inches too long.
I always felt like I was falling off the back or could go over the bars at any minute. Always felt really awkward to pedal out the seat, it felt like I was riding a camel, just felt “too big!”
But now the difference is incredible. Climbing out of the seat feels as natural as on my road bike!! I also feel way more balanced on my feet! I’m really shocked at the difference it’s made.
Thanks again guys! So glad I found your channel! 😁👍🏻👍🏻👍🏻
Super stoked for you!!
I have been The Reach Sizing Evangelist...and thanks for making these videos because you guys explain it so much better. I link to these videos several times a week!
Obviously too many comments here to read through, however, I’ll still add my story to bring even more credibility to this amazing video: I’m as average a 40yr old guy can be. 5’9. 190lbs. Went with the Rocky Mountain Instinct BC Edition Enduro as my first MTB... went into the Bike Shop and sales guy walked me through the different bikes and sizes. Then showing me the numbers explained that a M Yeti would be comparable with a L Rocky Mtn. The L Rocky still felt easier to handle then the M Yeti, and the M Rocky my knees were almost smacking the bars. So, I went with a large and I’m RAD neutral!! Yay! Despite the L of the Rocky, it’s fits my average dad bod perfectly. The RAD is everything where bike fit is concerned and I’m pretty sure that Rocky Mountain bike are bigger this year than last... regardless. So much goodness in these vids and I’m loving each one! Keep it up Alex, and thank you!
Kudos to that saleperson!!! We've spoken to store owners who are selling L bikes to 5'7" guys because they know if they try to talk him out of it the guy will walk down the street and buy one.
I can't wait I'm showing up to the bike shop tomorrow to make sure my new EB is the correct size. This video has made so much sense thanks so much for making it!
Long story short: started riding again after a 15+ yr hiatus, progressive geos are alien to me (they're great though!) and the size chart was wrong. After doing a lot of measuring and calculating I managed to get my RAD/spread down to a +10-15mm value (best I can do with this frame without affecting steering), and holy crap things are different. Jumps and pumps feel more natural, the bike feels a lot lighter, I'm not straining my back as much, riding playfully is a lot easier. I was expecting to lose a bit of high speed stability, but nope, quite the contrary.
Your videos pointed me in the right direction, thanks!
I just wanna keep it short and say: Thank you very much guys. Since 2015, I was riding a downhill bike (Specialized Status 1 2014) that is basically way too small for me… The reach is shorter than RAD Minus…
Recently I bought a Radon Skeen which fits me so much better. It’s modern geometry is much better for me, and it’s only 130/120mm travel trail/down country bike.
Nowadays, mtbiking is so much more comfortable for me, because of your golden insights and tips. I’m so grateful for that. Thank you very much. Keep doing that great work!!!❤
ofc the reach is shorter than rad.. wtf are yout talking about
This is a great follow up from the previous video. I went out and got Lee’s Dialed book and was able to order my new bike with confidence. I got the right size and I have the knowledge to get it to my perfect RAD. Lots of math and geometry but it makes sense if you take your time. The amazing part was after I understood the numbers I can within a few moments eliminate or verify any bike and move on. That really pared down the field to a manageable number.
Love it!!
One thing that helped me was NOT going off your bike's published reach number, that number is with stock bars and zero spacers. I found a geo calculator that would take spacers into account and I found that my bike as set up is about 10mm shorter than published reach, which is smack dab in the middle of my sweet spot for RAD, published reach would be RAD +
@@mrvwbug4423 do you have a link for this calculator?
Nice! I knew this longer reach trend was throwing off my fitting. Having longer legs my reach is short for my height. This confirms my sizing down is ideal and not in my head.
These bike fit videos are great but they don’t tell the full story. You need to purchase the Dialed book written by Lee. Recently I have and I couldn’t be happier. Finally I have a formula which quantifies my ideal geometry numbers specific to the type of bike I want to buy. I’m 6 3 and my bikes have always felt too small even though they were XL’s and recommended by the manufacturer as my size. A friend of mine (who shreds btw) has always said on his current bike it feels perfect for him so for curiosity’s sake I measured him and his bike and all the numbers corresponded with the recommendations from Lee’s book! Mind blown! There’s more variables than just RAD which come into play which will help you find your fit and it is all explained in the book. This comment probably sounds like a paid review but rest assured it is not. I’m just so stoked to finally find a defined analysis of Mountainbike bike fit.
