Seems like for most of us, the subjective feeling matters more than numbers. Personally I love the snazzy acceleration feeling of the mid (28 but measured 30mm on my rims) when going uphill. Love these comparisons! Thanks a lot!
I have just moved from 30mm to 34mm Vittoria Corsa Pro - I completed the Peaks Challenge here in Aus last weekend and given the condition of the roads - I am sure they assisted me!
That's what I ride on the crappy UK roads. I'm using 50mm deep gravel rims that sit almost flush with the side of the tire. It's about as bomb-proof as you can get for a road orientated wheel without going gravel tire
@@gild5942it’s hard to feel the difference the extra 60g of weight makes. To test the effect on your own bike, add 60ml to a drink bottle and ride uphilll. Then remove the 60ml and ride up the same hill. See if you feel faster. The power difference to travel at the same speed is less than 0.1W
At the end of 2022, I retired my racing bike (23mm tires) and bought a new endurance bike (30mm tires). I thought Id have to change them out for 26mm to stay competitive with my buds who all have racing bikes with 25-26mm tires. But after riding for a year+, I am riding faster than I ever have. Please do me a favor and stop making these tire videos before my buds catch on to my secret!! P.S. Love the tumbleweed segment.
Watch the video.. but rolling resistance at the optimal pressure is lower for the wider tire. That is why the chart shows the largest variation at slower speeds where rolling resistance matters more than the air resistance as a percentage of total drag. Once you are going faster as seen in the 300 watt chart the tires are the same because tire differences are a smaller than air resistance at high speeds. Air drag increases at the Square of speed.. @@Religion-Geschichte-eh7hm
Same here. I changed from 25s to a 32 and my times & watts were relatively the same. What did change was my endurance on long rides. The 32s gave me an additional 30km spot on.
I sure hope you guys (GCN) can keep going with the loss of the network going away . That really sucked. We all loved your channel GCN+ here in the states. Such a great amount of well thought out content and great people!!!
Im using the 35mm Continental GP5000 All season tyres. They arent cheap but worth every penny. So much comfort and almost no speedloss. Loving these tyres especially in the rainy seasons.
@ttospp kuuurwa!! sounds amazing! Enjoy 😍.. i live in the netherlands, i only ride my bike to work atm, weather is awfull indeed haha but i bet its freezing out there in poland now haha
My new bike came with 25s on modern carbon wheels, and when I upgraded to 32s, it was like I had a whole new bike - loads of PRs on the first ride, felt so much smoother, and the control around potholes etc. was just better. Thank you for showing us the science in videos like this that helped me take the leap!
Several comments in one (for no extra cost): 1. Great video, great discussion, nice little tumbleweed.. 2. It's taken a while for the bike manufacturers to offer road bikes - race & endurance - with enough tyre clearance to allow up to 35mm 3. If those tyres are all effectively the same performance, on the same rims, then the 35mm will offer even more with wider rims (say 31mm internal) 4. The 35mm tyres will be as much as 100 grams (2 x 50) heavier than the 26mm tyres. 5. the 35mm tyres, especially for tubeless, will be easier to mount & unmount on/from the rims 6. no-one ever discusses the possibility of using different widths front & rear, despite known wind profiles for such (as in TT bikes). I use Vittoria Corsa 28mm (measure 30mm @ 75psi) on front & VC 30mm (measure 32mm @ 75psi) rear on my Cannondale Synapse. I'm 81kg. Terrific balance, performance & wear. Upgrading to 2x 35mm....
Nicely done! Really like that you kept it to a single variable as much as possible, and had a variable-checking final run. That graph really tells the story. Kudos! Thanks for running the exact test I’ve been looking for!
Absolutely love this content! Love the gcn does science videos! Well done you two. The results surprised me because of the surface. I started going for more width after reading Rene Herse's myth busting articles. While riding the Northumberland Hills (Ontario) I was amazed that my 40mm Schwalbes (which are tanks with stiff sidewalls) made my normal gravel routes much faster. Fast forward to today, I run 44mm Snoqualme Pass Rene Herse on my touriing bike, 40cm Schwalbe Marathon Supremes on my stepthrough citybike, and 35's on my exercise bike. The most comfortable and fastest are the 44's. Like you, when I moved up in width I noticed the difference in handling, but I like how the Touring Bike trails. Thank you so much for this surprising and interesting content! Well done! More please.
I went from 25s to 32s in 2007, when I got a frame that would fit them. It was non disc frame, so had to let air out to put it past the caliper brake, but ran a disc fork, so no worries up front. A few years later, got a new frameset & went to 35s. I wanted even larger, but had to put adjustable dropout all the way back to get 40s in there, which made the bike handling more like a touring bike, so last year had a titanium frame made that could fit my desired road tire, the Rene Herse 44 Snoqualmie Passes (measures 42.5mm on my rims). Best decision I ever made. Might seem like overkill, but the country roads I love to ride on, they're perfect. I even went this winter without putting on my winter wheelset with 42mm knobbies, which will now be relegated to offroad use only.
Doing a new bike build this year and will make sure the frame can take 35’s. Currently limited to 25mm on my 2015 frame. Most of my riding is rough roads so can’t wait for the change.
I also have a cx bike as do-it-all, as in N+1=1. There seems to be some variability in the geometry of cx frames though. I've seen quite aggresive geometries out there, but for example mine is actually more like an endurance road bike, even though it's the brand's cx entry level frame. They even tag it as endurance in their website lol. I can run up to 40mm on it, but am also limited by mudguard clearance in the winter.
I had a giant tcx that had kinda cross specific geometry with the higher bottom bracket. With road slicks it was exactly the same speed on the road as a road bike.
I run a set of @Reneherse 48mm tires and have zero problems keeping pace with the group I ride with. Bonus, I'm less fatigued at the end of our 100km rides.
Happy to hear I’m not alone! My Topstone has RH 48 on front, 44 in back (as wide as will fit) and in informal rolling tests they roll no slower than the next guy on his 28s. Some caveats though: at that width (and corresponding low pressure) they do get “bouncy” when pedaling hard, both sprinting and climbing. And a bigger tire is heavier for sure, so perhaps not the fastest to get going. Finally the pneumatic trail change is real; I will likely go back to 44 in front on my next tire change to make the steering a bit snappier. (On the other hand, 48s on 650Bs on the same bike are downright playful)
Currently riding Vittoria N.EXT 28s at 60 PSI. Thinking about switching back to ENVE SES 29s and dropping 5 PSI. I like the tyres for the level of puncture resistance. Love your coverage as well, Paul.
I'm thinking the same. The way I was struggling to keep up with a mate riding road tires on my 650b - 1.9" gravel tires, I'm definitely thinking there is a turning point, but seeing 35mm do this well, it's probably at a wider width than I'm guessing.
It depends on the surface in all reality and the context of the effort. Thus it is always a "it depends". For TT specialists it is a much more thorny question because they are actually working both parts of the "CdA" variable directly...a few Watts can be the difference between a win and 2nd. With modern rims the Cd part of CdA is better management but the A still exists...it always exists. Thus it comes down to "what solution best matches the course and tactics requires".
Great video. Jan Heine figured out-and proved-this apparent paradox a decade ago. Si, you said you’re reluctant to go with 35s on your Pinarello, but try a pair of Rene Herse 35s and you’ll never ride anything else.
It's not really a paradox; the science has always said wider tires have a rolling resistance advantage. The paradox is really why the bike/tire manufacturers have denied it for so long.
@@nowthenad3286 The area of the contact patch the tire makes with the ground is a function of (weight over tire) / (PSI of tire) = (square inches of contact patch). For example, 100 pounds over one wheel / 90 psi = 1.11 sq-inches. This relationship is largely glossed over in most people's high school physics class which is why most people aren't familiar with it, but if you ever see a method to imprecisely measure the weight of a vehicle by measuring tire contacts and tire psi or hear advice about letting air out when stuck in snow/sand or why semi trucks need 100+ psi whereas cars are designed for 30 psi, this relationship is why. In our bike example, that 1.11 sq-inches takes the form of an ellipse with the width of that ellipse dictated by the width of the tire. Comparing the patch between 2 tires, a wider tire has a wider contact patch over a narrower tire. That also means a wider tire has a shorter contact patch than the narrower tire, given the same contact area. A tire makes a contact patch longer by deforming it's shape, it squishes in. A longer contact patch of a narrower tire means the tire has to deform more than a shorter contact patch. Tire deformation is where the majority of rolling resistance comes from; having to constantly re-squish new spots of the tire as it rolls along a flat surface is what robs a tire of it's motion energy.
My cyclocross super commuter came with 32 mm cyclocross tires, which are soft, do not last long on the road and I kept getting flats. By me being a road cyclist, I decided to switched over to 35 mm heavy duty anti-puncture protection road tires, installed tire liners inside the tires and slime sealant in each inner tube for additional puncture protection. I must say due to the additional weight of everything, I am not able to travel as fast as previously, but the ride is more comfortable and I am no longer concerned about getting flats. I have absolutely no regrets in doing so.
Great point by Simon @ 10:00 that before wider tyres mostly seemed to be tank tyres, super heavy puncture resistant types and now so many great options in wider sizes.
Except for Rene Herse (formerly Compass) Jan Heine was onto this wide road tire thing YEARS before the rest of the industry, and he's been making great, supple, wide road tires for a long time.
Never going back below 32mm, and I am here for trying out 35-38mm. I am a casual biker on a road bike, worn pavement with some cracks, 5% gravel, 5-10% smooth surface. Why do suffer with
Road bike is for good surface. Gravel, dirt road, cracked pavements? Buy a nice MTB as a second bike. Really wide tires, 1,3 bar in front, 1,5 rear and you may go over deep sand as well
@@exucontongood advice but speaking for myself, I’ve never liked flat bars unless I’m handling some really gnarly terrain. The gravel bike revolution has served me well! I can ride just as fast on smooth roads as before (notwithstanding my advancing age), but I can also ride in scree and gravel with no issues or discomfort. Once I start having to deal with roots and big rocks, I know I’ve lost my way.
Well... i cant really tell when climbing. It is slow. Im on a gravel bike a bit heavier than the old road bike, but gearing is lower... so up is easy. Not sure it is faster or slower. Going so slow it is not bumpy anyway. But down really bumpy roads is waaaaaay faster with slack gravel geo and chubby rubber. I will also say that i did a 135km ride with 2800m climbing with about 10km on a gravel road with these tires. Better than the guy i was with who walked hos 26mm tires the entire way. We kept pace everywhere e cept the steepest parts with me on gravel bike and him on wiggle carbon road bike with skinny tires. He did outpace me on a couple steep hills... but i think only because hos lowest option was 34:30, and mine was 30:36, so i could go up slower... he HAD to go up faster, or walk
I have 38mm slicks on my gravel bike for commuting (SCHWALBE PRO ONE TUBELESS ROAD TYRES). They were the widest I could find. So comfortable and no noticeable loss of speed over the 25mms on my road bike.
