My Trek came with 32mm from the factory. I was also biased, that I "need" narrower tires. I have ridden the 32 Mill for ~2000km, switched to 28 mm for 6000km now and decided to go back to 32mm. I haven't seen any improvement in speed or anything like that with the 28mm but the comfort of the 32mm is so much superior that I prefer that. My usual rides are somewhere between 80-100km with 28-30 kph avg. And yes I am way too heavy to consider myself a "real road bike rider" :D
My Domane came with 32mm but somehow the tyres were to wide for my liking. I dunno why but this really affected my motivation to ride. So I upgraded to Carbon wheels to compensate for the racey feeling. Definitely didn’t regret it.
My allround bike came with 32mm tubeless and I fell in love with them. The differences with my previous 25mm clinchers is massive: - way more comfortable to ride on - Can be easily inflated by a small hand pump because of the lower pressure needed. - Can handle light gravel comfortably meaning you can add extra gravel tracks to your route. - Can also handle rougher gravel without risking a flat, but it wont be very comfortable. - feels more stable when turning All in all I'm very happy with it. So far I've ridden more than 3k km with it without any flat.
My endurace came with a 30 up front and a 32 in the rear. It’s 95% used for tarmac but the roads aren’t the best and I’ll soon be running 35mm front and rear. For me the comfort and confidence a few mm’s bring are the difference. Im also aware that I’m never winning the tour or going pro so I don’t need to lie to myself and run 25’s just to suffer.
I believe that after 32mm, the law of diminishing returns kicks in on a road tire width. I mostly ride a gravel bike set up for road: Enve 3.4s rims with Rene Herse 35mm slicks. At 195 lbs, I run 110 psi - hard. Very comfy ride, but slower than my road bike. Much slower. My road bike has Mavic Rys rims with 28mm Conti 5000s. I run them at 120 psi. It's a different world. Huge acceleration advantage for the road bike. Climbing is vastly superior on the road bike. And I have no doubt that it's the different tire width, not the different geometry, that accounts for MOST of the difference in speed. I'm going to buy some 32s and put them on my gravel bike. My bet is that the performance difference will narrow vastly between the two machines. Any takers?
@@MrIsaac-dh3uh let us know of the results! i also have a gravel bike with 42mm tires, and contemplating buying a road bike.. but if putting 32 mm tires on gravel bike is a good enough improvement - I'd rather go with that
For the past 3 years I was riding 25, and last week I changed to a 30mm. I am so happy I watched your video, it’s much more comfortable, not affecting the speed, acceleration is amazing. Just more fun. Thanks Simon and GCN
Are you using rim brakes or disk brakes? I'm wondering if 30mm tyres (looking at the schwalbe G one speed) would fit the Shimano 105 R7000 rim brake caliper. Is there anyone who tried it out yet? I know the spec sheet says it is compatible up to 28mm, but they do not make certain tyres in 28mm.
I was happy with 28mm until I accidentally ordered 32mm tyres by mistake, best mistake I've ever made for biking. The performance is the same for me but the comfort is so much more on long and quiet back country roads. I'm converted.
Back in the 1990s, I was running 23 mm and 25 mm tires on my road bikes, and my racer friends were telling me I should be running 18 mm tires. Now, I'm still running 23 mm and 25 mm tires on my road bikes, and I'm being told I should be running 28 mm or 32 mm tires. Of course, back then I was being told I should have triple chain rings on my road bikes. Now, I'm being told a single chain ring is just fine.
Well when the kassette was 6/7/8 speed a triple chain ring gives enormous advantages. When however you already have a kassette that has 10 gears or even 11/12, the advantage isnt as big. A 1x setup in the 80s with 6 gears has half the gears as a 1x now with 12 gears. So while im not on the 1x train, rather the 2x, it makes sense for many areas.
@@kaseycarpenter73 i had an mtb now i have shifted on a hybrid bike which has 28 c tyres, on roads it is fantastic, i feared that on rough roads it would have less grip and uncomfortable, today i rode it on a hilly unpaved track, i never felt that the tyres have less grip or uncomfortable
@@gulmuhammad5158 Nice. I have an allraod that can take up to 50c tires. So when I want plushy plush, I put on my 650bx50s and steamroll over everything -I mean literal potholes, lol. When I have the zoomies, I swap those out fo the 28mm deep dish rims, which, with inserts, I can run at about 70psi and still manage some level of comfort.
@@prokopf-9332 The number of gears in the cassette has changed, but the gear range for road bikes has remained about the same. You could get 11-34T in a Shimano 8-speed cassette, and you now typically get the same in a Shimano 12-speed cassette for road bikes.