Same here. I bought Lee's book and now finally every thing fits me. Before I was just experimenting, and going in the wrong direction! Of course RAD is only one element in the equation of fitting, there's probably to much info in the book to get into one video. And yes Lee, bring it to the UK please!
Totally agree, I have the book as well and love the MTB-specific approach to fit.
Late to the party on this video but it has helped so much! I am 6’2”, and because of my height every bike shop I went into has told me I need a size large or extra large. This was really disheartening because the bike shop I was at didn’t have the Specialized P street in my “size”. The guy kept saying the bike looks a little small for you. Luckily I didn’t listen to him and told him the bike felt great. I bought the bike, but the salesman’s words kept ringing in my head really wrecking my confidence in my purchase.
Today I measured my RAD for the first time and compared it to my bike and… it is perfect! Turns out I have long arms that make up for my height. So no wonder the bike has always felt great.
Thank you for helping me silence that salesman’s voice in back of my head, now I can ride with much more confidence! 🤘
A Big thank's from France because i'm deep in this problèmes of géométrie
I also checked my RAD for DJ, hardtail, and 20" BMX and ALL had within 1" of 32" RAD. I'm 5'9" with an inseam of 34" and realized a lot of our numbers were the same.
Very cool stuff! Great to see things explained in a way in 38 years was never able to understand.
You're channel is the PLUG homies 👀 🔥👀 🔥
I had to look up plug. Thank you!!
You guys! This one and your other video regarding bike fit about a month ago, have been watched by myself about six times each. This is so awesome, just dumb it down a bit for me, ha ha gonna reach out and get Lee’s book right away! Holding my breath waiting for your next post and pissed I can’t “like“ them more than once.
Super stoked it's helping
I haven't bought a new bike in 20 years, but will do so soon. There's a really good chance that this video has ensured that the next bike I get is going to fit me PERFECTLY and make me absolutely love the bike, no matter what I get. Thanks in advance.
Heck yeah!
This is great info, thanks, guys. And if I can get "a hunk of meat hurtling toward an uncertain fate" into a produced ad, I'll send Lee a royalty.
Best video on RUclips about how to chose a bike for your size !
Glad it was helpful!
Hey Alex and Lee - just saw this video - awesome!
I've been off the bike for 6 months after breaking my hip (in a crash while commuting) but I thought I'd use your advice to check my beloved custom Ti hardtail. I had this built to my own design, based on my understanding of geometry and related it to bikes I knew I loved riding (including my own full sus bike, which is probably a mistake); ultimately, though, the final figures came out of a design that just *looked* right. On paper, it's probably a geometry you'd criticise - long, low and slack with a steep seat angle and a long (485mm) reach. I've loved this bike since the day I finished building it and took it for its shakedown run, though - and now that I've measured both my and my bikes RAD, I know exactly why - absolutely spot on (to within the measurement accuray)!
This was a super fun and useful experiment. Id bought a sized medium Commencal Meta HT this spring and stupidly sold it for a ridiculous reason, immediate seller’s remorse. A day later a nicer spec’d size large Meta HT came up for sale 10 minutes from my house for the same money! I bought it right away figuring I’d probably have to swap a frame out when they became available. For some reason I instantly bonded with it, just felt like a perfect fit. I’m 5’9.3”, which this frame is recommended for 5’10-6’2”. Either way I’ve just been in love with it, though it didn’t make sense on paper. I watched both of your fit tests and tried it out. I quadruple checked my Rad neutral and low and behold the bike and I are within 1/4” of each other! I’d love to see how a shorter stem changes it, but what a validating feeling! Awesome video guys!
Hey guys! Awesome video as usual. Hitting 42 in a few months and just back into MTB after taking a like... 20 year break. Yikes! Trying to learn some of those new tricks! Quick Tip for fitting. Make sure the rope or string you use doesn't stretch too much. If you're a climber think static line vs. dynamic. Twisted instead of woven is better. Paracord will probably work because of the core.
A few $$ for a small tape measure is probably a good investment! Bikes are big $$$$$$$$!
I love you guys. You enrich my life by how much I have learned and the stoke you bring to our world. It's always fun and never boring watching the videos you two produce.
You are a force for goodness and may Jesus Christ bless you and fill you all of your days here and for eternity
Bless you brother!!
For the longest time I thought my bike is too small for me. This video tells me it's the right size😅😅😅👏🏽👏🏽👏🏽
😅
Now I can B a Super Cool Old Sender with my very own Joy-of-Bike T-Shirt...I promise to wear it out on some jump lines👊. Nice to see you guys Flex’n...MAD GAME...sooo proud of you guys🥺🤙
I’ve found that you may not need to jump to get into the bike stance as shown in 4:30, you can use a tape measure to lower the body.