Just made the change from 23mm conti's to 28 goodyear eagles it does help. Honestly, as my bike is a 30+ year old steel relic, I reckon tyres are probably 90% of the difference with modern machinery that and about 3kg in the frame 😂 ... but that just trains the motor harder! 😉
I bought a new bike last year so that I could accommodate 35mm tyres and I'm glad manufacturers are producing lighter tyres in those widths now. I didn't even know you could get a Pirelli Pzero that wide until this video. I can't believe I once ran Michelin 19 in another life. I love riding bigger tyres at lower pressures
What was the velocity vs watts for a given tire size? Time to distance is meaningless since there's huge variability in the line taken / distance traveled around the track. Also, a torque transducer at the front wheel is the only valid way to determine rolling resistance.
Amazed how consistent your results were for all the variables you would have in that kind of test ...spent 30 years in the tire industry,... to measure what you were trying to demonstrate we would have done in a controlled indoor environment on a test drum with various grits to determine friction coefficient. As a recreational and Club cyclists for many years I have transition from 26 to 30 on the road bike with no loss of speed but more comfort!
It would be interesting to consider many aspects that relate to a complete ride and how to test for those aspects, the: - amount of difference friction / aero related energy, compared to the distance travelled in order to show the differential - variation of contact patch dimensions for the same rider weight, for different width rims - some sort of roll down test - typical and potential maximum gain related to surface roughness, versus mass when climbing - sprinting / cornering loss for width Perhaps there is a Goldilocks point related to cyclist weight, tyre pressure, and tyre size. Bigger isn't better, smaller isn't better (especially in all circumstances) - so maybe a zone of generalization depending on usage. For sure whilst as a teen I used to enjoy my 19's on perfectly smooth cycle tracks, apart from them shaking your eyeballs - pot hole flats, and wet manhole covers could be treacherous. Understanding ride speed and when each variable becomes a key factor would be all consuming.
@@barrylewis8916 I'm definitely with you and you totally nailed the factors to be considered! In general you couldn't say either one size direction is better, but for most riders even not hitting the sweet(est) spot some could really argue to better step one size up than one down. Might be that 32C for (mostly smooth) road use is the limit in size up... Might be that 35C for (smooth to rough) road use is the limit in size up... Might be that 45C for (mostly smooth) gravel use is the limit in size up... Might be that 50C for (smooth to rough) gravel use is the limit in size up... It would be much appreciated if someone can do the circumstance dependend analysis. From this a data set could be created and then very most riders could easily look for their ideal tires when entering their data (weight, surface, climbing ambitions versus distance ratio). Zero Friction Cycling for example, did this with lubricants and from now on it's as easy to select the one of choice regarding the cicumstances of riding and needs (enviroment, costs, friction). KUDOs for any effort to this kind of direction!
Wow, so many comments, I'll be surprised if you can read them all! I live in the mountains (Asheville, NC) and our "typical" ride has 1000 ft of climbing per 10 miles. Weight is an issue for us. There will always be a compromise on weight with bigger tires. Also, I still run tubes (!!!), so going w/lower pressure (to a certain point) is always going to be a risk of pinch flats. So much to consider...
Don't get your argument with getting more pinch flats when lowering the pressure on an existing tire or a different/wider tire. If you go too low, you give up speed and risk damage to your rims (and tubes). On MTBs you can get an snake bike flat. For sure, wider tires are heavier. In contrast you get a comfortabler ride and let you put more power to bring on the ground therefor. Don't break your head, just because the weenies discuss the general sweet spot shifting. ;-) If you're unsure, take a tire size up, as most users are getting more comfortable with.
Watching for second time. Excellent video. 35mm - 1(3/8)" in old money, now, when do I remember that from? It took me ten years to move from 27*1(1/4)" Weinmann concave rims with Weinmann 500 brakes to dual pivot Shimano 105 (the greatest game changer in cycling history of the last 40+ years) to 1(1/8)" to 700C Mavic MA40 with 25mm then 23mm tyres. Said before, best ride ever was 120 miles in rough lanes of North Downs Kent on 2007 Cannondale System6 Ultegra, Mavic Ksyrium Elite wheels with 23C Vittoria Diamante Pro tyres at 160 psi that lasted just 300 miles, as reviews said. More affordable tyres, nowhere near as nice a ride. Age 69, I get the return to fatter tyres. 10 mins in: the quality of the fat tyres is what is the big thing. Back in the day, bomb proof commuting or cycling for work meetings all over London: Nutrak Nomads, then Schwalbe or similar fatter tyres with horribly hard treads were slower and less comfortable than narrow quality tyres. Big mistake was buying used Roubaix Elite in 2018 with 25C tyres. If I could, I'd order wider rim tyres to take 32mm+ tyres today. But I can't afford £600 to £1k for wheels, tyres, tubes. Ideally, I'd change the bike to aluminium and clearance for quality wheels and 35mm tyres. Also, amused by attitude to rim brakes. Shimano 105 on aluminium rims in 1980s gave all the stopping power and control in any conditions that anyone ever needs. But... it also wore down the rims, which could be expensive so, despite the more complex maintenance of disc brakes, I think I prefer disk brakes, especially when the rims get wider. V-brakes on wide tyre road bike (eg first generation Tricross after the recall of the dreadful caliper brakes) never had the precision of Shimano 105
I still ride 23mm tubulars. Would love to see how they compare on that surface, not that I will be changing. For the riding I do now (leisure) cannot see the point in buying new wheels even if it means going tubeless. I am old and I like tubs!
22mm tubular I use as match rim width, love as stay on with flat front at 42mph downhill I hate going should I upgrade hub and spokes so maybe 870 or less or save to build Trek Emonda ALR to 7.3kg (computer, lights, bell on bike, with pedals)
I’m a fat tire guy. 30 - 32’s for my road bike, 38 - 42’s (42 is the biggest that’ll reasonably fit). Last time i rode 25’s was in a race. Roads were not great and as soon as I got home, I took them off and threw them away to remove the temptation of ever riding 25’s agin.
Just bought gp5k 30s. Haven’t ridden them yet. I’ve been riding 28s for several seasons. Maybe I should have gone all the way to 32s great video. Very interesting
Nice to see DRIVE wheels on GCN. The 50D and 65D were my favorite wheelsets for ~2 years until other brands started to coming out with wider external AND internal wheelsets for a similar price. Hard to beat the 50D for price to weight ratio.
Heck yeah, I’ve got 38s on mine and even in Tokyo there’s some rougher bitumen on some of the routes I take & comfort is so different between my 28s & 38s
Got my first road bike in 2018 and also started watching you to learn something. Right away got the feeling that wider tires are the way to go and always used the widest tire my frame and rim brakes could manage. Two years ago I got disc brake bike and am running 35c since and I'm never looking back.
Recently switched to 30s from 28s (both GP5000, on 21mm internal rim width wheels). Definitely feels smoother, and no perceptible downsides. Moving fron 25s to 28s (still GP50000) was an even bigger jump. You brace yourself for a patch of dodgy tarmac and just sort of glide over it - that's the best bit.
If it fits (that's what she said), put 32C at the rear. Material difference between 30 and 32 in comfort yet again. And at the rear you have zero aero penalty. Also means you don't worry about sketchy surfaces anymore.
Put the widest tires your bike will accommodate is the rule of thumb. You're already paying the aero penalty (if there is one) with the width of the fork and rear triangle so you might as well be as comfortable as possible.
21c rims means it's already a gravel/monstercross bike? I have them on my specialized AWOL, mostly do tarmac and i've fitted some slick 55mm tyres which are great, but just because of not having to worry about frame clearance, i'll eventually switch back to 35mm. They're best compromise imho, always depending on one's riding needs of course. No need to push tyre size to the frame's limit and them risk rubbing, be it one far day in the future, but still...
Running 32mm GP5000 S-TR tires at 3.5 bar on Zipp 303 Firecrest wheels on my road optimized gravel bike. Smooth and grippy. Being a gravel bike, I could go to 45mm but that's reserved for off road activities. I do run the widest tires I can on my road bikes but I'm limited by frame clearance. 25mm on my 2011 Trek Madone and 28mm on my 2019 Trek Madone SLR. Both are rim brake.
I just swiched from a 28mm to a 30mm in the rear on my road bike and even though my condition and FTP is at a low point i already did some PR's which surprised me a lot...
You guys did what you could to keep everything equal except rim width. The "rule of 105" (rim width should be at least 105% of tire width) means there will be aero losses running a wider tire on the same rims. The test also doesn't measure rider fatigue which will increase with narrower tires at a higher pressure over longer rides so even if a few watts are lost to aero the effects of vibration from narrower tires will probably sap some watts from the rider.
They kept the wattage constant so rider fatigue doesn't factor into the equation. And if the rule of 105 applied then surely the wider tyre would have been slower - what you're essentially saying is that the wider tyre should have been even faster than it was!
@@RH-nk7eo I also think that applying the 105 rule, the wider tire with adapted wider rims would be slightly even more faster. Especially because the wider rims can be of equal weight or added weight will be outperformed of aero benefit. If the (wider) rim would fit the (wider) tires more properly, it seams to gain more of the aerodynamic effect than the loss due to being more heavy. I'm also with the argument of Surestick88, that the additional fatigue of narrower tires that will be added to the (for sure constant 100 W) power transfered, will slower the narrower tires in the long rong. In my opinion the 35C tire would be best compromise of weight (for climbing and acceleration), frontal area (for aerodynamic), comfort (for fatigue resistance) and rolling resistance (for smooth tarmac to rough roads/bike paths)! Some may find their sweet spot at 32Cs or 28Cs front and 32C back; and might step up in the more future. ;-) That said, looking forward to get my hands on the (currently not available) Pirelli P Zero Race TLR 35-622 to be mounted on the Light Bicycle WG44 rims (30 mm inner dimension, 38/40 outer dimension).🤩
I've used my Trek Domane with 35c Schwalbe G-One All round on paved and gravel roads and have managed close to 30km/h at one point. I was only slowed down by street signs and Red lights Not a show of strength but rather something that supports GCN in this video
@@johnandrews3568 you can still buy 19s if you really want them🥴 No idea why anyone would want them. I won't even run anything under 25 on a velodrome anymore
@johnandrews3568 can't share links on RUclips anymore. But look at 700cx19 wheelchair racing tires. They're interchangeable and most wheelchair racers just use conti 5000s anyway. No idea why you'd want slow tires though😂
I raced against local sprinting Strava segments on a “fitness bike” with 36” Schwalbe tires and I broke many records. As I started loving to ride the bike I then bought myself a proper racing bike. Now I m riding on 25 because I like the road feel.
I've been running 32mm at 70psi for a couple of years now. In truth, it was only last year that I dropped the pressure. I mainly ride on Suffolk country roads, and on these tyres, the ride is so much more comfortable than my previous 28mm (21mm before that!). Great work guys 🙂
I have been using 30's and recently moved to 32's. More than just the speed, if one is riding for few hours, the overall comfort you get from a larger tire over the longer period is just nice.
My Scott Solace 20 eRide came with 700 X 38c. A size I had never ridden before on a road bike. Most of my past bikes have had 32 or less. For me, I could feel a huge difference. The Solace 20 is such a smooth ride. Now, I'm not racing it but when I pick up the pace in group rides, it performs perfectly. But the huge advantage is on uneven roads. That 38 at 60 PSI smooths out the bumps.