I'm currently riding 28 mm which is the thinnest I've ever ridden. Before that I was riding a hybrid bike with 35 mm. I was expecting the 28 mm to be a really rough ride, but actually have no problem with it at all. Find them perfectly comfortable. That's probably because even when I was riding the 35 mm, I was doing so almost exclusively on the road, so they were always held at relatively high pressure, and so I'm already used to that feel.
I just changed my 28mm to 32mm and found no difference in speed but, ride comfort was absolutely superb! I accidentally climbed a 16% to 18% and took the climb much better than expected. Hills were no bother, speed consistent and being a 110kg belly buster I thoroughly enjoyed the ride. Sticking to my 32mm tyres - Schwalbe Pro One TLE Addix-Race Evolution, awesome! At 62, I gets me thrills where’s I can! 🤪
Just bought my first road bike, how would I know if I'm able to fit 32mm? It currently has 25c, not a lot of clearance with the rim breaks but can that be adjusted?
Air resistance is proportional to the square of velocity. Hence, required _power_ to maintain a velocity is proportional to (velocity ^ 3). Reason, you overcome the air resistance in shorter time, hence the square of velocity, times the velocity..... Consequently, the speed difference between 28mm and 32mm driven with the same power, is only one percent, 0.4 KM/h. Assuming of course the 10 watt difference as mentioned in the video. The small speed difference is relevant for competion, but for recreation? For me, comfort is more important. I moved from 23mm to 25mm back in 2008, moved to 28mm in 2010.
45psi! Wow, I remember people routinely pumping up to 120psi with 23mm tyres a few years ago. I never thought there was much point in that as it was just uncomfortable and skittish, and I felt so vindicated when Schwalbe did some research in perhaps 2010 and concluded that lower pressures (up to a point) were more efficient because they allowed the the carcass to absorb micro-bumps without vibrating the whole bike (which of course takes energy) - the point that everyone seems suddenly so aware of.
I use about 85 psi on my 28c. I'm not confident in avoiding a pinch flat going lower. I'd love to try 32c but 28c is the most that will fit under my 105 brake calipers
My Scott Addict comes with 32 mm Schwalbe One tube tyre and I run 53/58 psi F/R. Far more comfortable than my older bike's 28 mm at 70/80 psi with no significant loss of speed.
my dads bike has 32's and i borrowed it to climb in the mountains, i didnt notice them being slow at all, in fact on the descent i cornered like i was on a motorcycle, now i want 32's
Very interesting video. I ride long distance, sometimes into ultra-endurance (circa 200km) and I opted for a 32mm. Reason being that I wasn't trying to go as fast as possible, I wanted to go as far as possible and the argument was that comfort over an 18 hour ride would be better than an extra 1 or 2 kph over the same distance. The beauty about this of course, everyone can choose what works for them!
Mark Beaumont in all his endurance related videos, podcasts and books claim anything over 100 miles is ultra. I'd say he's fairly well qualified to pass judgement. I am not tied to a single definition, in fact, if someone said 200km was bang average I couldn't care less. It's about getting out, turning the pedals and smiling. So if I ride 200km +, whatever the definitions are, I ride a wider tyre for comfort. That was simply my point.
@@Kobe404 well, I stand corrected. I'll not disagree with Mr B. I'm a fan of 35mm tyres for long (over 200km) stuff, and night riding. For quicker paced stuff of 200km I usually use 28mm tyres.
@@hectorkidds9840 the beauty of it is, we can all go with what we think works best. I just did a long ride of around 250km for charity and went back and forth on tyre size for ages. Eventually settled on the 32s because I'm lazy and couldn't be bothered switching to the 28s 🤣🤣🤣
A few months ago I changed from a 25 mm to a 28 mm Continental Grand Prix clincher tire mounted on a Vision Team 35 wheel. Beter cornering, less pressures, a bit more comfort, better on those small gravel roads when 'necessary', and much better looks. Love it. Go for that wider tire when possible is what I think.
I replaced my aluminum wheels with carbon wheels and went with the recommended tire size which were thin. It vastly improved my ride, but I recently purchased a look with thicker tires and was astounded at how much more comfortable the ride was. Given that I am a casual rider, I prefer the comfort.
Are you using rim brakes or disk brakes? I'm wondering if 30mm tyres (looking at the schwalbe G one speed) would fit the Shimano 105 R7000 rim brake caliper. I know the spec sheet says it is compatible up to 28mm.
28-32mm tubeless are a nice sweet zone for me on UK roads, fast, comfortable and low rolling resistance (P zero race tlrs or 5000s tr) on hookless rims.