You need to measure 1 crank you are comfortable pedalling on and times that by 2, lets say you have 170mm cranks that would be 340mm or 34cm. Using a tape measure rule it out so it shows 34cm then put the tape measure on the floor and stand over it with your left foot on one side of the tape measure and vice versa. The inner edge of the ball joints or widest part of the foot should be at the tip or end of the measured distance (depending if the foot is forward).
When looking at bike geometry measurements online I calculate the hypotenuse of the reach and stack from the smallest size available and take a note of that number, the closer that number is to my RAD the more likely the bike will not fit me as it will be larger and you’d need to take into account the stem length, stack height for the headset, and the handlebar rise which is not shown on the geometry charts.
In my head I assume that I would put the shortest (or longest depending on the type of bike) stem possible on it thats on the market, and put flat 0 rise bars on it. Stack height doesn’t really matter at this point because its a few millimetres off from the RAD or to RAD neutral and you can adjust that to get a more upright or lower position.
An example of this methodology, using the Marin San Quentin 3 at size S and my RAD being 76cm, shows that its reach and stack (in mm) is 422 and 618 respectively. Using a hypotenuse calculator gives us 748.3mm. Immediately I’m thinking “Yeah this might be too big for me”. When I subtract my RAD of 76cm/760mm from that calculated number (760-748.3) it gives us 11.7mm. This is virtually impossible for me to reach my RAD as I know that adding a stem, slamming it, and adding 0 rise handlebars will put me way over RAD+ with no room to adjust.
A case where this methodology puts my RAD in a safe spot would be to use the Kona Process 134 DL 27.5 at size XS. Its reach being 400 and stack being at 585. Its hypotenuse shows that its 708.7mm, now I’m thinking “hey this might give me some room to adjust my RAD”. So, 760-708.7 gives us 51.3mm. Depending on the situation, I could either get a 50mm stem length, slammed with 0 rise bars, OR a 30mm stem with 10mm riser bars with 10mm stack, OR a 30mm stem slammed with 20mm riser bars, OR a 30mm stem with 0 rise bars with 20mm stack height. The extra 1.3mm is pretty unnoticeable and it will only put me slightly into RAD-.
So basically, size down tailor up is pretty much what I’m tryna say.
The joy of RUclips when you come across a gem like you guys!, great and professional work guys.
🙏
Loving your videos guys. I'm a beginner and this is really helping to inform my purchase choices for a sport with complex geometry. Cheers
This is one of the best videos about bike ergonomics. Subscribed!
I tried your method and my RAD is 873mm (I am 6'2" tall). I then measured my XXL RM Altitude Powerplay and the RAD is 873mm. Win :)
@Flatslide Are you doing your RAD measurement off your knuckle height or how tall you are? I'm 6' 1.5" and my RAD based on how tall I am is 836. I think your RAD measurement based on how tall you are is 840. But my RAD based on my knuckle height is only 800 (I have really long arms) which is considerably less than based on my height. I don't know which measurement to go off.
@@theawesomeone1844 I used the same method shown in the video-with a pencil held in my hand to mark the wall. I purchased my bike 2 years ago based on the fact it was in-store and felt comfortable to ride. I only tried this technique after watching the video to discover my RAD was the same as the bike's. Also my bike has the factory 'bars and stem. There will always be a + or -mm discrepancy :)
@@flatslide3250 thank you for getting back to me. I'm super confused about what size bike to get. Everyone keeps telling me I need an XL or XXL bike, but they feel too long to me. I can't tell if it's because I've been riding the same Med XC bike for the last 15 years and I'm used to a bike that's to small or if a smaller bike really does fit me best. I don't know if I just need to spend time on a bigger bike and get used to it. I'm glad that your bike fits you great! I love my bike but it's stack is only 550mm and the older I get the more uncomfortable it gets.
This method is absolutely spot-on for sizing. I have two frames that are slightly undersized for me that I simply setup to feel right, with a good comfortable lock-in using no measuring at all with stem spacers and riser bars etc. I just checked them against my RAD and they are now near EXACT (
Hmmm thats funny. I calculated reach by the 2.5 formula and got depressed, because i have 35mm to much reach. And with this method, bike fits perfectly, now im happy again 😁🤟 greetings from slovenia
I did the exact same thing with a bike that I have always felt was too long. The height x 2.5 method said it was too long. Then I did that marker measurement and compared to the bike measurement, it said the bike was dead on neutral. Lastly, I did the chairs/stools method and it gave me basically the same result as the height x 2.5 method, the bike is too big! I'm not as happy.... haha
@@cfratify hmmm.. I thought that marker measurement and stool measurememt should give the same results?