Well BicycleRollingResistance did this test like 5 years ago, and this is exactly what they found out. At the same pressure, the wider tyre is faster. But at the same comfort level (or as they measured it - the deformation/tyre drop under the same weight) the results were pretty much identical in rolling resistance.
Yes and therefore his conclusion in this particular article was: take the narrowest tyres possible that meet your comfort requirements (not bottoming out and not risking pinch flat). Wider than necessary is just adding dead weight.
I read an interesting comment that back when racers were running relatively springy steel frames, the narrow high pressure (tubulars) were still pretty great. As the industry has pushed us to stiffer, harsher frames and forks, wider tires at lower pressures are more obviously helpful.
Steel frames being comfier is another cycling myth. Now marketing BS with the 'Steel is real'crowd. Cycling About took frames into a lab to test. Tyre pressures have always made the biggest difference to comfort, with way behind that long flex seatposts and frame deflection being a non event.
For me, the really important aspect of this is that the "suspension" you get from tyres is in another league compared to any kind of structural compliance from frame material. There's a reason why mountain bikers are running bigger tyres than they used to even though suspension has improved leaps and bounds at the same time. Cheers, Si
Kona Libre CR gravel bike. OEM: WTB rims with WTB Venture 47 x 650b tires. For "road rides", DTSwiss CR-1600 rims with Teravail Rampart 38 x 700c tires. Both sets run tubeless.
I used to have 25mms on my old vintage motobecane from the 80s. Now i use a cyclocross bike as my all-in-one bike with 33mm tires. The extra grip and comfort, especially in rainy and wet conditions with random branches strewn on the road give me confidence to actually go faster, and bike more often when i might have stayed inside or taken the bus. There's just no contest between the two for me, 33mm or thereabouts any day
Same here. My CX is my road bike too and I stopped going to my summer 28mm road tyres after realizing my 5mm wider CX tyres were as fast. With more comfort and grip too. Win, win.
You have less grip on wider tyres in the rain. Why? These tires have a smaller contact patch and can cut through standing water more effectively, reducing the risk of hydroplaning. So you’d better off using the 25mms.
@9:35 -- there have been fast, wide, supple tires for decades. I was riding Grand Bois 700x30 back in 2007. They just barely fit my road frame but, anecdotally, my fastest rides back then were on those tires.
@@InfiltrateIndustriesNope my 28 continental 5000-TL measured 1.2mm wider on my 20mm internal rims than the 5000S-TR that replaced them. It was like 30.2 for the 28mm 5000-TL and 29mm for the 5000S-TR. The continental 4000s were even wider than the 5000-TL. So manufactures downsized their tires a little bit, to make the difference between the labeled width and the actual width a bit smaller.
But which tyre width was more fun to ride? I got excited by all these revelations about wide tyres and went up from 25mm to 28mm on my road bike (same tyre make/model, recommended pressures, modern carbon rims optimised for 25 or 28s) and was surprised that the ride was noticeably more dull and lifeless with the wider tyres. For me, the most important thing is that riding my bike is fun. After a couple of long rides to give them a good try, I gave the 28s away and I'm back on 25s and loving them. (For context, I'm 62kg and have been riding road bikes and cycle commuting on a daily basis for the past 20+ years.)
I’m about your weight, and have not regretted for one second replacing my 25 mm for 28 mm a couple a years ago. I would like to treat 30 mm if my frames allow it.
Agreed, I've always thought 25's gave all the comfort I need. And I've no intention of going to tyres that are wide enough to ride ver potholes without noticing them...
Fun equates to a jarring ride and less grip and speed on descents? You have questionable intelligence. Also, wider tyres are faster on real world roads because of less vibration.
I have actually ran both the standard and the extra light. The sidewalls do weep a little at first but sealed and the standard set up easy tubeless with zero issues. I don’t ride anything super chunky so I have never worried about going with the endurance casing. The standard is still extremely supple, compared to other tubeless road tires I have ran and I feel are very worth it. I am a big fan of Rene Herse tires! These are my road set up on Enve rims and feel every bit as fast as the 28’s I was running
@timtuckett723 Which model are you running? Did you have problems mounting the extralights and how was your experience with punctures on those? Thanks!
As a heavy rider, I’m encouraged by these results🙏 but my beloved 2006 Specialized Roubaix comp will barely accommodate a true 28c. That aside, I’d love to know how each tire size perform (handle) on climbs and down hills with turns? I’d imagine there are performance differences?
This is a good idea. The reason is the weight distribution when riding ( more weight on the rear wheel). You can use nearly the same tire pressure. The slighty smaller tire at the front wheel improves the speed at fast descents. On my 2 wheelsets I use 25/28 and 30/32 (for long rides).
It has been done quite often in time trialling and triathlon, where a narrower tyre on the front gives better aerodynamics and a wider tyre on the rear gives more comfort and reduced rolling resistance. In the back, aerodynamics and frontal surface area are less relevant. Also mentioned by @dirkstaudt4341, the weight distribution plays a role. However, on road bikes the distribution is generally about 52% on the rear and 48% on the front. You can't use the same pressure if you're running for instance a 25/28 combination.
I have 32mm road tires/wheels on my CX bike that I routinely swap out in place of the gravel tires and they feel faster than my road bike wheels 25mm! Thanks for doing the research on this topic! ❤
They're all the same - what a surprise! The biggest resistance is air resistance and 80% or so of that comes from the rider - so at constant watts the results are bound to be the same. Of course tyre widths and pressures have an impact - narrower and higher pressures on the track and wider and lower pressure on bad surfaces or in the rain. They have an impact but it's second order compared to the aero drag from the rider. But the idea that changing from 23 to 32 was going to turn us all into MvdP or TP was always marketing bluff that was for the birds.
@@Dr-bob1337 not necessarily. I'm under the impression that there's been a much more scientific approach to everything related to cycling in the past 2 decades, from gear to physiology. Big teams and big brands are spending big money on research. Probably in the past it wasn't as easy because the technology to do the research wasn't there yet or was too expensive for what could be gained. It was easier to find ways to get away with doping.
No-one ever claimed fatter tyres would get us rainbow jerseys. The claim has always been more grip and comfort with no loss of speed. The more comfort will however keep you going faster for longer because being rattled is fatiguing.
snoogled 32mm front and 30mm back into my old giant wich is supposed to have max 28mm. Biggest difference I noticed was in corner-speed and confidence while descending.
Great video Lads. In engineering we were taught more surface area contact the more power required to move an object, and there are formulas to calculate this. Less contact, less power required to move an object. So I've been watching all the videos regarding tire widths thinking how is this possible🤔 😂
Actually I think I can answer part of this. I’m not any expert but it has to do with the shape of the contact patch. The narrower tire let’s say 23mm at high pressure vs a 28 at lower psi has different contact patch. The 23 is long in a 12 to 6 pattern whereas the 28 has a stubby 3-6 patch. That’s how it was explained to me. But not sure what tire contact patch is bw 28 vs 35.
Still think there's more variables... My vintage ('84 Bianchi Sport) bike came with 700x25C tires, and in the late 90's I changed over to 700x23C tires. I can attest that these are a tad slower top speed wise... Except I can also attest they are faster when it comes to cornering. On 25C tires this bike does not like to turn - no matter how hard I tried, the bike would only turn very wide at lower speeds (even when having it leaned over far enough to scrape a peddle at the top of the stroke on the ground). On the 23C tires, I can carry more speed into and through out a corner with out the corner the bike wanting to make huge wide arcs. So perhaps geometry has a play in this debate as well? Anyways, I'm not going to advocate any tire size - find the tires that work best for you, your bike, your needs, and where you ride and use it. If the size ends up being 23C or 35C does it *REALLY* and *TRULY* matter? 🙂
I recently purchased a Pinarello F5 105 Di2 and it came with 28mm front tire and a 32mm rear tire (supposedly what Pinarello suggested to the company I bought the bike from). But I set it up tubeless with 28mm front and 30mm rear. Seems to work just fine, and I don't feel like it's any faster or slower than normal. Overall it's a heavier setup than my older Felt F4 with 25mm tires (with tubes), but it's a comfortable and nice ride.
I've used 25 and 28mm on my road bikes. With each jump in width you get a small weight penalty(20 to 30g's) so generally I go with the 25mm, and also these best suit my rel. narrow rims. And I like climbing. About a 70g/tyre difference from 25 to 32mm
I feel the same way I've gone between a 25-28 tire over the years. I'm on a rim brake bike so 28 is my max. I don't notice any difference in feeling between a 26 or 28 but I know it is lighter
Try to calculate the the time penalty of the extra weight up one of the climbs you do and you will find it's close to nothing with 140 g extra system weight. On the other hand improved rolling resistance will probably more than even out this weight disadvantage
Yeah all that is true. Most of it is just psychological and feeling good with one's equipment. Pro's throwing empty gel packets out of their back pockets before a climb isn't going to change anything either, but they still do it ;) I know with my own race results as an average amateur, that in the same races over years, on widely different equipment, that the only thing that really matters (assuming good tactics) , is ones form and fitness, and how many watts you can push on the day. This determines time and placing much more than anything else. Everything else is just window dressing basically unless you turn up on a Brompton or a BMX. Hence the endless equipment debates splitting hairs lol
I did discover one issue with wider tyres, at least in the winter on muddy roads - it became really hard work when I ended up with a thick layer of goo wedged between the tyre and the mudguard due to insufficient clearance!
Funny the call out to crosswinds with fat tyres and less far rims. This my my findings too when I ran a 35 on a 32 external rim. Went back to a 30 and the crosswind instability was greatly improved
same, I rode 32mm Schwalbe Pro Ones on my carbon rims (32mm external) and the crosswinds almost made me crash when i was hitting about 70kph, going down a big hill. Changed to 28mm and the stability improved drastically.
32s were also worse than 30s and 28s crosswind. But with 28s I cornered on the sidewall which kept damaging the tyre, so 30s were the sweet spot@@DB-sj8km
I was a traditionalist of 23mm for years, going on physics of less contact point equals less rolling resistance. I have yet to jump up big. I now run 25mm but may try 28mm next to just see and compare routine routes in Strava and Garmin to see any benefit on my Cannondale SSE with carbon Spinergy wheelset.
This seems like the best argument for wider tires. I think you touched on an interesting point that until recently, wider tires were only available in lower performing configurations. I would venture that on a rougher more common surface that the wider tire would provide a notifiable advantage. A higher speed test would be interesting, to compare Aerodynamic advantages or disadvantages.
makes nearly no difference, altho theyre a bit heavier. they are faster especially when the roads get worse. also a larger surface gives more grip on like wet or slippery sections when making big power. also descending will become better on the wider tires.
I've been running 32 Conti 5Ks front and back on my Cervelo S5. It's way more comfortable than the stock 28s. Cervelo says 28 is the best aero match for the Reserve wheels in front, but I haven't noticed a difference in speed, just comfort. I've just gone down to a 30 in front to save a little weight, but it feels about the same as the 32 so I may go back up. I'd certainly rather be on 32s in the rain.
