3:55 Yeah I have a flexible BB on my bike, it's the square tapered BB that came with it... I can literally see it flexing from side to side when applying force lol
THANK YOU! Great episode. After a near 25-year hiatus, I started mountain biking again. (Didn’t realize how much I’d missed it. Loving it.) As you can imagine, A LOT has changed; including terms used, varying types of MTBs, components, and more. This episode has provided me with clarity needed.
How about a video about different suspension linkages. Does the shock placement have any real difference? For example Canyon Neuron 2019, AL vs CF. AL has bottom mounted shock, CF has top tube mounted.
This is the video I needed. I am still riding an old DiamondBack Sorrento from around 2003, old school, so know I have an idea on replacement! Now for frame size for my 6'1" and 33 inch inseam. Note, I have monkey arms, I always need 34/35 arms in dress shirts.
17:47 so actually when 29" started it was only 26 existing which usually had around 1.5inch=38mm fork offset. 29 usually had around 2inch=51mm fork offset. so then came 27.5 to split the difference in the middle and it usually had around 1.75inch=44mm fork offset.
The seat tube angle has little to nothing to do with taking weight off your hands. That's literally nothing more than where the seat is located in relation to the handlebar & wheels. Rather, the seat tube angle affects how the location of the saddle changes _as you adjust the height of the seatpost_ .
I've been waiting for a comprehensive video like this for so long. Thank you gmbn tech! I love the quick bike anatomy explanation at the beginning. Perfect video to send to friends when they ask about what effects certain measurements have, half the time I never even know myself haha.
I don't know how you make me listen to such a boring subject so intently. You have helped me as a beginner rider with so many of your videos, you and your team. Thank you! I ride a 2015 Diamondback SYNC'R with a 4" bar rise built up an old proflex 96 with a 1x10 as well as a 4"bar rise and I even got the wife out there with me an a 2018 GT aggressor with new hydraulic breaks bar riser pedals upgraded rotors mig shift 1x7 which when I get the money will become a 1x10 and I learned almost all I needed through this channel!! Thanks guys and ride on!
I still prefer to measure the bike by going by the length of the top tube not by the reach. When I am sitting it is supposed to be comfortable and while I am standing I am supposed to be agile and move around.
@@smalerider1727 I agree as well. It was a bit of a disservice of him to say ETT isn't really important. I feel it's more important than reach. Especially with these steep seat tube angle bikes, if they don't make the reach absolutely huge by old standards, the bike is way too short. It's all preferences and how you ride, but I ride in the saddle probably 80% of the time. It's hard to argue I should size the bike for only 20% of my ride, but that's the going advice these days...
Probably reach is more important for enduro/DH riders where you car about descending and not really on the seat pedaling... I kind of agree about ETT or TT measurement thought... it is probably the first impression if the bike is small or large. Stack is a good one! I never knew I loved a large stack just makes you feel more like in a BMX to me. Shame you are pedal strike prone
True, but you can adjust the seated length of the bike with Saddle adjustment, offset seapost and stem length but the standing reach (ie weight distribution between the wheels when standing) is set by the geometry.
Thanks for this video, great and simple explanation about different parts of geometry, there's not that many good vids like this out there so definitely something that was needed.
I came to your channel to search for orientation regarding a vintage bike called the Cannondale M800 Beast of the East. The Beast’s frame has a sloping top tube, a high bottom bracket and a very short seat tube. I guess that the next step is actually riding in one. I come from a Cannondale M400 which has a traditional top tube, with minor sloping. Later I purchased a used AMP Research B4 bike and upgraded the rear damper with Risse air and oil unit. But I never evolved to more expensive and modern bikes and long for this M800. Thanks for the clarification of the elements of the bike!