⭐️⭐️⭐️⭐️⭐️ It really works. I went from an 80mm stem with seat all the way back, to a 38mm stem seat all the way forward.
It only took 1 ride to adjust to the stem and the seat creaped forward over time.
Wow! I wish that I could DOUBLE SUBSCRIBE to this channel! That is some incredible info! Grabbing my tape measure, shoestring, sharpie, and heading to the garage! Thanks guys!
Thanks Mike! Really appreciate it.
Cool! You found these guys too! I'm loving their stuff!
I recently got a larger bike, and then lengthened the stem on my smaller bike, because the larger bike just seemed to "fit" me better. I just now went out and measured the RAD after watching this video and both bikes measured the same! That's pretty cool!
Way cool!!!!
Heck yeah!!
OK OK! Now, lemme play devil's advocate here: A RAD that matches you means you can generate maximum torque for bunny hops. That's it. It doesn't tell you whether you feel crammed while seated, your hands go numb, whether the bike inspires confidence on steep stuff etc. RAD makes perfect logical sense, but I doubt that it is the holy grail of bike fitting. What are the other possible benefits of going by RAD and what could be drawbacks? Objectively.
Bruh, if you can fully generate Max power and stretch out in a bike, what else can you not do ?
@@liwx what I mean is: That's just one aspect of riding, one motion essentially. It certainly is an important one, but as far as I have understood geometry, it's always a trade off. If a bike is particularly good at climbing, it's not as good at descending, if it's awesome through ruff and steep stuff, it might be less agile etc. So, is there a benefit to long bikes? Because I own one and lemme tell you, it feels amazing.
To me the perfect fit is the one that keep your body weight well balanced between both axles. That depends on the bike geometry. And plus, you can tell how nice is a roomy frame compared to a restricted movement one. However this RAD thing gives you a new and different point of view that’s always a very good thing.
@@HeretiCflow I'm with you on this. It has pros and cons. Bike geometry nowadays are long low and slack for descending. It's for the big gnarly stuff that may question the stability of a shorter bike.
One shortcoming with RAD that I have personally experienced is it doesn’t account for the amount height (stack, spacers, bar) vs length (reach, stem) are in that one number. So, you can hit the same RAD with different lengths or heights (if you use string that has one knotted end held at the middle of the BB, the other knot can be moved in arc up and down all at same RAD number) and those translate to very different setups.
This is amazing. All my bikes have different geo.. reach, bb height, bar height, and I feel really comfortable on all of them but couldn't explain why.... Guess what, they all have identical RAD!!!! Great channel, great vibes, keep going
"Chairs are cheaper than SB150's" 🤣🤣🤣
Is this Lee Mccormack? If it is the Dialed books great our cycle shops use the books now for measurements did for us 5 years ago and we still go by it today amazing info! from UK
"...more like a hunk of meat hurtling to an uncertain fate" Many others have already commented on the best line from this video. It's just too damn good not to repeat again. Instant classic!!
agreed. you're either riding the bike or you're just cargo.
Guys you can't imagine how much i could learn from these 2 videos. Thanks a lot.
Would love to see something in saddle height, fore and aft.
Cut handle bars, shortened stem to improve RAD, hinge saved my quads and hamis today during first family ride of the season. Thank you for the videos and lessons. I finally felt like I fit my bike!
Heck yeah
You guys are messing with my head! I love these videos.
Sorry and you’re welcome?
I'm 6'1 and based on this my RAD would be 83 ish. That would at most put me on a large and even medium on some bikes??? Mind blown.
@@arneilson4450 its crazy, we are the same height and my rad is 87.6. Shows that you can't trust bike charts based on height!
@@MrCharlski I was going by Lee's multiplier. He suggest multiplying height in cm (6'1 is 185.42 cm) by 4.47 = 828.82.
@@arneilson4450 I went with the knuckles to ground measure. I'm 6'1, but my wing span is almost 6'5... I also tried the trick at 8:50 and my bike seems to fit me perfect. I have an IBIS Ripley AF XL with a 31mm stem.