I used in the past 5 years 32mm tires (schwalbe one, gp5000, gp5000tr, pirelli next), i really liked it, because i used sometimes for light gravel. Last time i bought 28mm michelin power cup, and i enjoyed it the most on asphalt. I guess this is the most important, which is the most enjoyable for you. Anyway, the rolling resistance tests with compansated pressure show the same… very similar watts.
There one more thing to count. with the 35mm tire when you do a full rotation of the wheel you go further than the 30mm and the 26mm tire. So for the same RPM you go further.
I'm currently running 42mm slick Cannondale/Panaracer tyres on my Slate for commuting. I feel they are as quick, if not a smidge quicker, as my 30mm Hutchinson Fusion5 on my Synapse. And comfort is amazing!
Physics says the main difference will be in acceleration due to inertia of a bigger tire. But even 35mm is still a thin tire if we view it objectively.
I did some rides last year on my gravel bike with 35mm smooth (almost) Panaracer tires and then some with 32mm Contis. They measured 37mm and 34mm respectively on 25mm IW rim. The comfort was amazing. This year I went back to my road bike with 28mm tires and they just feel too harsh. So I’ve upgraded the wheels to DT ERC with 22mm IW and just mounted 30mm Contis on them (31mm wam). Comfort is much better, descending and handling are more confident too. The way I see it - there’s no reason whatsoever to ride anything less than 30mm. All the people that say their 23/25mm tires are faster - they are not. They just feel faster because at high pressures they are less spongy. So you feel your bike trying to jump in front of you with each pedal stroke. But it’s just a feeling which, apparently, does not translate to actual speed gains.
32 has been my go to. 28 feels faster, but that is almost certainly just a feeling because of more feedback and the perception of a twitchier bike. Very cool. I much prefer the comfort of wider.
My prediction is that road bikes will settle to use 30-40mm tires and anything above 40mm will be called gravel. Also the internal rim width will settle between 25-35mm depending on the width of tire used. This season I am putting 30mm internal width aero rims with 34mm tires on my bike and enjoying the comfortable and fast ride.
I just got a pair of 30mm pirelli race tires with a new used bike I bought, haven’t tried them out yet cause I’m still hitting the gravel hardest right now, but I am excited to give them a go later this year, big jump from the 23mm I was riding
Hi Darren, I've got a 1998/1999 Cannondale R800 alloy frame/carbon steered. I can just run 28 conti 4000's in this frame, clearance on rear dura ace rim brake a few millimetres and on seat post. Maybe a mates got some 28's you could try? It made a comfort on my old girl much better. But it's what you like and prefer ultimately!. I still think I'm faster on 23's/25's than science proves otherwise l!😂
On my last bike, I ran 25c tires, but the wheels (vintage Giant TCR wheels) used carbon spokes. they were SUPER supple. I now have 30c Conti GP5 TR tires on my SL4 Roubiax with the stock Roval CL40's. They run a maximum of 75psi, and they feel TREMENDOUS.
Over a route I ride regularly which is 29.4 miles I am consistently quicker all the time on 23ml tyres versus 28ml tyres for reference roads are average and my weight is middle age spread 😅
By how much? On exactly the same bike and wheels? Is your power output the same for each ride? same wether conditions, clothing, and rider position, & total weight? There are a lot of variables, but nearly all tests such as those by GCN show either negligible speed / power difference or a small improvement with wider tires at lower pressures. Your results would be an outlier, so maybe your test methodology is flawed?
I only have the one bike so all I do is change the tyres it’s normally about 5-10 minutes the time I notice it most is when I swap my tyres to wider ones for the winter same make brand just wider
What bothers me is that advocates of narrower tires are being characterized as climate change deniers. Everyone trusts the science, yet the data that exists is inconclusive. Like the drunk looking under the street lamp for his car keys, when asked why he was looking there, he replies “Because where the light is!” … “Garbage in, garbage out.”
One thing I notice is that they're on a circuit, which is very different to real world use. I suspect where you'll notice a bigger difference is in things like acceleration from a stop, which is important when out in traffic, where the weight of the tyre becomes more of a factor.
Si, once again my friend, you didn't let me down. You did the tests, and the results showed that the 35mm were marginally the fastest, and you already know that they'd be the most comfortable, and yet what did you have to say? "I still wouldn't put those on my Pinerello!" Good for you! Never let science stand in the way of you thinking you look cool. Meanwhile, for the rest of us, put the wider tires on your bike and enjoy the benefits of less rolling resistance and a more comfortable ride.
28mm on road bike and 38mm on cross/hybrid....still getting used to lower pressures grew up in the eighties using 120+psi at 23mm on the road...interesting and much more comfortable riding, after watching your previous video's started exploring pressures ...and yes not much difference in average speed although hybrid is a heavier, bigger frame than the road bike so a bit slower anyway..... am also really enjoying using better compression clothing as my bones get older so much useful and comfortable new kit ...thanks for your insights have a great week
Which casing do you use? And what do you think of them? - Extralight (most supple but kinda puncture prone) - Standard (slightly stiffer and not so supple casing, more affordable) - Endurance (same thread for casing like extralight but more dense and therefor slightly stiffer, more puncture resistant) I'm also looking for the 35C one (Bon John Pass) and wonder which casing to choose. At least I don't want waste my fun and time to punctures, but wouldn't slow down with a tank tire. A friend of mine got the Extralight and put some effort into it with sealant just to seat the tire on the rim and for sidewalls bleeding. Probably 80 ml just for that, plus 60 ml for possible punctures. This would lean me more towards the Endurance casing (overall effort, weight, safety to keep riding) while seeing no benefit at all (beside money) for the Standard version.
I’m very excited because I just ordered a new bike with clearance for 45mm tires. I’m planning to run 40mm with fenders in the winter, the switch to my deep section rims with 30mm tires for dry days and fast group rides. I’m hoping I get similar results and then I can ditch the “road” rims and just run big pillowy tires all the time!
🤔 What width tyres do you use? Have you gone wider and noticed any difference?
Let us know 👇
I like 28s comfort compared to the 25s.
I wonder if you could run the same tests on the road. Some other channel suggests that 32s are the fastest.
Seems like for most of us, the subjective feeling matters more than numbers. Personally I love the snazzy acceleration feeling of the mid (28 but measured 30mm on my rims) when going uphill. Love these comparisons! Thanks a lot!
I run 100mm because roads and paths are so bad. But it needs electric assistance
I have just moved from 30mm to 34mm Vittoria Corsa Pro - I completed the Peaks Challenge here in Aus last weekend and given the condition of the roads - I am sure they assisted me!
40-50mm
racing 32mm conti gp5ks this year on the horrible belgian roads. they feel so good riding the rougher sections and flying over holes in the road
That's what I ride on the crappy UK roads. I'm using 50mm deep gravel rims that sit almost flush with the side of the tire. It's about as bomb-proof as you can get for a road orientated wheel without going gravel tire
You are riding Edh for sure 🙈😂
How about uphill? Is 32mm not slowing you down?
32 is the new 28 🙌We bet those wide tyres grip the cobbles 👀
@@gild5942it’s hard to feel the difference the extra 60g of weight makes. To test the effect on your own bike, add 60ml to a drink bottle and ride uphilll. Then remove the 60ml and ride up the same hill. See if you feel faster. The power difference to travel at the same speed is less than 0.1W
At the end of 2022, I retired my racing bike (23mm tires) and bought a new endurance bike (30mm tires). I thought Id have to change them out for 26mm to stay competitive with my buds who all have racing bikes with 25-26mm tires. But after riding for a year+, I am riding faster than I ever have. Please do me a favor and stop making these tire videos before my buds catch on to my secret!!
P.S. Love the tumbleweed segment.
how is 30mm faster than 23mm ?
@@Religion-Geschichte-eh7hm Did you not watch the video?
Watch the video.. but rolling resistance at the optimal pressure is lower for the wider tire. That is why the chart shows the largest variation at slower speeds where rolling resistance matters more than the air resistance as a percentage of total drag. Once you are going faster as seen in the 300 watt chart the tires are the same because tire differences are a smaller than air resistance at high speeds. Air drag increases at the Square of speed.. @@Religion-Geschichte-eh7hm
Same here.
I changed from 25s to a 32 and my times & watts were relatively the same.
What did change was my endurance on long rides. The 32s gave me an additional 30km spot on.
LOL, you don't understand what "training" is :)
I sure hope you guys (GCN) can keep going with the loss of the network going away . That really sucked. We all loved your channel GCN+ here in the states. Such a great amount of well thought out content and great people!!!
thanks for the support 🫶
I was wondering how this was going to work after that news. You have my support!
I loved the Himalayan special! Bring back gcn+
What happened?
@@PaulAlexanderrr www.youtube.com/@gcntech
they have this channel but I'm not across the swap gossip i'm in Aus
Im using the 35mm Continental GP5000 All season tyres. They arent cheap but worth every penny. So much comfort and almost no speedloss. Loving these tyres especially in the rainy seasons.
No speed loss is quite a stretch.
@@tonyg3091 true true.. but it really is marginal. If you're not riding in races it really doesnt matter that much.
I just bought Pinarello Dogma X with exactly the same tires as yours. I can't wait to test them once the winter is over (I hate the cold in Poland) ;)
@ttospp kuuurwa!! sounds amazing! Enjoy 😍.. i live in the netherlands, i only ride my bike to work atm, weather is awfull indeed haha but i bet its freezing out there in poland now haha
My new bike came with 25s on modern carbon wheels, and when I upgraded to 32s, it was like I had a whole new bike - loads of PRs on the first ride, felt so much smoother, and the control around potholes etc. was just better. Thank you for showing us the science in videos like this that helped me take the leap!
This is what we love to hear! Fat tyres really are a game changer aren't they 🙌
Many years ago 19mm was your race tires…21mm was your training tire and a 23mm was like….”why don’t you just get a mountain bike?”
😁
So true… and I’d bet with newer science when industry decides so, narrow will be in again for some innovation reason.
Good times. Too bad I missed them. Btw. Were those 19mm tubular or clinchers?
Pot holes weren't really a thing back then!
😂yes... They invented potholes recently@@richardmiddleton7770
2:04 is the definitely the real star of the video!
Alex lost his Mike sock.
I genuinely thought it was a fearless curious little country mouse. But alas...
Tumble weed for the win 🙌
@@gcnlol
Tumble zaza
Several comments in one (for no extra cost):
1. Great video, great discussion, nice little tumbleweed..
2. It's taken a while for the bike manufacturers to offer road bikes - race & endurance - with enough tyre clearance to allow up to 35mm
3. If those tyres are all effectively the same performance, on the same rims, then the 35mm will offer even more with wider rims (say 31mm internal)
4. The 35mm tyres will be as much as 100 grams (2 x 50) heavier than the 26mm tyres.
5. the 35mm tyres, especially for tubeless, will be easier to mount & unmount on/from the rims
6. no-one ever discusses the possibility of using different widths front & rear, despite known wind profiles for such (as in TT bikes). I use Vittoria Corsa 28mm (measure 30mm @ 75psi) on front & VC 30mm (measure 32mm @ 75psi) rear on my Cannondale Synapse. I'm 81kg. Terrific balance, performance & wear. Upgrading to 2x 35mm....
Nicely done! Really like that you kept it to a single variable as much as possible, and had a variable-checking final run. That graph really tells the story. Kudos! Thanks for running the exact test I’ve been looking for!