If you count the welds as gussets then it could be considered a double blunt ended shallow cut diamond frame. Still, these guys are very entertaining and informative. I wouldn't have looked it up had they not made the mistake :)
OK - I think I figured it out by connecting the dots. You get 5 points on the side view of a "Double Diamond"frame - front and rear hubs, headtube junction, BB, and the seattube-toptube-seatstay junction. The 1st diamond is the one we see clearly in metal - seatstays > toptube >downtube > chainstays. The SECOND diamond in the "double-diamond" construction includes one line that doesn't exist in metal, but is critical to modern geometry. It goes like this: seattube > toptube > FORK LEGS > "missing link". So there's the forward-leaning obvious frame diamond, and a second rear-leaning diamond with a missing bottom line that connects the front hub and BB. What? Ok so - imagine a Penny Farthing. Huge front wheel, tiny back wheel, and no chain - the pedals are mounted directly to the front hub. You can't draw that second diamond because there's only 4 total points. Later than the penny farthing you got bikes with equal wheel sizes, but still pedals directly on the front hub - no double diamond. It was only when someone moved the pedals out with the chain drive that we got the 5th point to connect and the modern bicycle. That invisible bottom line in the 2nd diamond is what makes bikes work the way it does, with stable rear for smooth power application and power disconnected from leading-wheel steering = nimble, controllable turns.
They should provide a range of numbers for each key geometry spec, and describe how those ranges change between riding style (XC, Trail, etc) and frame size (S, M, L, ...).
Make a video about fitting the mountain bike for really tall riders. In some countries it's not easy to find frames bigger than 21", which is not enough for guys >2m tall. There's no video like that on YT, so it will be great to hear some tips how to make 21" bike feels comfortable. PS. Another great video. Great job guys 💪
Great video. I'm 60 and was riding a Norco Sasquatch back in the early 80s and touring and mountain biking since then. Do I say this to pontificate with my superior knowledge about bike geometry? Not at all! Until this video I have basically been a geometry illiterate and ibnorance has been bliss. I remember putting a suspension fork on a late 90s rigid Cannondale CAAD 600 back in the early 2000s and the LBS guy telling me it would change the bike geometry. I thought "WTF are you jabbering about?!?!" Even with upgrading bikes over the years I just thought this was mumbo jumbo and happily went flying over my handlebars thinking this was expected. Finally, started to clue in it all wasn't just propaganda a couple years ago when I bought a drop bar mountain/adventure bike (Salsa Fargo) that could alternate between fixed fork and suspension with specific specs. This video would have helped me in cobbling together the rudimentary understanding I now have of bike geometry. Any young whippersnappers out there that are poo-pooing this knowledge, listen to the man.
Some manufacturers like Trek, sometimes list geometry at 30% sag for full-suspension bikes. That makes sense, because on hardtail head angle steepens when you start pedalling in normal position, and on full-suspension it actually slackens. So why doesn't every manufacturer provide that info?
Not that any of these measurements wouldn't make a difference to different riding disciplines, but how long ago did manufacture start advertising the engineers notes??? Seems like a mind boggling amount of different things to keep track of vs what your realistically thinking of when one would buy a new or used offroad motorcycle. In any case, I always appreciate a rather diligent effort to make info like this digestible. Top notch content!
Just getting back in to cycling.... just found this ENGLISH channel .... FANTASTIC !.... really helpful info. really easy to understand , great presentation THANK YOU ... I just subscribed !
8:52 serious question: when measuring the effective seat tube angle, doesn't it depend how high the top of the seat post is? therefore I'm guessing there must be a standard such as it being level with the top of the head tube?
Most bike company measure their STA with a horizontal line from top of head tube to center of post. That's why if you have long legs you need to be aware of the ACTUAL STA as well. It could be way different from the Effective STA.
I am old school. I had a Z1 on a GT LTS Carbon and it was slow responding. Almost chopper like. I moved to a hard tail GT Xizang with a much shorter shock which gave me the best ride. It climbed like a goat just a little small for me so I got a custom fit Seven Cycles Sola. and put a Marzoch Marathon on it 2000 era. But it is still with me, it climbs really really well, it went down as good. But the primary ride was about an hour climb then about 2 hour down so the climb comfort up front was important for enjoyment of the ride.
I had a Schwinn Homegrown, climbed nicely but was it was nervous on the downhill. Also have a Turner Flux that did'nt climb as well bus was fast on the downhill.