Great follow up from previous video. I consciously not paid too much attention to the previous one as I had just bought a new back and didn't want to be missing oartnof the joy of a new bike by figuring out that I took the wrong choice. Truth is that I am always between brand sizes, an usually go for a size smaller. The new Focus Sam2 geometry is a bit different than my Scott Ransom but not too much. I downsized in the Ransom to an M (178cm tall) despite lots of people telling me that I should take an L, and could not be happier. Feels just the right size. When I sat down in a size L, the Focus seemed massive, but as soon as I tried size M I new it was my bike. It just felt right for me. I measured today thr RAD in both bikes out of curiosity and guess what, both where spot on (the Sam2 is 1cm longer) with my meaure! I really think this works. By the way, do let me know if you plan to jump to Spain in your trip to Europe. We have many Brits that come around to MTB. Much nicer weather... ;)
Love it when a plan comes together. Spain would be amazing!!!
Hi! Great video. Thanks for enlightening us all. One thing puzzled me, though... At 3:42 you mention that the target frame reach is based on a 40mm stem. Since most XC bike stems are at least 60mm long, does it mean that I should/could deduct 20mm from the target frame reach when looking for a XC bike with a 60mm stem? Thanks again and greeting from Rio de Janeiro, Brazil!
What’s thinking the same. Unfortunately no answer.
I would like to thak you so much for what you are doing!
I had a thought that my bike not exactly matches me. So I messed with different stems and bars trying to fix that, but really had no idea what am I doing. I thought I got too low bars or too long reach or whatever. What I was doing is actually trying to fit the bike for a taller person than me. And it did not work, obviously. And I probably would never figured out what am I doing wrong if not you guys!
After watching a couple of your videos (especially this one) and making some measurements and checking my bike geometry numbers I found out that my bike fits me just perfectly! So after some calculations and measuremens it turned out the only thing I needed to do is to remove all the spacers from under the stem. This setup has shortened the RAD and suddenly it felt like magic! 200% fit, like the bike was made exactly for me. It feels totally different like it became extension of my body! I was literally shocked by how it felt. I never thought what a big difference can be made by those little spacers.
This is the best explaination of bike sizing I have ever seen, that is for sure. After watching a bunch of your videos it suddenly clicks in my head and I understood like everything: bike geometry, reach, stack, why so much different stems and bars, why there are spacers, etc. Now I am not only happy with my bike which turned out to be perfect for me, but I know exactly how and why to set it up. Like of course I do not need any spacers: the frame does the perfect match already and adding up spacers is fitting for a taller person whoes match to the frame is not that perfect. Totally makes sence. No more unconscious tunings and random set up. 😌
Thank you!
I was super relieved to find that using this measurement, my new bike is perfectly RAD, but I’m struggling with understanding how this applies to those with extreme ape index. If I have abnormally long arms, would not my RAD be much shorter than what my bike should be?
I’d assume not, as the RAD defines the exact measurement regarding perfect bike fit. If anything I’d say that this measurement supersedes the ape measurement.
I think what you’re saying is a valid point, but I’d assume that your arms would have to be down past your knees (exaggeration) to warrant any concern with a way shorter bike. I suppose people with extreme proportions (really long arms / really short legs, vice versa) other considerations would have to be made.
I.e, if you had a really short RAD No, that indicated a Medium frame, but had really long legs that only suited a Large frame, for example, then I’d assume you’d have to buy a Large and use a shorter stem / use bars with a higher degree of back sweep to ensure you hit RAD.
"abnormally long arms" puts your hands closer to your feet. ... the point is to size your bike around you, and that length. If the bike feels smaller under you, then it will also be more playful, nimble, and smaller body movements / body english will be necessary
exactly what I was thinking
Are you standing pedal length apart with knees straight or bent?
Huge THANK YOU for this video, and your other ones about geometry and bar width!
I'm one of probably many people who bought a size L following the brand's size chart (Giant Reign 29), when after all I should have trusted my gut and bought an M size. It felt "large" from the start, but not CRAZY oversized, also it was my first "modern" geo enduro bike after a long hiatus (I'm 37 yo), and i DID want a long / slack bike that induced some confidence, so I ended up keeping the L bike and thought I just have to get used to it.
Little over a year later, I DID get used to it better, but it always felt huge, sluggish, and not perfectly at home, especially compared to my 20yo allmountain fully with ancient geo that is WAY smaller.
So i started checking prices for used frames in size M, but no luck - instead i found YOUR VIDS! And after some measurements i figured my RAD on the bike was a good 6 cm over what it should be ideally...