I ride 28mm@front (more aero) | 32mm@back (more comfort). Remember to take a look at your weight distribution on the bike to give each tire an individual calculated tire pressure. Would be great see a video about weight distribution / tire pressure and a mixed / individual tire setup for the front and back wheel.
I've got the same 28 front 32 back just because that's all the bike shop had day before a long bike trip .what pressures do you like to run I'm 81kg run 80psi but looking at this vid make.me think I'm running too high and was also think bout swapping back to 28 but the 32 is comfy
@@chrisswan3986 That depends on the inner rim width and whether you have a clincher, tubular or tubeless setup. At a system weight of 90 kg and for a tubless setup with an inner rim width of 22 mm i would recomand 65 psi at the front (28mm) and 59,5 psi at the back wheel (32mm) for a dry road surface.
This came at the perfect time. I have a Trek Checkpoint that still has the stock 40mm gravel tires that need to be replaced, and since I ride it exclusively on the road now I was looking at going with a 28mm or 32mm road tire. I currently ride between 15-16mph over 20-30 mile rides so I think the 32mm will suit me better at this point.
Go for the 32C tires. I also have a Trek Checkpoint SL6 which I use mainly as a road bike. I ride at about the same speed averaging 40 to 60-mile rides. We have significant hill climbs all around where I live. Switched to Hunt 35 X-wide hookless wheelset with 25mm internal width and Continental GP 5000 S TR tires. Very noticeable difference. You will be much happier with the 32c tires.
I’ve got a Checkpoint and have two wheelsets, one with 32mm Maxxis Refuse and they are great for everything. The original Specialized Diverge (2016 ish) gravel bike came with 32mm tyres as standard.
@@AndyPaul-wr5hm Hi Paul, isn't 25mm too much for a 32mm tire? Could you measure how wide is the tire on your wheel? Thx I have GP5k 32mm on 21 inner wide wheel and is 30.5mm wide when measured.
@@petertapaj4859 There is a table on the Continental 5000 S TR website that shows the max rim width supported by the 32C tires is 25. I don't have calipers to measure the tire width on the wheels but I can say that I have ridden over 275 miles and 21k vertical ft with this setup with no issues.
I moved from 28 to 32 but kept the same tyre pressure in the 32 that I was running in the 28. The research that I carried out suggested lowering the pressures in a wider tyre if you want better comfort, or keep a higher pressure in the wider tyre for lower rolling resistance/faster speed.
I predominantly ride audax and touring. Love my 32mm slicks for combination of comfort and speed but currently run 35mm slicks because I prefer a bit more rubber under me when the bike is loaded. They are perfectly fine for the average speeds I ride at (21-26kmph) and can handle all British road surfaces plus bridlepath gravel.
We ride a tandem and it turned out that our otherwise perfect 50mm slicks (Schwalbe Kojaks) were weakly protected against punctures. A protection belt inside a tire is a nice thing but these extra millimeters of the tread are just necessary to do the job.
@@PrzemyslawSliwinski that’s a pain. I run Panaracer Gravelkings and found the tan walls look lovely but puncture too easily. The all black however seem to be pretty bombproof.
I did ride on 23s for years then moved to 25s. Then tried 28s for three years. I found 28s to be noisy, cumbersome, dead feeling. Moved back to 25s and the ride just feels different - better, more enjoyable. BTW so glad y'all keep reminding us to just be out there. Good job as always.
I tried one winter on 28mm tyres (2004). They were more comfortable, but like you I found them to be sluggish and dead feeling. Needed to change down a further gear also to get up the hills. Ridden 23 and 25mm ever since and am happy.
I agree with you. I find the wider tires feel slower. I rode 23 for years then moved up to 28 and back down to 25's. Used the same tire brand. I am not sure if the wider tires were actually slower but the bike handled sharper and felt more responsive and faster. Also I felt that there was better road or surface feel with narrower tires.
Interesting video, thanks! Currently using my gravel bike as a do-it-all bike with two wheel sets. On the road wheels I run a 32mm Conti GP5000 tubeless, works brilliantly, super comfortable and extremely forgiving when riding gravelly cycling paths. Not concerned about speed too much, came to accept I am very slow ;-)
I specifically remember during the 2022 Tour de France that many teams were using 26mm tires (except for the cobblestones of Paris-Roubaix). 25mm are perfect for me. My brother rides 28mm, and we always have identical data after 40-50 mile rides.
Vingegaard has been using 24 mm in 2023, Pogacar as much as 32 mm. Average TFD is 25-26 mm might be. I presume they use different tyres depending on the stage, bike choice, etc.