Thanks. That was awesome. Clear explanations of what the measurements are and how they affect the bike. Was always confused about what exactly offset and trail were.
Nice accurate info my dude!!!!! Yeap, and let me just say that trail angles can change how a bike feels almost more than a frame being a little too long or short. When I raced BMX I had an XL frame, but ran with a fork that had the axle at the bottom centre of the fork tubes, not in front. So I had better stability in the frame with quick steering! Got me a trophy at Bexhill back in the day! 😎
Great video that takes some of the myths and headaches out of all the number crunching you seem to have to be able to do before committing to a certain size bike. Perfectly explained, great stuff!!
Bravo! I've long wondered about most of this, and wasn't even aware of some of it. Fascinating stuff. And as others have said, an explanation of differences in suspension design would be most welcome too. Thanks for pulling this together.
Best geometry analysis I've seen on the web. However, stack is absolutely critical for XC. High bars suck for climbing, especially on 29ers where you're already higher above the ground. It's taken manufacturers too long to figure this out.
So as head angles get slacker the wheelbase gets larger, which then make the bike longer for handling in switchbacks. Especially when climbing and riding technical stuff. And I agree with the comment that although reach is important, a long virtual top tube may not be comfortable on longer rides. We don’t only do technical riding...
15:21. The chainstay length shown is wrong. It's actually the distance from the rear axle (including dropout) to the center of the BB. *It's not the horizontal length as shown* Edit: And again. The front center is not just the horizontal measurement. It is the distance from the BB to the front axle (including dropout).
Extremely detailed video, but in my opinion, still one often neglected but important element is missing which affects not only to comfort, but to stability and (should be) to drive setup: the Q-factor.
Good stuff.like changing wheel sizes.i 26 and 20 and 24...no plans on bigger ..but I know which geometry this life has 20000 on it..im settled in.so I convert to next size wheel
Awesome video with important information! Try to do a video for building a new bike from scratch. How to choose the right combination of components according to the measurements of your bike, like crank size, Chainline or the Offset, Suspension travel and Installation height for forks etc. Things that someone has to keep in mind, before buy components and other stuff for his bike. Things that are vital for the stability and geometry. For example when I bought my "unknown" MTB frame from China, it came with the plan of the frame and its measurements. So I had to search a lot on the internet, for information about all the parts of the bike, and then choose the right ones. The thing is that RUclips is full with videos of "how to replace this", "how to maintain that", but not with videos of how to choose the right fork, crankset and other things, especially when you don't have the old component to compare with.
The thing that bugged me for so many years is how mountain bikes were sized. I grew up riding BMX and still ride BMX. Since the late 80s BMX bikes have always been sized by length, not height. When I started mountain biking in the late 80's I gave up on it right away because the bikes rode so terribly. Short top tubes and long stems. Then I got back into it around 94 or so. I got a Kona and the first thing I did was put rise bars on it and a shorter stem. That bike was the longest top tube I could find in my size. But it wasn't until the early 2000s that I was able to get an On One Inbred in 16" with a 23 inch top tube. I put a 50mm stem on it and loved that bike! But bikes were still measured by seat tube length......all the way through the 2000s. DJ bikes were an exception, but not regular mountain bikes. I just never understood how it could possibly take bicycle companies so long to understand that a bike should be sized by length and not seat tube height. It took a VERY long time to get the road bike mentality out of the mountain bike industry. Those of us who came from a BMX background knew different all along. A full size BMX bike starts a PRO (usually 20.5" top tube), PRO XL (21" top tube) PRO XXL (21.5" top tube) and so on. Due to how high bars are on BMX bikes, 8, 9 or even 10 inches high, the top tube length seems a lot shorter but it's not. Most BMX bikes do measure by actual top tube length and really they should measure by effective top tube length. Since the top tubes are almost always close to the same angle between frames it's not as big of a deal. This is how BMX bikes have been sized for decades.