Long story short: I ended up cutting my 800mil bar by 20mm (HUGE difference!), turned it a little further back to reduce upsweep, and dropped 10mm of spacers below the stem. Result: I'm now within 2,5 cm of my of my "ideal RAD", and the bike feels WAY more nimble, agile and properly sized! I'm considering swapping to a shorter stem, which would bring me dead on my RAD, but i feel that might even be too much. Bike as it is now feels already SO much better and more the way i want it to feel, it's crazy! Manuals / Wheelies are still not easy, as obviously my wheel distance didn't change, but at least now i can ATTEMPT them, and it feels like something I can train towards, instead of feeling just insecure and lacking power.
THANK YOU!
Any thoughts on how leg length vs torso length effect sizing? Short legs=shorter chain stays and longer top tube?
+1 to this!
I have a long torso and kind of short legs and demo'd a few bikes before I bought my latest (unfortunately too long, but that's COVID supply chain for ya... glad to have anything). The description of bike geo trends is I think not the full story re: root cause... steeper seat angles and slacker HA get the rider more forward which IMO really helps with traction on descents even if you haven't been coached on riding position (I think these 2 guys don't buy that, but with the front wheel more forward you've got a longer lever arm). On the climbs, with steeper SA, your rear end doesn't shift back as much when your dropper is extended. Seems to me you can get away with a smaller bike now without the front wheel unweighting on step ascents, which is an issue I had 6 years ago on a slack SA medium (I was in between sizes). During my pre-COVID demos, I universally enjoyed climbing bikes with steeper SA. I guess this would matter more for people with long legs and short torsos. You can compare estimated top tube and reach between bike models... the ETT number was a pretty good indicator of seated roominess (mediums seem to range from ~580mm [my OG TR Patrol] to 615mm [Revel Rail]) and reach of standing room. I know stack height matters too but it helps to gauge how it'll feel when, especially now, it's really hard to get a leg over a demo bike.
Seems to contradict RAD. I have short legs and long torso/arms, so my RAD is shorter than it would be for a normal person of my height (my arms are closer to the ground). But I actually have a greater range of motion due to having longer arms!! So I should be on a larger, not shorter bike, contradicting RAD. There is also the matter of my body’s center of mass being more forward than a regular person, so this also suggests a longer reach is needed to prevent the OTB feeling when descending.
@@technovelodos
Ummm.... I have long legs, short body and long arms, now I'm really confused 🤔
Good to know we are all so different tho, 😂
@@totalcranker I think my comment only applies to the method of holding a pencil and drawing line on the wall. There are other ways to measure your RAD and they may work better for our body type. Having said that, I measured my my bike and my RAD using this method and my RAD was only 2cm shorter than the bike's RAD (M frame and 172cm tall) so we're talking small differences either way.
First time that I agree with a way to measure a modern mountain bike. Thanks. Good job guys!
Our pleasure!
This works a lot better than the height based formula as it takes arm length into account. This also explains why my bike is so comfortable despite the published reach of 475mm being at RAD+ for me using the arm measurement forumla, with my bars and spacers I'm at 465, right in the middle of my RAD sweet spot, the height based reach would have me at 445
I don't know how the knuckle height RAD takes into account arm lenght. If anything it ignores it. I'm 6' 1.5" which gives me a RAD based on my height of 836, but my RAD based on my knuckle height is 800, the same as Alex, who, I believe he said he is 5' 9". Based on my knuckle height Alex and I should be on the same size bike, but if he is 5' 9" his RAD based on how tall he is, is 783. For having the same knuckle height RAD of 800, our RAD based on how tall we are is different by 53 mm.
Easy to follow video. My new bike felt a little short to me, it measured 79cm and I needed 82cm. Swapped the stem and handlebars now have 83cm which feels a whole lot nicer, there is still some adjustment to bring it back if needed. The wider handlebars I put on made a big difference too, the whole thing feels right now.
I love this video. Couldn't say more about how much this has opened my eyes to bike fit issues and given me possible explanations for why my bike probably isn't for me (even though I pass the lay down test).
However, I do think the fitting methodology here should be improved to account for rider proportions. I'm a tall rider at 6'5", and most of my height is in legs. Even with getting the rad right, I think most bikes' stack/reach ratio, is too small for my disproportionately long legs, so I end up with my torso more parallel to the ground, and my weight all over the place forward/aft. I either have tons of weight on my hands and my head in front of the bars, or my ass is above the rear axel.