At 10:32 Si says, "28s at 40k/h were statistically better....10W more efficient". The table at 10:16 regarding average power required on 28s at 40k/h was 343.0W and at 10:21 the table shows the average power required on 32s at 40k/h was 343.5W. I only see a 0.5W power difference. Can Si show his math? Or was this a typo on the tables?
Yep...I did it on my 2022 s-works tarmac sl7 and now on my 2023 trek madone slr...28mm in the front and 30 to 32mm in the rear...speed & comfort all day
Beginning at the 10:17 mark, Si claims that the 28mm tires are 10 watts in savings at 40 km/h over the 32s but the data illustrated says the 28s were 343.0w at 40 km/h while the 32s were 343.5w. That's only a half watt, not the 10 watts claimed as being the advantage at the higher speed. CGN, am I missing something here?
@@nctrns You won't get a reply because the whole premise of the video doesn't take into account the complete inconsistencies of the road. This evaluation needs to be done with the wheel on a weighted rig on a rolling road dynamometer.
@@fredbrackely You have missed the point of the video. A rolling road, even with the tarmac simulation surfaced roller, does not replicate the inconsistencies of road surfaces and how different-sized tyres and pressures deal with traction loss reduction as tyres widen.
I remember fitting 26" x 4.00 to my bike, and all I can say is that the difference was incredible, it completely smooths out bumps in road, and gave me a little bit more confidence on the occasional gravel track.
I used to switch from my 28mm road tyres to my 32 CX tyres when roads got slippery in Autumn each year. Then several years I realised I didn't go any slower. Not used the narrower road tyres since. Plus as I tend to go off road a lot even with the 28mms, I was even faster with the fatter, grippier and more comfy tyres there too. Less rim smacking too. I switched to lower pressure even earlier after doing bike comparisons and discovering the lower pressure tyres and as a result way comfier bikes were faster. Wider tyres also need wider rims to prevent a lightbulb shape which is not good for aero benefits. The difference in this test could be simply down to that rim width aspect.
Very informative. I am definitely not a racer but I do like to go as fast as I can. However, comfort is the main factor for me & there were 2 stand out comments. At 04:10 Simon emphasised the importance of vibration loss - a real world issue. Then at 10:30 he said that the 32mm tyres were "way more comfortable". These are the key issues for me
I upgraded my endurance bike's 32mm stock tires for Pirelli's 28mm Cinturato tires (for a mix of better performance and puncture resistance). Something that is not mentioned in this video is that stock tires are often not the best and that switching for higher grade tires (32 or 28) could make a huge difference in ride quality. I saw a noticeable difference in cornering, handling and Strava PRs. Long story short, the tire quality can make a big difference.
A good point to make. I just upgraded from Bontrager 1 to Bontrager 3 Went from 32 mm to 28 mm. I only have one 33 mile with the new tires. Time will tell.
@@2006zo6vette how they are ? 😮 I am gona give the 28mm tyre a run since i always run 25mm tyre hope it will help my cornering handling and confort without affecting the speed !
I like the new trend in modern road bikes, coming with room for 34-35mm tires. Makes the bike much more versatile, and most people don’t have perfectly smooth roads to ride regularly.
I've been running 32mm Hutchinson Sectors for a few years now. I'm a 58 yo tall clydesdale. I tried these as winter tires initially, but liked them so much I never went back to 25s or 28s. I think I'll try the Vittorias at 34c when I next buy tires. My bike has clearance for 35s.
I mention this video to fellow riders in my bike club, as the whole philosophy around tires and tire pressure has come a long way! I remember 15 years ago being taught to fill my 25mm's to the maximum air pressure! As my main bike, I now have a T Lab R3 Omni, and ride it for both road and medium gravel rides. Using 35 mm PanaRacer tubeless 'slicks', I have no problems keeping up with my group. I'm in the 24 - 26 km/hr classification, about 80 km 2 - 3 times a week with road, or mix with about 60 km gravel rides. Much smoother ride, do need a lot more cleaning with the gravel rides, and much fewer flats (but I have put an innertube in on a flat recently!). I know others doing the same thing. Was thinking about going to 2 wheel sets (28 mm and 35 mm), but this works fine for me.
running 35mm Rene Herse tyres for 2 years now on my Canyon Endurance and I love it :) only problem I found is that is getting a replacement innertube ad a event.... because I was riding 1 month outside on my racing bike this spring and was bikepacking for 3 months after that on gravel:) I didn't get tubless setup this year..... but I rode the Amstel Gold event race and got 1 puncture so ad the first stop I got an extra innertube..... they had only innertubes for 23mm..... and you guesed it I got another puncture..... the 23mm innertube.... barly fitted and got blow out in 10km..... my mates all ride 25/28mm and well those dont hold out in 35mm to good eather..... had to bail out of the event 15km bevore the end still running these tyres because I love the smoothness of them so much but running tubless again. and run with 2 spare lightwight innertubes in my pocket now, because my mates still haven't seen the light :D
I love the 35mm Rene Herse Tires! I used to use 32mm Conti GP 5000s, but I loved the speed and feel of the Rene Herse 35mm, I switched. Supple, smooth, fast - plus I can ride anywhere with them.