Nice video and very informativ, I´m a XC rider, but is good to know that kind of information!!......I love your show, keep up like this and please include more videos and info about XC bikes and races!!!!.....(I`m a big fan of your show)
You'll know it the first time you try to do a tech climb if your reach is too long, the front end will come up quite quickly unless you're really leaning on the front (the too long reach effectively takes weight off the front). If your reach is too short, your knees will smack the bars during tight turns.
Doddy great segment. You spoke about muscle useage briefly with the seat angle. I’m thinking there could be a segment on muscle useage, injury, and setting the bike up to compensate or fit a rider carrying a semi-permanent or permanent injury better e.g. lower back, knee or shoulder. Thanks Jezza.
Fantastic , Layman's explanation for what really seems complicated till watching this , although I am going to have to watch this about 20 times to take it all in. 10/10 on this one Dodsters . What I would like to watch now is put a trail bike beside an All mountain or cross country and physically show the difference and why as well as you did in this video. You can skip the gravel bike unless Martyn wants todo it . HaHaHa . I think he's an anti gravel bike guy.
![Felix "Unfair" | [Stray Kids : SKZ-PLAYER]](http://i.ytimg.com/vi/Oswujxm2Ag0/mqdefault.jpg)
19 minutes about geometry. Doddy and the team have outdone themselves!
Awesome!
Was it useful for you?
Absolutely useful. Added to my RUclips Favorites short list.
Yes!!!! I'm off to buy a new bike tomorrow, so it was
.brilliant to receive this important information
Beforehand !! THANKS GUYS!!! 😀
I feel so privileged that the Dodster has taken time out of his hair modelling career to explain MTB geometry to us!
I really am LAUGHING OUT LOUD
And imagine David Schwimmer is there with him.
His hair is as stiff as a porn stars micky.
top tube? you probably meant nutcracker.
lol
Hell yes
@@Shpektrometer and God help those with large undercarriage
LOL
I actually saw a bicycle brand called nutcracker and it had that written on the top tube :D
3:55 Yeah I have a flexible BB on my bike, it's the square tapered BB that came with it...
I can literally see it flexing from side to side when applying force lol
THANK YOU! Great episode. After a near 25-year hiatus, I started mountain biking again. (Didn’t realize how much I’d missed it. Loving it.) As you can imagine, A LOT has changed; including terms used, varying types of MTBs, components, and more. This episode has provided me with clarity needed.
How about a video about different suspension linkages. Does the shock placement have any real difference?
For example Canyon Neuron 2019, AL vs CF. AL has bottom mounted shock, CF has top tube mounted.
This please!!
Horst four-point or four-bar rear suspension. Look up Turner bikes.
Merida/Centurion LRS and GT I-drive also was some interesting cookies.
Would be nice to see one retrospective about various soft-tails too.
Yeah that would be really cool. DW Link-Horst-VPP-all the other fun stuff out there. So many cool options these days...
Hi guys how about 26ers frame with 27.5 front fork and 27.5 wheel set?
Absolute hero of an episode. We've all been waiting ever since that ask GMBN ep a few months ago
Best geometry explain ever!!
Now I need a vid explaining all the different types of suspension linkage and how they behave (VPP, DW, DELTA, etc)
This is the video I needed. I am still riding an old DiamondBack Sorrento from around 2003, old school, so know I have an idea on replacement! Now for frame size for my 6'1" and 33 inch inseam. Note, I have monkey arms, I always need 34/35 arms in dress shirts.
17:47 so actually when 29" started it was only 26 existing which usually had around 1.5inch=38mm fork offset. 29 usually had around 2inch=51mm fork offset. so then came 27.5 to split the difference in the middle and it usually had around 1.75inch=44mm fork offset.
The seat tube angle has little to nothing to do with taking weight off your hands. That's literally nothing more than where the seat is located in relation to the handlebar & wheels. Rather, the seat tube angle affects how the location of the saddle changes _as you adjust the height of the seatpost_ .
I've been waiting for a comprehensive video like this for so long. Thank you gmbn tech! I love the quick bike anatomy explanation at the beginning. Perfect video to send to friends when they ask about what effects certain measurements have, half the time I never even know myself haha.