Glad we could help 🙌 Thanks for watching, any other test you think we should do?
2:03 Best scene of 2024 so far
Absolutely love this content! Love the gcn does science videos! Well done you two. The results surprised me because of the surface. I started going for more width after reading Rene Herse's myth busting articles. While riding the Northumberland Hills (Ontario) I was amazed that my 40mm Schwalbes (which are tanks with stiff sidewalls) made my normal gravel routes much faster. Fast forward to today, I run 44mm Snoqualme Pass Rene Herse on my touriing bike, 40cm Schwalbe Marathon Supremes on my stepthrough citybike, and 35's on my exercise bike. The most comfortable and fastest are the 44's. Like you, when I moved up in width I noticed the difference in handling, but I like how the Touring Bike trails. Thank you so much for this surprising and interesting content! Well done! More please.
thanks for the love! We love to do science!
Sponsored video, no science here
I went from 25s to 32s in 2007, when I got a frame that would fit them. It was non disc frame, so had to let air out to put it past the caliper brake, but ran a disc fork, so no worries up front. A few years later, got a new frameset & went to 35s. I wanted even larger, but had to put adjustable dropout all the way back to get 40s in there, which made the bike handling more like a touring bike, so last year had a titanium frame made that could fit my desired road tire, the Rene Herse 44 Snoqualmie Passes (measures 42.5mm on my rims). Best decision I ever made. Might seem like overkill, but the country roads I love to ride on, they're perfect. I even went this winter without putting on my winter wheelset with 42mm knobbies, which will now be relegated to offroad use only.
Doing a new bike build this year and will make sure the frame can take 35’s. Currently limited to 25mm on my 2015 frame. Most of my riding is rough roads so can’t wait for the change.
Just get one of the new Aero Gravel frame sets. No need for a road bike anymore unless you're racing.
I’m doing the same thing except for 45mm. Very excited to ride on pillows!
I have one bike, cyclocross, that I do everything on. I run tubeless 38s. Fast and comfy, love it.
Cyclocross geometry is the true do it all bike geometry.
Fast is relative.
Nothing wrong with the cross bike 🙌
I also have a cx bike as do-it-all, as in N+1=1. There seems to be some variability in the geometry of cx frames though. I've seen quite aggresive geometries out there, but for example mine is actually more like an endurance road bike, even though it's the brand's cx entry level frame. They even tag it as endurance in their website lol. I can run up to 40mm on it, but am also limited by mudguard clearance in the winter.
I had a giant tcx that had kinda cross specific geometry with the higher bottom bracket. With road slicks it was exactly the same speed on the road as a road bike.
I run a set of @Reneherse 48mm tires and have zero problems keeping pace with the group I ride with. Bonus, I'm less fatigued at the end of our 100km rides.
Less fatigue and just as fast, what more could you want 🙌
Sounds pretty good!
Which surfaces and speeds you're talking about?
Me myself thinking of an 35C at a 30 ID (38WAM).
Happy to hear I’m not alone! My Topstone has RH 48 on front, 44 in back (as wide as will fit) and in informal rolling tests they roll no slower than the next guy on his 28s.
Some caveats though: at that width (and corresponding low pressure) they do get “bouncy” when pedaling hard, both sprinting and climbing. And a bigger tire is heavier for sure, so perhaps not the fastest to get going. Finally the pneumatic trail change is real; I will likely go back to 44 in front on my next tire change to make the steering a bit snappier. (On the other hand, 48s on 650Bs on the same bike are downright playful)
@@gunterhackstock4480 , roughish asphalt, speeds +/-30km/h.
How much heavier are those 48 tires compared to a 28mm? It seems that would be the main difference aside from windy days..
I'm still getting over the micro tumbleweed and Si's reaction to it! 😂
Rumour has it, that tumble weed has followed them around 🤣
Pretty sure that was cut grass.
Good vid chaps. Makes me wonder where the limit is. The best selling tyre in our shop is easily the 30mm now.
Currently riding Vittoria N.EXT 28s at 60 PSI. Thinking about switching back to ENVE SES 29s and dropping 5 PSI. I like the tyres for the level of puncture resistance. Love your coverage as well, Paul.
@@jamesmckenzie3532 🙏
I'm thinking the same. The way I was struggling to keep up with a mate riding road tires on my 650b - 1.9" gravel tires, I'm definitely thinking there is a turning point, but seeing 35mm do this well, it's probably at a wider width than I'm guessing.
That's super interesting! Why do you think that is? Are people riding fat tyres on road bikes or slimming down gravel bikes?
It depends on the surface in all reality and the context of the effort. Thus it is always a "it depends". For TT specialists it is a much more thorny question because they are actually working both parts of the "CdA" variable directly...a few Watts can be the difference between a win and 2nd. With modern rims the Cd part of CdA is better management but the A still exists...it always exists. Thus it comes down to "what solution best matches the course and tactics requires".
Great video. Jan Heine figured out-and proved-this apparent paradox a decade ago. Si, you said you’re reluctant to go with 35s on your Pinarello, but try a pair of Rene Herse 35s and you’ll never ride anything else.
Oh yessss, Bon Jon Pass Extralights for the win! 🤘🏼😎
It's not really a paradox; the science has always said wider tires have a rolling resistance advantage. The paradox is really why the bike/tire manufacturers have denied it for so long.
@@xungnham1388 why does the science say that? Please explain
@@nowthenad3286 The area of the contact patch the tire makes with the ground is a function of (weight over tire) / (PSI of tire) = (square inches of contact patch). For example, 100 pounds over one wheel / 90 psi = 1.11 sq-inches. This relationship is largely glossed over in most people's high school physics class which is why most people aren't familiar with it, but if you ever see a method to imprecisely measure the weight of a vehicle by measuring tire contacts and tire psi or hear advice about letting air out when stuck in snow/sand or why semi trucks need 100+ psi whereas cars are designed for 30 psi, this relationship is why.
In our bike example, that 1.11 sq-inches takes the form of an ellipse with the width of that ellipse dictated by the width of the tire. Comparing the patch between 2 tires, a wider tire has a wider contact patch over a narrower tire. That also means a wider tire has a shorter contact patch than the narrower tire, given the same contact area. A tire makes a contact patch longer by deforming it's shape, it squishes in. A longer contact patch of a narrower tire means the tire has to deform more than a shorter contact patch. Tire deformation is where the majority of rolling resistance comes from; having to constantly re-squish new spots of the tire as it rolls along a flat surface is what robs a tire of it's motion energy.
My cyclocross super commuter came with 32 mm cyclocross tires, which are soft, do not last long on the road and I kept getting flats. By me being a road cyclist, I decided to switched over to 35 mm heavy duty anti-puncture protection road tires, installed tire liners inside the tires and slime sealant in each inner tube for additional puncture protection. I must say due to the additional weight of everything, I am not able to travel as fast as previously, but the ride is more comfortable and I am no longer concerned about getting flats. I have absolutely no regrets in doing so.
Great point by Simon @ 10:00 that before wider tyres mostly seemed to be tank tyres, super heavy puncture resistant types and now so many great options in wider sizes.
Except for Rene Herse (formerly Compass) Jan Heine was onto this wide road tire thing YEARS before the rest of the industry, and he's been making great, supple, wide road tires for a long time.
Never going back below 32mm, and I am here for trying out 35-38mm. I am a casual biker on a road bike, worn pavement with some cracks, 5% gravel, 5-10% smooth surface.
Why do suffer with
Try 35mm. It's just as fast but much more comfy to ride over bumps, cracks, cobble etc. I pump smth like 4.2 bar in them and it's been great so far.
Total game changer
Road bike is for good surface. Gravel, dirt road, cracked pavements? Buy a nice MTB as a second bike. Really wide tires, 1,3 bar in front, 1,5 rear and you may go over deep sand as well
@@exucontongood advice but speaking for myself, I’ve never liked flat bars unless I’m handling some really gnarly terrain. The gravel bike revolution has served me well! I can ride just as fast on smooth roads as before (notwithstanding my advancing age), but I can also ride in scree and gravel with no issues or discomfort. Once I start having to deal with roots and big rocks, I know I’ve lost my way.
Thanks so much guys, I’ve been debating getting a set of 35 mm slicks for my gravel bike for road use and you’ve sealed the deal 😁
I have 34mm corsa next on my gravel. They are nice. Speed limitation is on grx gearing, not tire
What about climbing? Wider still better?
Check back in and let us know how you get on 🙌
Well... i cant really tell when climbing. It is slow. Im on a gravel bike a bit heavier than the old road bike, but gearing is lower... so up is easy. Not sure it is faster or slower. Going so slow it is not bumpy anyway.
But down really bumpy roads is waaaaaay faster with slack gravel geo and chubby rubber.
I will also say that i did a 135km ride with 2800m climbing with about 10km on a gravel road with these tires. Better than the guy i was with who walked hos 26mm tires the entire way.
We kept pace everywhere e cept the steepest parts with me on gravel bike and him on wiggle carbon road bike with skinny tires.
He did outpace me on a couple steep hills... but i think only because hos lowest option was 34:30, and mine was 30:36, so i could go up slower... he HAD to go up faster, or walk
I have 38mm slicks on my gravel bike for commuting (SCHWALBE PRO ONE TUBELESS ROAD TYRES). They were the widest I could find. So comfortable and no noticeable loss of speed over the 25mms on my road bike.
I'm still on my 23s. This year, finally, I will finally try something bigger.
Just made the change from 23mm conti's to 28 goodyear eagles it does help.
Honestly, as my bike is a 30+ year old steel relic, I reckon tyres are probably 90% of the difference with modern machinery that and about 3kg in the frame 😂 ... but that just trains the motor harder! 😉
Uhum... You need something bigger, yeah, bigger... Uhum.
@@laster509 I'm assuming you are referencing Beavis and Butthead or I'm stuggling to get it...🫤 Right, I'm off to the shops to buy TP for my bunghole.
That's what she said
I dont even think my old 1989 roadbike can accomodate anything wider than 25s 😂
I bought a new bike last year so that I could accommodate 35mm tyres and I'm glad manufacturers are producing lighter tyres in those widths now. I didn't even know you could get a Pirelli Pzero that wide until this video. I can't believe I once ran Michelin 19 in another life. I love riding bigger tyres at lower pressures
It's pretty incredible to think we used to use 19mm tyres!
10month on 35mm now.. never going back.. tarmac, dirtroads, potholes.. it eats it all.. 🚴♂️👍🏻
im using 38
What was the velocity vs watts for a given tire size? Time to distance is meaningless since there's huge variability in the line taken / distance traveled around the track. Also, a torque transducer at the front wheel is the only valid way to determine rolling resistance.
Crazy I was literally looking for this info as I'm looking for new tires thanks
This spring I will go with at least 30 mm. Thank you for the video - I love such tests! :D
I went from 28 to 32 and I'll never go back. My next bike will have 35. Put the widest tyres your bike will fit.
Amazed how consistent your results were for all the variables you would have in that kind of test ...spent 30 years in the tire industry,... to measure what you were trying to demonstrate we would have done in a controlled indoor environment on a test drum with various grits to determine friction coefficient. As a recreational and Club cyclists for many years I have transition from 26 to 30 on the road bike with no loss of speed but more comfort!