I bought my only road bike in 1994, it came with 25mm wide tyres. That was so uncool after one season I've built myself new wheels with 19mm Vittorias. How times change.
@@TimFerber Back when I started racing in 1970, as a 14 year old in the intermediate class, some of the silk (and cotton) casing/latex tubed, high end tubulars were even 17mm wide, and a few of the top track tires were even narrower than that! We used to pump them up to 145+ PSI, and they rang with a sharp ping when you flicked them with your ring finger. LOL The sole exception was the Clement del Mundo 'training tires', which were an unheard of at that time (for a road tire vs. cyclocross tires) 26mm wide. They still had a fine silk casing and latex tube, and were quite responsive despite their perceived excessive width for that era.
As someone with disc issues in my lower back, I switched over to 32mm for the added shock absorption since it means I can ride comfortably for a much longer distance, and I don't deal with pain the next day. I was going to go for some super swish carbon seat post to help smooth out the road rattle, but these did the trick at a fraction of the price!
@@fVNzO Completely unrelated to cycling, so no worries! Far too many years of a physical job that took a serious toll on my spine, eventually causing multiple discs to degenerate and collapse. Cycling has provided me with an excellent source of exercise that has made a huge difference in my quality of life. I have less daily back pain now then before I started cycling!
My new Trek Domane came with 32mm tubeless tires. My previous Domane had 25 mm tires with tubes. I ran the 25mm tires at 100PSI rear and 95 PSI front. I run my new 32mm tires at 60PSI front and 70 PSI rear. I have to say that my new bike with the wider tires is much more comfortable to ride even considering that the new bike has some "suspension" built into the frame. The new bike is also considerably faster than the old bike. The new bike with the wider tires is also much more stable at speed.
Interesting report. I'd think that i would never go any bigger than my 23mm, but then again 90% of our roads in my area are pretty silky smooth. Bring on the speed!
After decades of riding 700x23c tires at over 100 psi, I figured the wide rim and wide tire setup (700x32c) on my 2020 Trek Domane SL7 was a marketing gimmick. However, I'm now a believer in the wide rim / wide tire package and can't imagine going back to narrow tires for endurance and training rides. I feel so much less fatigued at the end of a ride and I've been able to ride over the nastiest of roads and gravel w/o flatting (partially due to a tubeless setup as well.)
I have had this discussion with my cycling friends while group riding on multiple occasions. I use 28mm tires on my road bikes which I inflate to 80psi (I'm 84 kg). This combination works great for all "real world" riding conditions. When we do hit the occasional new and super smooth tarmac, then I think narrower/harder tires are great, but even in those rare conditions I don't feel that my wider, softer tires are much of a disadvantage. Of course, there's no comparison in comfort. The wider softer tires make for a much more comfortable ride in most conditions, which if I'm honest, has become much more important to me as I've gotten older. Great video and I love your real world testing!
I run my 28s at 80 psi also. I tried them at 65 and 70 psi at my tech’s recommendation, but get much better performance with enough comfort at 80 psi. I’m 75 kg
@@ancientfifer I'm 87 Kg and also uses 80psi on 28mm Zaffiro Pro Vittoria tires. I'm not riding tubeless. I've tried 55, 65, 75, 80, 85, 90 and 110 psi already - After 85 PSI the bike receives all the vibrations from the tarmac (and holes + imperfections) I'm used to ride - it becomes a shaky ride with tingling hands. With lower pressures than 70 psi, it seems that the bike get stuck into the ground. The observations were based on my personal experience and feeling, so means almost nothing in science terms.
@@regisateparece yes, I have experienced that "stuck to the ground" feeling at 65 and 70, although its comfortable ride. I'll run at that pressure on a casual recovery ride though, with no big climbs. Happy riding!
@@Gma7788 That’s a misconception. The tires has a U profile like in superbikes. The area that touch the tarmac is really narrow compared as the total width. So entering in the corner, you’re able to bank left or right and turn as motorcycles, without turning the front wheels. That’s the only way to turn when you’re speeding (in bikes or motorbikes). That’s why the wider tires doesn’t bring rolling resistance proportionally to the width - they’re U Shaped.