Really help full video thank you for explaining the confusing nomenclature easily.
You have made it so much easier for me to understand the dynamics that go into my bike. Thank you for the great information!
I don't know how you make me listen to such a boring subject so intently. You have helped me as a beginner rider with so many of your videos, you and your team. Thank you! I ride a 2015 Diamondback SYNC'R with a 4" bar rise built up an old proflex 96 with a 1x10 as well as a 4"bar rise and I even got the wife out there with me an a 2018 GT aggressor with new hydraulic breaks bar riser pedals upgraded rotors mig shift 1x7 which when I get the money will become a 1x10 and I learned almost all I needed through this channel!!
Thanks guys and ride on!
I still prefer to measure the bike by going by the length of the top tube not by the reach. When I am sitting it is supposed to be comfortable and while I am standing I am supposed to be agile and move around.
Pillokun I agree, but our opinion about geo might be seen as antiquated
@ Ride Alongside How do you pedal a bike? EET is very much relevant and should be the first measurement considered.
@@smalerider1727 I agree as well. It was a bit of a disservice of him to say ETT isn't really important. I feel it's more important than reach. Especially with these steep seat tube angle bikes, if they don't make the reach absolutely huge by old standards, the bike is way too short. It's all preferences and how you ride, but I ride in the saddle probably 80% of the time. It's hard to argue I should size the bike for only 20% of my ride, but that's the going advice these days...
Probably reach is more important for enduro/DH riders where you car about descending and not really on the seat pedaling... I kind of agree about ETT or TT measurement thought... it is probably the first impression if the bike is small or large. Stack is a good one! I never knew I loved a large stack just makes you feel more like in a BMX to me. Shame you are pedal strike prone
True, but you can adjust the seated length of the bike with Saddle adjustment, offset seapost and stem length but the standing reach (ie weight distribution between the wheels when standing) is set by the geometry.
Finally a step by step explanation. Most appreciated
Thanks for this video, great and simple explanation about different parts of geometry, there's not that many good vids like this out there so definitely something that was needed.
super informative and very clearly presented, big thumbs up!
I came to your channel to search for orientation regarding a vintage bike called the Cannondale M800 Beast of the East. The Beast’s frame has a sloping top tube, a high bottom bracket and a very short seat tube. I guess that the next step is actually riding in one. I come from a Cannondale M400 which has a traditional top tube, with minor sloping. Later I purchased a used AMP Research B4 bike and upgraded the rear damper with Risse air and oil unit. But I never evolved to more expensive and modern bikes and long for this M800. Thanks for the clarification of the elements of the bike!
You are a good teacher, I have learned more on bike than I have learnt my whole life, thanks you
I've been waiting for this video without knowing it! Really helpful to know the anticipated handling changes with changes in geometry.
It's just diamond frame... there's one diamond. There are two triangles though.
🤣
Yip yip yip yip, uhuh, uhuh.
If you count the welds as gussets then it could be considered a double blunt ended shallow cut diamond frame. Still, these guys are very entertaining and informative. I wouldn't have looked it up had they not made the mistake :)
OK - I think I figured it out by connecting the dots. You get 5 points on the side view of a "Double Diamond"frame - front and rear hubs, headtube junction, BB, and the seattube-toptube-seatstay junction.
The 1st diamond is the one we see clearly in metal - seatstays > toptube >downtube > chainstays.
The SECOND diamond in the "double-diamond" construction includes one line that doesn't exist in metal, but is critical to modern geometry. It goes like this: seattube > toptube > FORK LEGS > "missing link".
So there's the forward-leaning obvious frame diamond, and a second rear-leaning diamond with a missing bottom line that connects the front hub and BB. What? Ok so - imagine a Penny Farthing. Huge front wheel, tiny back wheel, and no chain - the pedals are mounted directly to the front hub. You can't draw that second diamond because there's only 4 total points. Later than the penny farthing you got bikes with equal wheel sizes, but still pedals directly on the front hub - no double diamond. It was only when someone moved the pedals out with the chain drive that we got the 5th point to connect and the modern bicycle. That invisible bottom line in the 2nd diamond is what makes bikes work the way it does, with stable rear for smooth power application and power disconnected from leading-wheel steering = nimble, controllable turns.