Great to hear you enjoyed the test! 🙌 How has the 30mm tyre improved your comfort?
It would be interesting to consider many aspects that relate to a complete ride and how to test for those aspects, the:
- amount of difference friction / aero related energy, compared to the distance travelled in order to show the differential
- variation of contact patch dimensions for the same rider weight, for different width rims
- some sort of roll down test
- typical and potential maximum gain related to surface roughness, versus mass when climbing
- sprinting / cornering loss for width
Perhaps there is a Goldilocks point related to cyclist weight, tyre pressure, and tyre size.
Bigger isn't better, smaller isn't better (especially in all circumstances) - so maybe a zone of generalization depending on usage.
For sure whilst as a teen I used to enjoy my 19's on perfectly smooth cycle tracks, apart from them shaking your eyeballs - pot hole flats, and wet manhole covers could be treacherous.
Understanding ride speed and when each variable becomes a key factor would be all consuming.
@@barrylewis8916 I'm definitely with you and you totally nailed the factors to be considered!
In general you couldn't say either one size direction is better, but for most riders even not hitting the sweet(est) spot some could really argue to better step one size up than one down.
Might be that 32C for (mostly smooth) road use is the limit in size up...
Might be that 35C for (smooth to rough) road use is the limit in size up...
Might be that 45C for (mostly smooth) gravel use is the limit in size up...
Might be that 50C for (smooth to rough) gravel use is the limit in size up...
It would be much appreciated if someone can do the circumstance dependend analysis. From this a data set could be created and then very most riders could easily look for their ideal tires when entering their data (weight, surface, climbing ambitions versus distance ratio).
Zero Friction Cycling for example, did this with lubricants and from now on it's as easy to select the one of choice regarding the cicumstances of riding and needs (enviroment, costs, friction).
KUDOs for any effort to this kind of direction!
Great vid lads! Running 32mm on my Trek Domane and I feel pretty happy with that size. 35s would seem more like gravel bike tyre size to me.
Would you ever make that jump to 35? Could be perfect for a classics style bumpy ride! 🪨
Wow, so many comments, I'll be surprised if you can read them all! I live in the mountains (Asheville, NC) and our "typical" ride has 1000 ft of climbing per 10 miles. Weight is an issue for us. There will always be a compromise on weight with bigger tires. Also, I still run tubes (!!!), so going w/lower pressure (to a certain point) is always going to be a risk of pinch flats. So much to consider...
Don't get your argument with getting more pinch flats when lowering the pressure on an existing tire or a different/wider tire. If you go too low, you give up speed and risk damage to your rims (and tubes). On MTBs you can get an snake bike flat.
For sure, wider tires are heavier. In contrast you get a comfortabler ride and let you put more power to bring on the ground therefor.
Don't break your head, just because the weenies discuss the general sweet spot shifting. ;-)
If you're unsure, take a tire size up, as most users are getting more comfortable with.
Watching for second time. Excellent video. 35mm - 1(3/8)" in old money, now, when do I remember that from? It took me ten years to move from 27*1(1/4)" Weinmann concave rims with Weinmann 500 brakes to dual pivot Shimano 105 (the greatest game changer in cycling history of the last 40+ years) to 1(1/8)" to 700C Mavic MA40 with 25mm then 23mm tyres. Said before, best ride ever was 120 miles in rough lanes of North Downs Kent on 2007 Cannondale System6 Ultegra, Mavic Ksyrium Elite wheels with 23C Vittoria Diamante Pro tyres at 160 psi that lasted just 300 miles, as reviews said. More affordable tyres, nowhere near as nice a ride.
Age 69, I get the return to fatter tyres. 10 mins in: the quality of the fat tyres is what is the big thing. Back in the day, bomb proof commuting or cycling for work meetings all over London: Nutrak Nomads, then Schwalbe or similar fatter tyres with horribly hard treads were slower and less comfortable than narrow quality tyres. Big mistake was buying used Roubaix Elite in 2018 with 25C tyres. If I could, I'd order wider rim tyres to take 32mm+ tyres today. But I can't afford £600 to £1k for wheels, tyres, tubes. Ideally, I'd change the bike to aluminium and clearance for quality wheels and 35mm tyres.
Also, amused by attitude to rim brakes. Shimano 105 on aluminium rims in 1980s gave all the stopping power and control in any conditions that anyone ever needs. But... it also wore down the rims, which could be expensive so, despite the more complex maintenance of disc brakes, I think I prefer disk brakes, especially when the rims get wider. V-brakes on wide tyre road bike (eg first generation Tricross after the recall of the dreadful caliper brakes) never had the precision of Shimano 105
I still ride 23mm tubulars. Would love to see how they compare on that surface, not that I will be changing. For the riding I do now (leisure) cannot see the point in buying new wheels even if it means going tubeless. I am old and I like tubs!
Still race on tubs myself I still feel they corner better and I like the fact if I flat there is still rubber on the ground not just the rim.
You could move up to 25mm tubs, if you can. The reality is the difference between 23 and 25 is a bigger jump than 25 to 28.
Just because you're old doesn't mean you have to be stubborn and stupid.
There are 25/28/30/33mm tubs (road and CX slicks)…no need to change the wheels for them.
22mm tubular I use as match rim width, love as stay on with flat front at 42mph downhill
I hate going should I upgrade hub and spokes so maybe 870 or less or save to build Trek Emonda ALR to 7.3kg (computer, lights, bell on bike, with pedals)
I’m a fat tire guy. 30 - 32’s for my road bike, 38 - 42’s (42 is the biggest that’ll reasonably fit). Last time i rode 25’s was in a race. Roads were not great and as soon as I got home, I took them off and threw them away to remove the temptation of ever riding 25’s agin.
Just bought gp5k 30s. Haven’t ridden them yet. I’ve been riding 28s for several seasons. Maybe I should have gone all the way to 32s great video. Very interesting
Hi, thanks for the comment and glad you found the video good 👍👍
Nice to see DRIVE wheels on GCN. The 50D and 65D were my favorite wheelsets for ~2 years until other brands started to coming out with wider external AND internal wheelsets for a similar price. Hard to beat the 50D for price to weight ratio.
I ride 35's with my steel commuter. The roads are shocking, and this video convinced me to keep them on for the Summer 👍
I will get my gravel commuter as soon as it‘s available again in my size and will buy an extra pair of light wheels with 30-35 on.
Road surfaces are so abysmal in the UK I would always ride thicker tyres 26mm plus
Heck yeah, I’ve got 38s on mine and even in Tokyo there’s some rougher bitumen on some of the routes I take & comfort is so different between my 28s & 38s
I'll be upgrading my 32's to 35's after watching this video. My bike takes 38 but that's without mudguards.
Got my first road bike in 2018 and also started watching you to learn something. Right away got the feeling that wider tires are the way to go and always used the widest tire my frame and rim brakes could manage. Two years ago I got disc brake bike and am running 35c since and I'm never looking back.
Recently switched to 30s from 28s (both GP5000, on 21mm internal rim width wheels). Definitely feels smoother, and no perceptible downsides. Moving fron 25s to 28s (still GP50000) was an even bigger jump. You brace yourself for a patch of dodgy tarmac and just sort of glide over it - that's the best bit.
If it fits (that's what she said), put 32C at the rear. Material difference between 30 and 32 in comfort yet again. And at the rear you have zero aero penalty. Also means you don't worry about sketchy surfaces anymore.
OK, that does sound pretty good.
Put the widest tires your bike will accommodate is the rule of thumb. You're already paying the aero penalty (if there is one) with the width of the fork and rear triangle so you might as well be as comfortable as possible.
21c rims means it's already a gravel/monstercross bike? I have them on my specialized AWOL, mostly do tarmac and i've fitted some slick 55mm tyres which are great, but just because of not having to worry about frame clearance, i'll eventually switch back to 35mm. They're best compromise imho, always depending on one's riding needs of course. No need to push tyre size to the frame's limit and them risk rubbing, be it one far day in the future, but still...
You were probably running the 25's too hard.
Running 32mm GP5000 S-TR tires at 3.5 bar on Zipp 303 Firecrest wheels on my road optimized gravel bike. Smooth and grippy. Being a gravel bike, I could go to 45mm but that's reserved for off road activities.
I do run the widest tires I can on my road bikes but I'm limited by frame clearance. 25mm on my 2011 Trek Madone and 28mm on my 2019 Trek Madone SLR. Both are rim brake.
I just swiched from a 28mm to a 30mm in the rear on my road bike and even though my condition and FTP is at a low point i already did some PR's which surprised me a lot...
I went from 26 to 30 on my Pinarello Prince FX and that was the best decision I made starting the new year. So much better on every department
Would you ever go bigger than 30? 👀
32mm convert here, front and rear. I love them. No turning back (to narrower, anyway). I think I’ll try the 35s though next go-around.
It's almost like I wrote this. I want to get a Trek Domane because it fits 35.
Lots of love for 32mm 👌Comfort and speed, what more could you want?
Just found this channel and have not stop watching it for the total weekend. Great stuff thanks ,keep up the great work.
You guys did what you could to keep everything equal except rim width.
The "rule of 105" (rim width should be at least 105% of tire width) means there will be aero losses running a wider tire on the same rims.
The test also doesn't measure rider fatigue which will increase with narrower tires at a higher pressure over longer rides so even if a few watts are lost to aero the effects of vibration from narrower tires will probably sap some watts from the rider.
They kept the wattage constant so rider fatigue doesn't factor into the equation.
And if the rule of 105 applied then surely the wider tyre would have been slower - what you're essentially saying is that the wider tyre should have been even faster than it was!
@@RH-nk7eo I also think that applying the 105 rule, the wider tire with adapted wider rims would be slightly even more faster. Especially because the wider rims can be of equal weight or added weight will be outperformed of aero benefit.
If the (wider) rim would fit the (wider) tires more properly, it seams to gain more of the aerodynamic effect than the loss due to being more heavy.
I'm also with the argument of Surestick88, that the additional fatigue of narrower tires that will be added to the (for sure constant 100 W) power transfered, will slower the narrower tires in the long rong.
In my opinion the 35C tire would be best compromise of weight (for climbing and acceleration), frontal area (for aerodynamic), comfort (for fatigue resistance) and rolling resistance (for smooth tarmac to rough roads/bike paths)!
Some may find their sweet spot at 32Cs or 28Cs front and 32C back; and might step up in the more future. ;-)
That said, looking forward to get my hands on the (currently not available) Pirelli P Zero Race TLR 35-622 to be mounted on the Light Bicycle WG44 rims (30 mm inner dimension, 38/40 outer dimension).🤩
I've used my Trek Domane with 35c Schwalbe G-One All round on paved and gravel roads and have managed close to 30km/h at one point. I was only slowed down by street signs and Red lights
Not a show of strength but rather something that supports GCN in this video
Great to hear that mixing things up has helped you improve 🙌 Pesky red lights always slowing us cyclists down 🤣
I used to have 19mm tyres back in the 90s. Moving up to 23mm was pure decadence!