Am running 28 on my tcr, very pleased with their performance and comfort.. in this test, the differences in the psi are much greater then their measured speed differences. I wonder about how the actual tire deformation from making contact with the road surface affected the results. Wish they’d done a 3rd run with 32 at higher pressure : maybe mid point ?
Loved the conclusion at 9:40 that it doesn't matter what width tyres you have the most important thing is you're out riding in the first place! Awesome! (btw I have 32 tyres but I'm motivated to experiment with softer pressure!)
Did my triathlons and an Ironman on my new Michelin Power Cups 28 mm, tubeless this year. Very impressive, fast, sticky and puncture proof tyres. Didn’t notice me becoming any slower, though wayyyy more comfortable ride. Pressure is at 72/74 psi but I am a heavier rider.
When I first rode a road bike 20 years ago, I put on 21 for one year and then progressed for 23 about 15 years. For the last 3 years It is 25. It is still on rim brake alu wheel about 1.7 kg. I have no choice as more and more online tyres come with 25 minimum and it's fine by me as I don't notice much difference between 23 or 25 as I am a senior citizen rider, travelling at 25-30 km/hour.
I tried 25 instead of 23 and defiantly noticed the différance, the 25 rubbed inside the mudguards, defiantly not changing 4 perfectly useable vintage steel for modern plastic landfill crap.
l ride two road bikes one with 32s @80psi one with 25s @100psi . l can go lil faster on the 25s but l prefer the 32s more BTW the difference is only 3km/hr on the same stretch sprinting :)
I've been riding on 35 mm Schwalbe Maranthons for over a month and I am really enjoying the increased comfort and stability, and I'm not really seeing a drop-off in performance. One thing the increased stability gives me is confidence. I feel safer standing on my pedals when I want to really put down the power, and also faster speeds feel much safer, so I'm less inclined to feather those brakes, even on relatively rough roads. Yes, technically my 28 mm Continental Gatorskins are faster, but the difference is so slight I don't really miss it. Mind you, the speeds I'm referring to range from 22-33 mph, so there may be some +33 mph performance I am just not aware of.
The chart shows 343.5 watts for 32 & 343.0 for 28. How is that 10 watts better? Isn't it only one half? I'm pulling of the 32s if they're costing me ten!
Wow, now this was some seriously valuable science! Thanks lads for doing this (and for making it utterly entertaining as usual). I think I'll stick with 28, but the promise of better comfort with 32 is enticing
@@discbrakefan up until 28mm, there has never been a problem with rim brakes, the only problem was some frame manufacturers leaving too little space between e.g. the rear forks or seat tube and the tire.
Thank you for performing a scientifically sound experiment and showing/testing two important points: 1) That gathering a statically significant sample size can be boring but necessary. Wouldn't be surprised if Alex really was that bored by the end. 2) Testing at a speed the average person rides at. Too often companies make claims at 40 km/hr. The only bit that was amiss is Alex wearing shirts with a lab coat.
A very intuitive video that raised a huge number of very informative comments. I ride 80-100+km on rather imperfect tarmac with 25mil clincher on both wheels which are way more comfortable than the previous 23s, but seriously tempted to go to 28mil on the back wheel as a start. Thank you all :)
Great, informative video. However, the results might be slightly skewed by your suboptimal tire pressures. The Silca Tire Pressure Calculator says you should be more like 61 PSI for the 32mm tires and 76 PSI for the 28mm tires.
45 psi in the wider tire, i agree with you. I end watching the video after 2 min and 50 seconds lol :) why do people always do unserious test of these things. Only to get a lot of comments. And why not try the same psi in both tires?
@@allemyr Because GCN isnt really tesing channel, its more of a fun based channel and commercial based channel. Most of these tests feel really rushed or biased which is sad, beacuse it takes away also lot of its entertainment. Plus most of these "tests" are sponsored so you cant really show that theyre new extremely overpriced product is actually as good as the old one.
@@alexmichl3137 Yes I agree with you its entertainment. And I also agree with you that the dumb choice to setup these tests takes away a big part of the entertainment. When I start to watch tests like this I always get some sort of headache early. Hope all people get that for viewing stuff like this :) The topic is super interesting about tire pressure and tire sizes. The test methology is so dumb so I won't comment the test in this video. Best! / Karl
@@danielhall3895 Sorry but running 45 psi on 32 mm tire is just extremely underpressured, thats recommended pressure for chunky mountain bike tires. Plus it doesnt add weight, as air weighs basically nothing in such a small volumes. Yes ultra high pressures create stiffer bumpier ride, but underpressured wheels on the other hand create wobly unstable ones. Thats the whole point of having ideal pressures for tires. As a guy up mentioned the ideal pressure for these conditions is around 60-65 PSI for 32 mm.