Not good when somebody wants to teach us about geometry, but does not know the difference between a triangle and a diamond. :-(
Probably one of if not the most helpful MTB vids I’ve seen. Keep up the great work guys!
Great video Doddy. Been biking for over 35 years and I can honestly say I learned a couple things. Well done sir
Knowledge is a weapon.
GMBN..🙌
They should provide a range of numbers for each key geometry spec, and describe how those ranges change between riding style (XC, Trail, etc) and frame size (S, M, L, ...).
Make a video about fitting the mountain bike for really tall riders. In some countries it's not easy to find frames bigger than 21", which is not enough for guys >2m tall. There's no video like that on YT, so it will be great to hear some tips how to make 21" bike feels comfortable.
PS. Another great video. Great job guys 💪
I knew all this, but it really made me think about how hard it is to end up with the perfect combination.
This is really helpful, thanks. I paused a lot and took notes. About to buy a new bike and the jargon blows my mind.
This was so helpful, I wondered what all these terms were and how to apply it to riding, now I can. Good speaker too.
I’ve been riding for over 30 years and l’ve learnt so much. Thanks. Brill explanation
This is outstanding, guys!
Top quality video, thank you!
Great video. I'm 60 and was riding a Norco Sasquatch back in the early 80s and touring and mountain biking since then. Do I say this to pontificate with my superior knowledge about bike geometry? Not at all! Until this video I have basically been a geometry illiterate and ibnorance has been bliss. I remember putting a suspension fork on a late 90s rigid Cannondale CAAD 600 back in the early 2000s and the LBS guy telling me it would change the bike geometry. I thought "WTF are you jabbering about?!?!" Even with upgrading bikes over the years I just thought this was mumbo jumbo and happily went flying over my handlebars thinking this was expected. Finally, started to clue in it all wasn't just propaganda a couple years ago when I bought a drop bar mountain/adventure bike (Salsa Fargo) that could alternate between fixed fork and suspension with specific specs. This video would have helped me in cobbling together the rudimentary understanding I now have of bike geometry. Any young whippersnappers out there that are poo-pooing this knowledge, listen to the man.
Thanks for this, very informative, I have not measured myself up for a bike since the early 90's and things appear to have changed!
Some manufacturers like Trek, sometimes list geometry at 30% sag for full-suspension bikes. That makes sense, because on hardtail head angle steepens when you start pedalling in normal position, and on full-suspension it actually slackens. So why doesn't every manufacturer provide that info?
Not that any of these measurements wouldn't make a difference to different riding disciplines, but how long ago did manufacture start advertising the engineers notes??? Seems like a mind boggling amount of different things to keep track of vs what your realistically thinking of when one would buy a new or used offroad motorcycle. In any case, I always appreciate a rather diligent effort to make info like this digestible. Top notch content!
GMBN has risen to the top of online MTB publications - just exceptional! Thanks!!
Brilliant explanation of mtb geometry, the best I've seen.
Thank you.
Great video Doddy! Looking forward to the up coming info.
This is a FANTASTIC video! I learned SO MUCH! thank you for making it!
I really like the presenter, very clear and concise
Just getting back in to cycling.... just found this ENGLISH channel .... FANTASTIC !.... really helpful info. really easy to understand , great presentation THANK YOU ... I just subscribed !
Great to hear Carl!
This is the greatest informational mountain biking video ever made.
8:52 serious question: when measuring the effective seat tube angle, doesn't it depend how high the top of the seat post is? therefore I'm guessing there must be a standard such as it being level with the top of the head tube?
You are correct and as far as I know there is no sound standart for measuting esa.
Most bike company measure their STA with a horizontal line from top of head tube to center of post. That's why if you have long legs you need to be aware of the ACTUAL STA as well. It could be way different from the Effective STA.