Haha me too, now I have 28mm. But I'm 25kg heavier
I'm on 23s myself and if 19s were still available, I'd be on them at 140psi.
@@johnandrews3568 you can still buy 19s if you really want them🥴 No idea why anyone would want them. I won't even run anything under 25 on a velodrome anymore
@@veganpotterthevegan Link?
@johnandrews3568 can't share links on RUclips anymore. But look at 700cx19 wheelchair racing tires. They're interchangeable and most wheelchair racers just use conti 5000s anyway. No idea why you'd want slow tires though😂
I raced against local sprinting Strava segments on a “fitness bike” with 36” Schwalbe tires and I broke many records.
As I started loving to ride the bike I then bought myself a proper racing bike. Now I m riding on 25 because I like the road feel.
I've been running 32mm at 70psi for a couple of years now. In truth, it was only last year that I dropped the pressure. I mainly ride on Suffolk country roads, and on these tyres, the ride is so much more comfortable than my previous 28mm (21mm before that!). Great work guys 🙂
Been running 28s but they come up at 32s on my rims. Through the back roads of tunstall and rendelsham they are spot on
I have been using 30's and recently moved to 32's. More than just the speed, if one is riding for few hours, the overall comfort you get from a larger tire over the longer period is just nice.
Fatbike riders have left the chat
Nice one
haha, I know I haven't. 4" all day
😅🌐😂
Nah; I'm still here. You just can't spot me cos I'm riding through a swamp right now ^_^
My Scott Solace 20 eRide came with 700 X 38c. A size I had never ridden before on a road bike. Most of my past bikes have had 32 or less. For me, I could feel a huge difference. The Solace 20 is such a smooth ride. Now, I'm not racing it but when I pick up the pace in group rides, it performs perfectly. But the huge advantage is on uneven roads. That 38 at 60 PSI smooths out the bumps.
Well BicycleRollingResistance did this test like 5 years ago, and this is exactly what they found out. At the same pressure, the wider tyre is faster. But at the same comfort level (or as they measured it - the deformation/tyre drop under the same weight) the results were pretty much identical in rolling resistance.
Yes and therefore his conclusion in this particular article was: take the narrowest tyres possible that meet your comfort requirements (not bottoming out and not risking pinch flat). Wider than necessary is just adding dead weight.
I love the sample sizes on all GCN experiments. 😎
I read an interesting comment that back when racers were running relatively springy steel frames, the narrow high pressure (tubulars) were still pretty great. As the industry has pushed us to stiffer, harsher frames and forks, wider tires at lower pressures are more obviously helpful.
You are spot on . This is the elephant in the room.
Steel frames being comfier is another cycling myth. Now marketing BS with the 'Steel is real'crowd.
Cycling About took frames into a lab to test. Tyre pressures have always made the biggest difference to comfort, with way behind that long flex seatposts and frame deflection being a non event.
@@JeremyLawrence-imajez get a QUALITY steel frame and see for yourself that it's no myth.
For me, the really important aspect of this is that the "suspension" you get from tyres is in another league compared to any kind of structural compliance from frame material. There's a reason why mountain bikers are running bigger tyres than they used to even though suspension has improved leaps and bounds at the same time. Cheers, Si
@gcn I don't know about modern mtbs but they were never about having compliant frames. The frames were built to be strong, the tyres did all the work.
Kona Libre CR gravel bike. OEM: WTB rims with WTB Venture 47 x 650b tires. For "road rides", DTSwiss CR-1600 rims with Teravail Rampart 38 x 700c tires. Both sets run tubeless.
I used to have 25mms on my old vintage motobecane from the 80s. Now i use a cyclocross bike as my all-in-one bike with 33mm tires. The extra grip and comfort, especially in rainy and wet conditions with random branches strewn on the road give me confidence to actually go faster, and bike more often when i might have stayed inside or taken the bus. There's just no contest between the two for me, 33mm or thereabouts any day
Same here. My CX is my road bike too and I stopped going to my summer 28mm road tyres after realizing my 5mm wider CX tyres were as fast. With more comfort and grip too. Win, win.
You have less grip on wider tyres in the rain. Why? These tires have a smaller contact patch and can cut through standing water more effectively, reducing the risk of hydroplaning. So you’d better off using the 25mms.
@@Excelbrains if you are hydroplaning on a bike then you will be breaking all sorts of speed records.
@@Excelbrains if you can hydroplane on a bike, then you will be setting new and inadvisable world speed records.
@@JeremyLawrence-imajez ha true, I meant just ‘slipping’ instead of ‘hydroplaning’.
@9:35 -- there have been fast, wide, supple tires for decades. I was riding Grand Bois 700x30 back in 2007. They just barely fit my road frame but, anecdotally, my fastest rides back then were on those tires.
The 28 Tires of 2017 are the 30s of today. Most tire sizes have become slightly smaller for the labeled width. Since the rims got wider.
Isn’t it the other way around?
@@InfiltrateIndustriesNope my 28 continental 5000-TL measured 1.2mm wider on my 20mm internal rims than the 5000S-TR that replaced them. It was like 30.2 for the 28mm 5000-TL and 29mm for the 5000S-TR. The continental 4000s were even wider than the 5000-TL. So manufactures downsized their tires a little bit, to make the difference between the labeled width and the actual width a bit smaller.
I use 4.8 inch ( 120mm ) on my own design road fat titanium. Love it, my favorite road bike.
But which tyre width was more fun to ride? I got excited by all these revelations about wide tyres and went up from 25mm to 28mm on my road bike (same tyre make/model, recommended pressures, modern carbon rims optimised for 25 or 28s) and was surprised that the ride was noticeably more dull and lifeless with the wider tyres. For me, the most important thing is that riding my bike is fun. After a couple of long rides to give them a good try, I gave the 28s away and I'm back on 25s and loving them. (For context, I'm 62kg and have been riding road bikes and cycle commuting on a daily basis for the past 20+ years.)
I’m about your weight, and have not regretted for one second replacing my 25 mm for 28 mm a couple a years ago. I would like to treat 30 mm if my frames allow it.
Agreed, I've always thought 25's gave all the comfort I need. And I've no intention of going to tyres that are wide enough to ride ver potholes without noticing them...
That is a good point - simple enjoyment will be variable by person.
Fun equates to a jarring ride and less grip and speed on descents? You have questionable intelligence. Also, wider tyres are faster on real world roads because of less vibration.
The dull is the best experience with wider tires. I am 95 kg and wide tires feels so dull, dull, incredibly dull
I have actually ran both the standard and the extra light. The sidewalls do weep a little at first but sealed and the standard set up easy tubeless with zero issues. I don’t ride anything super chunky so I have never worried about going with the endurance casing. The standard is still extremely supple, compared to other tubeless road tires I have ran and I feel are very worth it. I am a big fan of Rene Herse tires! These are my road set up on Enve rims and feel every bit as fast as the 28’s I was running
@timtuckett723 Which model are you running? Did you have problems mounting the extralights and how was your experience with punctures on those? Thanks!
Please, make the same test with UPHILL in order to see differences, thank you
As a heavy rider, I’m encouraged by these results🙏 but my beloved 2006 Specialized Roubaix comp will barely accommodate a true 28c. That aside, I’d love to know how each tire size perform (handle) on climbs and down hills with turns? I’d imagine there are performance differences?
What about staggered tyre set up? Like 26s front and 28s behind? Or 28s and 30s....and so on.
This is a good idea. The reason is the weight distribution when riding ( more weight on the rear wheel). You can use nearly the same tire pressure. The slighty smaller tire at the front wheel improves the speed at fast descents. On my 2 wheelsets I use 25/28 and 30/32 (for long rides).
It has been done quite often in time trialling and triathlon, where a narrower tyre on the front gives better aerodynamics and a wider tyre on the rear gives more comfort and reduced rolling resistance. In the back, aerodynamics and frontal surface area are less relevant.
Also mentioned by @dirkstaudt4341, the weight distribution plays a role. However, on road bikes the distribution is generally about 52% on the rear and 48% on the front. You can't use the same pressure if you're running for instance a 25/28 combination.
I run staggered - see my post for details and reasons
You cant measure 0.5 to 1 W difference in practice run like this.
We'll grab out lab coats and get testing 👌
Amazing stuff thanks GCN. Great vid for us common folk!
I appreciate explicitly covering the test methodology. Quite interesting results!
Glad you enjoyed it! Are there any other test you would like to see? 🥼
I have 32mm road tires/wheels on my CX bike that I routinely swap out in place of the gravel tires and they feel faster than my road bike wheels 25mm! Thanks for doing the research on this topic! ❤
They're all the same - what a surprise!
The biggest resistance is air resistance and 80% or so of that comes from the rider - so at constant watts the results are bound to be the same.
Of course tyre widths and pressures have an impact - narrower and higher pressures on the track and wider and lower pressure on bad surfaces or in the rain. They have an impact but it's second order compared to the aero drag from the rider.
But the idea that changing from 23 to 32 was going to turn us all into MvdP or TP was always marketing bluff that was for the birds.
Buy really cheap tires with classic tubes and compere to high end tiers. The difference can be quite significant
Yes, but what I don't get why came this only out now and in the past they rode 19mm and stuff? The "testing methods" are the same anyways no?
@@Dr-bob1337 not necessarily. I'm under the impression that there's been a much more scientific approach to everything related to cycling in the past 2 decades, from gear to physiology. Big teams and big brands are spending big money on research. Probably in the past it wasn't as easy because the technology to do the research wasn't there yet or was too expensive for what could be gained. It was easier to find ways to get away with doping.
@@Dr-bob1337- Cyling only met science in last 20 years. Pretty much all myths and superstition before that.
No-one ever claimed fatter tyres would get us rainbow jerseys. The claim has always been more grip and comfort with no loss of speed. The more comfort will however keep you going faster for longer because being rattled is fatiguing.
snoogled 32mm front and 30mm back into my old giant wich is supposed to have max 28mm.
Biggest difference I noticed was in corner-speed and confidence while descending.
Will the shop be selling the weather stations?
Great video Lads. In engineering we were taught more surface area contact the more power required to move an object, and there are formulas to calculate this. Less contact, less power required to move an object. So I've been watching all the videos regarding tire widths thinking how is this possible🤔 😂
Actually I think I can answer part of this. I’m not any expert but it has to do with the shape of the contact patch. The narrower tire let’s say 23mm at high pressure vs a 28 at lower psi has different contact patch. The 23 is long in a 12 to 6 pattern whereas the 28 has a stubby 3-6 patch. That’s how it was explained to me. But not sure what tire contact patch is bw 28 vs 35.
Still think there's more variables... My vintage ('84 Bianchi Sport) bike came with 700x25C tires, and in the late 90's I changed over to 700x23C tires. I can attest that these are a tad slower top speed wise... Except I can also attest they are faster when it comes to cornering. On 25C tires this bike does not like to turn - no matter how hard I tried, the bike would only turn very wide at lower speeds (even when having it leaned over far enough to scrape a peddle at the top of the stroke on the ground). On the 23C tires, I can carry more speed into and through out a corner with out the corner the bike wanting to make huge wide arcs. So perhaps geometry has a play in this debate as well? Anyways, I'm not going to advocate any tire size - find the tires that work best for you, your bike, your needs, and where you ride and use it. If the size ends up being 23C or 35C does it *REALLY* and *TRULY* matter? 🙂
I recently purchased a Pinarello F5 105 Di2 and it came with 28mm front tire and a 32mm rear tire (supposedly what Pinarello suggested to the company I bought the bike from). But I set it up tubeless with 28mm front and 30mm rear. Seems to work just fine, and I don't feel like it's any faster or slower than normal. Overall it's a heavier setup than my older Felt F4 with 25mm tires (with tubes), but it's a comfortable and nice ride.