Yes, and he also SAID the same numbers, except at the end he didn't state out loud what the 32mm 40kmph watt avg, they just showed it on the screen. Another commenter asked the same and CGN rep said the 28kmph wattage was 331w, completely different to what the guy said in the video. Really, when you make a video specifically to talk about these numbers, shouldn't the editor check and double check the numbers and what gets said before actually posting it to youtube?!?!
I feel the same dogma that pushed us into 22mm tyres without any scientific thought still prevails in clipless pedals. Would love to see you challenge some of what I see as myths around SPD vs SPD-SL. What has the size of the pedal got to do with contact area with your foot when both affix to a shoe (which is the contact point and SPD shoes tend to have a metal plate at this point)? Why does a shoe need to be bone stiff all the way to the heel for power transfer? Where’s the power loss in flex and how much power are you putting down anywhere but the ball?
It's less "without any scientific thought" and more of a greater understanding of the physics behind what we know about tires. In addition, we have a greater variety of rubber compounds to use on tires, giving us more options than what we've had in the past. As for pedals, from an amateur's eye, it would seem that road pedals are designed for long rides without too much variation in direction and terrain or too much getting off the bike (if at all). Road biking is all about repetition and optimization, after all. On the other hand, MTB pedals are designed around multiple surfaces and the inevitable hopping off the bike and walking/running down difficult terrain. Hence, why cylcocross bikes use MTB pedals and not road pedals. It's not "which is more effective" but what's more effective for which activity? It's like comparing running shoes versus trail running shoes.
@@zenspeed404 I don’t disagree they are designed for a specific purpose, I’m just asking the question are SPD-SLs really any better than SPDs for road use. I’m happy to be proven wrong but i’ve not seen anyone go in depth on this. My sense is people talk about power transfer and platform size when nobody has actually tested it. For e.g. we all know flexible frames are not any better for power transfer, simply sprinters prefer the feel and security of a stiffer frame. Perhaps people prefer stiff soled shoes but do they actually translate into better power transfer? Is the effective platform available to your foot actually bigger with SPD-SLs over SPDs?
I like SPD SL pedals because I find them easier to clip in and out. I have dual sided SPD/Platform pedals on my mountain bike and I always struggle with clipping in, although once in they work well.
@@eggeggeggegg I think from a power perspective it's the same but the comfort to bring this pressure onto the pedals changes a lot between spd-sl and SPD (but also heavily depending on the sole stiffness of the shoe and the construction of the pedal). If I do heavy pressure onto my SPD shoes/pedals, after some time I can feel that the pedal is not below the whole shoe and my feet bends with the shoe around the pedal. With the SPD-sl I do not have this feeling because the sole of the shoe is stiffer and the area of the pedal is much bigger.
This was a really good quality video, well done. A bunch of your earlier 'sciencey' videos were really not solid enough even for TH-cam, left more questions than they answered. But you explained the science well and performed a legit test/ demonstration. Must have been the lab coat. Well done
On longer distances and rougher tarmac, I found that front suspension +skinny tire is definitely faster than rigid fork +wider tire(@25-35kph). With the suspension I can also hold an aero position for longer, even on bumpy surfaces.
Great point, I run a 23 on the front with a suspension fork with a lockout for climbing and that is really comfortable with little of the jarring that narrow tyres usually give, the suspension fork adds weight but that doesnt bother me
Loving 30's on my Roval C38's!! I don't feel any faster with them, but I also do not feel any slower. The increased comfort on the bike is well worth the wider rubber & slight weight penalty!!
Yes, I agree... I moved up from 23mm to 25mm, not much difference in size but the comfort is greatly better. No loss in Speed vs Power. I am having a new set of wheels built with 32mm can't wait to sport these bad boys. "OORAH"
I just switched my Vittoria Corsa’s for the Conti’s 5k’s primarily cause my LBS was out of the VC’s… the first thing I noticed was the grip and handling of the bike… the VC’s with their wider tire profile were/had way more grip than the narrow Conti’s when going thru turns… and the ride felt smoother than the Conti’s… I just wish the VC’s were as puncture resistant as the Conti’s…
Definitely will change to bigger on my next replacements from 25C to at least 28 if not 32 with latex tubes. I am older and light so the benefit of less bumps through already stressed hands will be a blessing. I can ride at 40km/h but it quickly wears me out!