I am old school. I had a Z1 on a GT LTS Carbon and it was slow responding. Almost chopper like. I moved to a hard tail GT Xizang with a much shorter shock which gave me the best ride. It climbed like a goat just a little small for me so I got a custom fit Seven Cycles Sola. and put a Marzoch Marathon on it 2000 era. But it is still with me, it climbs really really well, it went down as good. But the primary ride was about an hour climb then about 2 hour down so the climb comfort up front was important for enjoyment of the ride.
I had a Schwinn Homegrown, climbed nicely but was it was nervous on the downhill. Also have a Turner Flux that did'nt climb as well bus was fast on the downhill.
Thanks. That was awesome. Clear explanations of what the measurements are and how they affect the bike. Was always confused about what exactly offset and trail were.
We have an explanation of Low vs. High trail with relation to road and gravel bikes. ruclips.net/video/L0Kt-c8fG3M/видео.html
Nice accurate info my dude!!!!! Yeap, and let me just say that trail angles can change how a bike feels almost more than a frame being a little too long or short. When I raced BMX I had an XL frame, but ran with a fork that had the axle at the bottom centre of the fork tubes, not in front. So I had better stability in the frame with quick steering! Got me a trophy at Bexhill back in the day! 😎
Brilliant video. One of the most helpful I've found for mountain bikes.
Great video that takes some of the myths and headaches out of all the number crunching you seem to have to be able to do before committing to a certain size bike. Perfectly explained, great stuff!!
Fantastic video, very helpful. Thank you!
Excellent 101 start video with explanations! Provided new information for my understanding of current designs. Thank You!
Very informative. Thx, Doddy!
As a carpenter, that has never got to use that laser level Christmas gift - I finally have a use for it 😬
Bravo! I've long wondered about most of this, and wasn't even aware of some of it. Fascinating stuff. And as others have said, an explanation of differences in suspension design would be most welcome too. Thanks for pulling this together.
My 2008 Scott Genius has a nice high BB, especially when I threw a 160mm fork on it... I love its ride now
Clear simple vid doddy, great job. Clear graphics, well done to the doodler with white pen!
Very comprehensive Doddy, nice one.
Best geometry analysis I've seen on the web. However, stack is absolutely critical for XC. High bars suck for climbing, especially on 29ers where you're already higher above the ground. It's taken manufacturers too long to figure this out.
So as head angles get slacker the wheelbase gets larger, which then make the bike longer for handling in switchbacks. Especially when climbing and riding technical stuff.
And I agree with the comment that although reach is important, a long virtual top tube may not be comfortable on longer rides. We don’t only do technical riding...
15:21. The chainstay length shown is wrong. It's actually the distance from the rear axle (including dropout) to the center of the BB.
*It's not the horizontal length as shown*
Edit: And again. The front center is not just the horizontal measurement. It is the distance from the BB to the front axle (including dropout).
0:59 Actually, sloping top tubes came about to reduce different frame sizes and instead, utilise long seat posts.
Extremely detailed video, but in my opinion, still one often neglected but important element is missing which affects not only to comfort, but to stability and (should be) to drive setup: the Q-factor.
Very informative. Thanks!
Good stuff.like changing wheel sizes.i 26 and 20 and 24...no plans on bigger ..but I know which geometry this life has 20000 on it..im settled in.so I convert to next size wheel
Awesome video with important information! Try to do a video for building a new bike from scratch. How to choose the right combination of components according to the measurements of your bike, like crank size, Chainline or the Offset, Suspension travel and Installation height for forks etc. Things that someone has to keep in mind, before buy components and other stuff for his bike. Things that are vital for the stability and geometry.
For example when I bought my "unknown" MTB frame from China, it came with the plan of the frame and its measurements. So I had to search a lot on the internet, for information about all the parts of the bike, and then choose the right ones.
The thing is that RUclips is full with videos of "how to replace this", "how to maintain that", but not with videos of how to choose the right fork, crankset and other things, especially when you don't have the old component to compare with.
The thing that bugged me for so many years is how mountain bikes were sized. I grew up riding BMX and still ride BMX. Since the late 80s BMX bikes have always been sized by length, not height.