I've used 25 and 28mm on my road bikes. With each jump in width you get a small weight penalty(20 to 30g's) so generally I go with the 25mm, and also these best suit my rel. narrow rims. And I like climbing. About a 70g/tyre difference from 25 to 32mm
I feel the same way I've gone between a 25-28 tire over the years. I'm on a rim brake bike so 28 is my max. I don't notice any difference in feeling between a 26 or 28 but I know it is lighter
Try to calculate the the time penalty of the extra weight up one of the climbs you do and you will find it's close to nothing with 140 g extra system weight. On the other hand improved rolling resistance will probably more than even out this weight disadvantage
...or less than a tenth of the fluid your likely to lose on a half decent ride.
Yeah all that is true. Most of it is just psychological and feeling good with one's equipment. Pro's throwing empty gel packets out of their back pockets before a climb isn't going to change anything either, but they still do it ;) I know with my own race results as an average amateur, that in the same races over years, on widely different equipment, that the only thing that really matters (assuming good tactics) , is ones form and fitness, and how many watts you can push on the day. This determines time and placing much more than anything else. Everything else is just window dressing basically unless you turn up on a Brompton or a BMX. Hence the endless equipment debates splitting hairs lol
I did discover one issue with wider tyres, at least in the winter on muddy roads - it became really hard work when I ended up with a thick layer of goo wedged between the tyre and the mudguard due to insufficient clearance!
Funny the call out to crosswinds with fat tyres and less far rims. This my my findings too when I ran a 35 on a 32 external rim. Went back to a 30 and the crosswind instability was greatly improved
same, I rode 32mm Schwalbe Pro Ones on my carbon rims (32mm external) and the crosswinds almost made me crash when i was hitting about 70kph, going down a big hill. Changed to 28mm and the stability improved drastically.
I’d be curious if 32s would work.
32s were also worse than 30s and 28s crosswind. But with 28s I cornered on the sidewall which kept damaging the tyre, so 30s were the sweet spot@@DB-sj8km
I was a traditionalist of 23mm for years, going on physics of less contact point equals less rolling resistance. I have yet to jump up big. I now run 25mm but may try 28mm next to just see and compare routine routes in Strava and Garmin to see any benefit on my Cannondale SSE with carbon Spinergy wheelset.
Very creative video idea and thumbnail GCN 😂 Source: Norcal Cycling
Ooooh, that’s a bit dodgy isn’t it?!
😂
This seems like the best argument for wider tires. I think you touched on an interesting point that until recently, wider tires were only available in lower performing configurations. I would venture that on a rougher more common surface that the wider tire would provide a notifiable advantage. A higher speed test would be interesting, to compare Aerodynamic advantages or disadvantages.
How will it be for climbing though?
I'll change when my tires needs to be changed and at that time, I'll concider a wider one.
makes nearly no difference, altho theyre a bit heavier. they are faster especially when the roads get worse. also a larger surface gives more grip on like wet or slippery sections when making big power. also descending will become better on the wider tires.
Can't see that wider tyres would make any difference for climbing
@@Markhypnosis1because they are heavier
@@Pablo_Coach 100 grams won't make any difference.
@@Markhypnosis1 on rotational weight it makes significant difference especially when You often slowing and accelerating, like crit racing
I've been running 32 Conti 5Ks front and back on my Cervelo S5. It's way more comfortable than the stock 28s. Cervelo says 28 is the best aero match for the Reserve wheels in front, but I haven't noticed a difference in speed, just comfort. I've just gone down to a 30 in front to save a little weight, but it feels about the same as the 32 so I may go back up. I'd certainly rather be on 32s in the rain.
My gravel bike has 35mm on it and mostly ride it as a winter bike on the road. It's so comfortable.
Sounds like an armchair of a bike 👌 We mean this in the best way possible
I used in the past 5 years 32mm tires (schwalbe one, gp5000, gp5000tr, pirelli next), i really liked it, because i used sometimes for light gravel. Last time i bought 28mm michelin power cup, and i enjoyed it the most on asphalt. I guess this is the most important, which is the most enjoyable for you. Anyway, the rolling resistance tests with compansated pressure show the same… very similar watts.
There one more thing to count. with the 35mm tire when you do a full rotation of the wheel you go further than the 30mm and the 26mm tire. So for the same RPM you go further.
and you have slightly more pedal to ground clearance when going wider
I'm currently running 42mm slick Cannondale/Panaracer tyres on my Slate for commuting. I feel they are as quick, if not a smidge quicker, as my 30mm Hutchinson Fusion5 on my Synapse. And comfort is amazing!
Physics says the main difference will be in acceleration due to inertia of a bigger tire. But even 35mm is still a thin tire if we view it objectively.
I did some rides last year on my gravel bike with 35mm smooth (almost) Panaracer tires and then some with 32mm Contis. They measured 37mm and 34mm respectively on 25mm IW rim. The comfort was amazing. This year I went back to my road bike with 28mm tires and they just feel too harsh. So I’ve upgraded the wheels to DT ERC with 22mm IW and just mounted 30mm Contis on them (31mm wam). Comfort is much better, descending and handling are more confident too. The way I see it - there’s no reason whatsoever to ride anything less than 30mm.
All the people that say their 23/25mm tires are faster - they are not. They just feel faster because at high pressures they are less spongy. So you feel your bike trying to jump in front of you with each pedal stroke. But it’s just a feeling which, apparently, does not translate to actual speed gains.
23 : Regular roads
25 : Winter or Belgian roads
28 : Paris Roubaix
30 : Gravel
32 : Cyclocross
35 : Rescue Buoy
40 : Fragile ego coffe brake sunday warriors in full Rapha Kit
32 has been my go to. 28 feels faster, but that is almost certainly just a feeling because of more feedback and the perception of a twitchier bike. Very cool. I much prefer the comfort of wider.
My prediction is that road bikes will settle to use 30-40mm tires and anything above 40mm will be called gravel.
Also the internal rim width will settle between 25-35mm depending on the width of tire used.
This season I am putting 30mm internal width aero rims with 34mm tires on my bike and enjoying the comfortable and fast ride.
I just got a pair of 30mm pirelli race tires with a new used bike I bought, haven’t tried them out yet cause I’m still hitting the gravel hardest right now, but I am excited to give them a go later this year, big jump from the 23mm I was riding
Fascinating! I'm still on 25c /o\ But to be fair, I don't think wider tyres will work with my 2009 frame and rims
Hi Darren, I've got a 1998/1999 Cannondale R800 alloy frame/carbon steered. I can just run 28 conti 4000's in this frame, clearance on rear dura ace rim brake a few millimetres and on seat post. Maybe a mates got some 28's you could try? It made a comfort on my old girl much better. But it's what you like and prefer ultimately!. I still think I'm faster on 23's/25's than science proves otherwise l!😂
That's the beauty of modern frames 🙌 Do you think that you would ever upgrade your bike so you you could run wider tyres?
@@gcn for sure. I'd like electronic shifting too. Just waiting until I have the funds - and something I want is available in a colour I like 😂
On my last bike, I ran 25c tires, but the wheels (vintage Giant TCR wheels) used carbon spokes. they were SUPER supple. I now have 30c Conti GP5 TR tires on my SL4 Roubiax with the stock Roval CL40's. They run a maximum of 75psi, and they feel TREMENDOUS.
Over a route I ride regularly which is 29.4 miles I am consistently quicker all the time on 23ml tyres versus 28ml tyres for reference roads are average and my weight is middle age spread 😅
By how much? On exactly the same bike and wheels? Is your power output the same for each ride? same wether conditions, clothing, and rider position, & total weight?
There are a lot of variables, but nearly all tests such as those by GCN show either negligible speed / power difference or a small improvement with wider tires at lower pressures.
Your results would be an outlier, so maybe your test methodology is flawed?
I only have the one bike so all I do is change the tyres it’s normally about 5-10 minutes the time I notice it most is when I swap my tyres to wider ones for the winter same make brand just wider
What bothers me is that advocates of narrower tires are being characterized as climate change deniers. Everyone trusts the science, yet the data that exists is inconclusive. Like the drunk looking under the street lamp for his car keys, when asked why he was looking there, he replies “Because where the light is!” … “Garbage in, garbage out.”
One thing I notice is that they're on a circuit, which is very different to real world use. I suspect where you'll notice a bigger difference is in things like acceleration from a stop, which is important when out in traffic, where the weight of the tyre becomes more of a factor.
Also, I’m not running tubeless so I’m not running pressures of like 60 or 50 or 40 or whatever they are which probably makes a difference as well
Si, once again my friend, you didn't let me down. You did the tests, and the results showed that the 35mm were marginally the fastest, and you already know that they'd be the most comfortable, and yet what did you have to say? "I still wouldn't put those on my Pinerello!" Good for you! Never let science stand in the way of you thinking you look cool.
Meanwhile, for the rest of us, put the wider tires on your bike and enjoy the benefits of less rolling resistance and a more comfortable ride.
28mm on road bike and 38mm on cross/hybrid....still getting used to lower pressures grew up in the eighties using 120+psi at 23mm on the road...interesting and much more comfortable riding, after watching your previous video's started exploring pressures ...and yes not much difference in average speed although hybrid is a heavier, bigger frame than the road bike so a bit slower anyway..... am also really enjoying using better compression clothing as my bones get older so much useful and comfortable new kit ...thanks for your insights have a great week
Rene Herse makes a brilliantly supple 35 tyre. And yes, that is what i run on my 3T
Rene Herse getting lots of love 👀
Which casing do you use? And what do you think of them?
- Extralight (most supple but kinda puncture prone)
- Standard (slightly stiffer and not so supple casing, more affordable)
- Endurance (same thread for casing like extralight but more dense and therefor slightly stiffer, more puncture resistant)
I'm also looking for the 35C one (Bon John Pass) and wonder which casing to choose. At least I don't want waste my fun and time to punctures, but wouldn't slow down with a tank tire.
A friend of mine got the Extralight and put some effort into it with sealant just to seat the tire on the rim and for sidewalls bleeding. Probably 80 ml just for that, plus 60 ml for possible punctures.
This would lean me more towards the Endurance casing (overall effort, weight, safety to keep riding) while seeing no benefit at all (beside money) for the Standard version.
I run the slick 38mm Rene Herse tires tubeless on my road/light gravel bike and love them. With the endurance casing.
I’m very excited because I just ordered a new bike with clearance for 45mm tires. I’m planning to run 40mm with fenders in the winter, the switch to my deep section rims with 30mm tires for dry days and fast group rides. I’m hoping I get similar results and then I can ditch the “road” rims and just run big pillowy tires all the time!