For reference, I have a Ripley V4 XL which is 500 reach, 631 stack, and a 1.26 stack/reach ratio. I haven't had a chance to ride anything else recently since there are no demos, but my hunch is that something with a ratio above 1.30, and a reach around 490 (which ironically is what Lee's height in cm * 2.50 = reach equation spits out for me) will be better. Need to do the actual rad measurement though, so this hunch is kind of uninformed at the moment.
I just suspect that if you don't account for this, on the average bike (or my Ripley anyways) either your long arms make you stand too tall putting your weight too high, or your long legs put your butt in the air and make you too bent over unable to keep your weight between the axels (rad remaining equal in both cases).
Really the question is "is there an optimal torso angle over the bike?" Then with arm, torso, and leg measurements you could REALLY dial in fit.
Both these R.A.D instructional videos made the most sense I've ever seen in measuring for a bike. Thank you, love your content
How to get RAD using geometry charts. You can get pretty close using a right triangle calculator. Pythagorean theorem, Insert stack and reach into the calculator. This will be short cause it does not take into account headset and bars on stack measurement. Guys what would be a good "average" measurement to add to stack?? Example Nukeproof Scout I added 9cm for headset and bars from website info, 73 squared (stack+9cm) + 45 squared (reach) = 85.75cm. My RAD barefoot is 85! so pretty good! I understand that if you add to the stack it will decrease the reach because the head tube is on an angle so you can knock off a couple cm if you want this should get you pretty close. Thanks for the info, subscribed!!
Great job it worked for me too! 2021 Norco Range VLT Medium stack (602+90)^2 + reach (450)^2 = C^2 = 825mm. I measured it and got the same number. Easy to punch in the reach and stack on a pythagorean theorem calculator online and I added 70mm to stack for spacer height plus 20mm for handlebar rise.
Thanks, very cool. It got me right in the ball park.
As someone right on the line between sizes I totally would have bought a size too big had it not been for this video.
Thanks for the save?
Freakin A bros. I’m gonna use Alex’ RAD measuring method in every bike shop I visit 😂
OMG. That would be legendary!!!!
Thank you! Amazing info! I've been struggling against the mainstream fitment ideology. But your perspective 100% validates my real life experience with how my body feels when riding. I don't need to be all stretched out to "get maximum pedaling power".
Glad it was helpful!
Hi, Lee!
Thank you very much for the book ‘Dialed’, it is very helpful.
I have a question though. Is RAD and RAAD measurements are performed with sagged bike or not? I’ve found this moment crucial for hardtails.
Thank you!
Your bottom bracket to bar distance shouldn't change regardless of sag...
@@waveblaster146 but it does. Shorter fork = longer reach
@@amdmg7 No, not when it comes to RAD, but okay.
This makes more sense - many thanks. Since the last video I have been trying to do something like this. Maybe I'll be the "Guy" lying on my back trying the quick hack option when unable to measure!
Maybe someday it will be normal!! : )
Great videos, love watching them. Just a question about the bike/body position at the core of the RAD fit theory. When you measure, eg 4.48 and 9.12, the feet are flat but when actually riding and executing that move Alex ( and probably all riders) are up on the balls of their feet eg 7.37. For me that extends the measurement by 30mm. Is this relevant ?
Nice catch!
I have been fine-tuning things like saddle height to great effect. Just for the goof I discovered my body's RAD is 77cm, and my bike is 75.6. I knew it felt good, and nice to see the numbers support it.
OK, OK, you win, I'm buying myself a pair of platform shoes tomorrow (no need for a new smaller bike).
Hahahaha. That'll work!!!
I'm 5ft 8 and I just got a brand new NS Bikes define AL in small for £1230. I've always ridden a medium frame but got this to flip because it was such a good deal. Looks like it may not be leaving my shed now 😁👍
Steep seat tube angles aren't to create more clearance for the rear wheel, suspension, etc. The reason is to shift the rider's weight forward for better weight distribution when climbing. This is why you'll see bikes built to ride up steep mountain terrain with 77-78 degree STAs and bikes built for XC with 75-76 degree STAs.
Took the advice, and at 5ft 7in, I bought a small Trek Slash, as even the small has a 425mm reach!
I came from a medium Scott Spark in comparison, and at 440mm reach, it also has a 60mm stem.
The small Slash has 15mm less in reach and 25mm less in stem length, and my RAD is fairly spot on - result on the trail is I don't feel like I'm leaning on the bars anymore...
A discussion with Christ Porter (Mojo Rising) & Leo (Pole Bikes) would be very interesting since they seem to preach the opposite ;)
I think that Lee is more interested in preaching for fit and skills improvement but those folks are just looking at all out speed.