When I started mountain biking in the late 80's I gave up on it right away because the bikes rode so terribly. Short top tubes and long stems. Then I got back into it around 94 or so. I got a Kona and the first thing I did was put rise bars on it and a shorter stem. That bike was the longest top tube I could find in my size. But it wasn't until the early 2000s that I was able to get an On One Inbred in 16" with a 23 inch top tube. I put a 50mm stem on it and loved that bike! But bikes were still measured by seat tube length......all the way through the 2000s. DJ bikes were an exception, but not regular mountain bikes.
I just never understood how it could possibly take bicycle companies so long to understand that a bike should be sized by length and not seat tube height. It took a VERY long time to get the road bike mentality out of the mountain bike industry. Those of us who came from a BMX background knew different all along.
A full size BMX bike starts a PRO (usually 20.5" top tube), PRO XL (21" top tube) PRO XXL (21.5" top tube) and so on. Due to how high bars are on BMX bikes, 8, 9 or even 10 inches high, the top tube length seems a lot shorter but it's not. Most BMX bikes do measure by actual top tube length and really they should measure by effective top tube length. Since the top tubes are almost always close to the same angle between frames it's not as big of a deal. This is how BMX bikes have been sized for decades.
Great video and information, Doddy! Of course, I’ll need to watch it a few times to let it sink in. 👌
This is truly excellent. I feel like Neo from the matrix when he finally realised there is no spoon!! 🥄
That's true because for half the viewers on this channel there is no bike
Thank you - excellent explanation, so clear and easy to follow.
Thanks, Doddy, that was the best intro to geometry I've seen. Bookmarked.
Very insightful and informative video. Thank you
Nice video and very informativ, I´m a XC rider, but is good to know that kind of information!!......I love your show, keep up like this and please include more videos and info about XC bikes and races!!!!.....(I`m a big fan of your show)
Excellent explanation. Thank you.👍
Glad you liked it!
I am into stingray chopper models as i feel they are important because for general people such a frame is ideal
Great work Doddy. Finally I have a bit of an idea what the geometry of a bike is. Thanks.
Really helpful video. Thing's became clear🎉
You'll know it the first time you try to do a tech climb if your reach is too long, the front end will come up quite quickly unless you're really leaning on the front (the too long reach effectively takes weight off the front). If your reach is too short, your knees will smack the bars during tight turns.
I am just now getting into mountain biking. Very informational.
Great to hear Daniel :)
How do you know what reach is right for you when deciding on a frame size??
you guys should make a video of the different kind of angles and what angles are for different types of mtb
Great informative video - well explained. Thanks
Superb Video .. Thanks a ton ..
Thank you! Easy to understand and good information.
Great info and great way to show measurements. Helps alot when looking at a new bike for sizing or ordering a bike online. Thanks
My new favorite video.. Well done folks..
I waited so long for a video like that! Now i finally understand what it could mean if you talk about some measurements in a bike check...
Doddy great segment. You spoke about muscle useage briefly with the seat angle. I’m thinking there could be a segment on muscle useage, injury, and setting the bike up to compensate or fit a rider carrying a semi-permanent or permanent injury better e.g. lower back, knee or shoulder. Thanks Jezza.
VERY GOOOD!!! Thumps up!
this channel is so amazing, thx guys!!
love that park tool set up behind you! thanks for the vids!
GREAT info here ! Dod you rock !
love this..Answered alot of question about modern geometry
Thank you Sir for this very informative video.
smartest guy on gmbn...maybe youtube...maybe the world!
1:36 in Norway we call it ramme lengde(frame length) which makes sense I guess.
Phenomenal video! Thanks!
Excellent video, cheers mate. 👍🏻
Fantastic , Layman's explanation for what really seems complicated till watching this , although I am going to have to watch this about 20 times to take it all in. 10/10 on this one Dodsters . What I would like to watch now is put a trail bike beside an All mountain or cross country and physically show the difference and why as well as you did in this video. You can skip the gravel bike unless Martyn wants todo it . HaHaHa . I think he's an anti gravel bike guy.