Ahh this will be fun when I finally ride with my two geometron owning buddies again - to them he really is Christ!
Glad you followed up with this after the last video. Going off of height is certainly inaccurate. For instance, I'm slightly over 6 foot 2 with my shoes on but I have long legs and average arms for my height. This lengthens my rad number. However, there are a few other variables here. Most people position their pedals towards the front third of their feet which causes them to leverage through the balls of their feet with their heels up which extends their rad number. Also, the position of your hands while leveraging is typically 2 or 3 inches in front of your thighs which also would increase your rad number. I would suggest measuring your rad with your heels slightly up and your hands two or 3 inches in front of your thighs.
That was rad guys🤣
Your channel is my favourite YT channel, better than GMBN. Even thought they're great too. I followed your instructions and surprisingly my bike as it is setup is at my RAD number. I'm blown away. I'm 186cm and the bike is a Large Norco Fluid HT1. The manufacturer recommends I use an XL frame.
maybe I can put that shirt in the store soon.
Thank you ! But can you explain what with people with longer or shorter arms ? Does it mean that with longer arms I should get smaller bike? and opposite, with shorter arms bigger bike would fit better ?
Curious about this also...as a long armed human...
No reply on this question yet? Long armed freaky people are still waiting.
No. They should get a bike that fits their RAD measurement. Regardless of how long their arms are
So fun!... today I was changing the flip ship on my bike, steertube spacers, and the stem on my bike for a shorter one (because Im selling my expensive Burgtec one to make money...), so, I literally spent all my day trying to think on all my previous bikes reach+stem+bars combos, doing calculations, checking videos about cockpit setup and effects, etc... and boom!!, after I saw your video, I wrote my body RAD and my bike RAD and it's my perfect RAD jajajajja... Thanks guys that's my years of testing in 3 minutes >< jajaj
I would totally lie on my back to size a bike at a demo. That would be one of the least embarrassing things I've ever done in public. Thanks for this video though! It turns out I've been riding rad double minus (ridiculously small) on my hardtail down chunky black trails. For this reason I was convinced a Large Revel Rascal was going to be too big for me. Turns out it's not. Medium will be rad minus. Large could be rad plus OR rad neutral. BTW I'm only 179cm but that really does put me on a Medium or Large Rascal (still Medium on other brands though) I just M and Large yesterday and they both feel amazing. I really am right in the middle. Going to demo some again and will re-measure. My ideal would be rad neutral for this bike.
I need to hang out with you!! We do a demo crawl in Sedona making a scene.
Love this vid!
As a road bike fitter I always suggest going down a size for the same reasons you do. I’m amazed manufacturers recommend up sizing!
Here’s a thought: It appears that the RAD measurement on the bike (bottom bracket to middle of handlebars) is somewhat close to the 3rd side of the triangle made up of the stack and the reach. So could Pythagorean’s theorem be used to approximate the RAD measurement? For example:
RAD = √((stack2)+(reach2)); the 2s are supposed to be square subscripts
So a bike with a reach of 450 and stack of 612 would have an approximate RAD of 760. Then perhaps add another 5mm or so to that to reach the invisible line, approx. 765.
Yes, absolutely. This is what I've suggested too. You have just add another 100 mm to compensate for the cockpit which includes head post, stem, handlebars raise and so on.
@@mishkathebear This is an older video so don't know if I'll get an answer but would you really add 100 mm instead of 10 mm? 10 centimetres sounds like a lot :D contemplating between two bike sizes..
@@irisvesamaki7665 Im no expert on this, but you will definitely need to add a couple of centimeters. On my hardtail which has 70mm stem a 20mm spacer I had to add round 100mm (10cm)
Handlebar: 9-degree backsweep, 15mm rise, 31.8mm; 740mm width
wish i new this before i purchased my bike! bought a medium for me a small for the mrs, (same bikes) i have always felt better on her small. now i know why!
I looked thru the comments and couldn't find this question and since there are 753 of them I'm just going to ask it... If two people are the same height but one person has a longer reach than the other (longer arms), the person with the longer reach would have a smaller RAD than the other and may need a smaller bike although they have a longer reach. Am I wrong? Please correct me if I am.
Good question. I would also like to know this.
By logic presented in this clip, yes.
cementary, please explain
@@spritle1700 I mean, if you follow the only one measurement presented in this video, then yes. Longer arms&same height means smaller bike. Crazy isn't it?
Yes crazy. Reach needs to be factored into the equation before this can be considered a viable way of fitting a body to a bike imo.