Very interesting topic, thanks GCN :) I ride 32 mm GP 5000, super happy! One thing I would point out is that 45 psi for 32 mm tires was a bit too low for you, Sy. According to the Silca pressure calculator, the optimal pressure for 32 mm tires, 75-85 total weight, on "worn pavement" is ca 60 psi. 45 psi is for gravel, so on pavement it did slow you down. According to the Rolling resistance webpage 32 mm tires have less rolling resistance than 28 mm at equal pressure, but similar resistance at equall comfort. You mentioned in the video that 32 mm tires felt more comfortable - so the pressure was indeed too low for this comparison. Fair comparison would be at equal pressure or at equal comfort. I'm really interested to see what would happen in these two cases, because in your test the aerodynamics is also considered. Is this an opportunity for Round 2? ;-) My opinion is: 28 mm tires and narrower are optimal for light, fast riders (average > 40 km/h), who don't mind being less comfortable, who don't mind have a bit more punctures and ride on good pavement. Or they just like the look of narrow tires :) Btw, you mentioned 10 watts of difference, but in the video you showed only 0.5 watts - which one is correct?
@@markconnelly1806 You are right, width directly not, but the probability of pinch-flats is actually lower with wider tires (due to higher volume and higher profile), that was what I meant. But I agree that tire casing, design, material are more important.
Great stuff. It's tough for old dogs like me to learn new tricks...My new bike came with 26mm tires, I moved to 28mm (which were an improvement, particularly at lower pressures) and based on what you shared here, it's definitely time to try 32mm next. Someone in the comment string probably already made this comment earlier, but rim width has a big impact on how well a wider tire is going to work with your bike, not to mention having enough frame clearance...which isn't a problem on my new road bike, but is definitely a problem on my 2007 vintage bike (25mm max clearance and skinny rims to boot, unfortunately). I also experimented with running lower pressures on my old bike (80 PSI with 25mm tires) and suffered too many pinch flats as a result. My new wider rim / 28mm set up allows me to run much lower pressure (65 PSI) in spite of me weighing 170lbs, and in general I am experiencing far fewer flat tires, which is possibly the #1 upside out of the whole deal.
This experiment would have been more interesting to have two pressures for each tire wide. The vibration loss is dependent on road roughness. The tire pressure choice in the video may not be optimal for the given road condition. It may be that 32 mm at 60 psi has a lower resistance (power requirement) than 28 mm at 60 psi. Would be an interesting topic for the next video.
I’ve been running wider tyres for a few years now. I’m currently using 35c as I love the comfort and versatility to mix up the surfaces I can venture into. Riding with my mates is harder when there is lots of surging but otherwise I love them. I started off with 32c when the GP5000s came onto the scene and they were great but wore out quickly, the 35c from Pirelli solved that issue. So much more comfort for not that much more noticeable effort 😊
32c is best for current gen roadbikes. The manufacturer's ulterior motive when forcing the trend to shift to wide tires was to make modern bicycles safer. Small tires are too dangerous for disc brakes because they lose traction easily. Safer is better than faster. in motogp you can fall many times unscathed, but road cycling use public roads which are much more dangerous.
I rode the same 6km every day for several years, and regardless of mountain bike, road bike, gravel tires, 25c, 33c, the time was always 15 minutes +- a minute with no bike "winning". My position, winds, traffic were vastly more important than the tires.
Interesting real world test, thank you Si and co. I run 22mm Conti Comp tubulars on Campy Bora One 50s and yes, you might laugh but then the roads are beautifully smooth like a babies bum here in the mountains in Andalucía. Whereas, my wife runs 32mm GP5000 S TRs on a lightweight Langma as she doesn’t ride crazy fast but loves the grippiness, cornering confidence, stability and comfort they give. It shows that the road quality and nature of the rider are important factors in tyre choice.
Been using 28 for about 2half years and im pretty satisfied with the experience, im using a 1988 raleigh racer bike and 28mm tires work great at long rides.
@@discbrakefan I don’t know man, I experimented a lot.. riding SLR 1 wheels from Giant, 24mm inner I think.. 32 min tyres.. going below 60 psi feels too plushy and bouncy.. My system weight is around 94kg total… I tried with 50 psi and just sitting on the bike, the rear tyre looks too flat..
My new Trek came with 32c tubeless tires, and it's made me so much happier riding. The increased comfort and the feel of increased stability makes a night and day difference. I don't feel any slower at all compared to my old 25c tube tires on my older bike. Couldn't recommend wider tires more to anyone who will listen.
I just switched from 25mm to a 28 mm front and 32mm rear, never going back to narrower tires, the comfort and stability far outweigh whatever the speed difference is.
I started running big chunky boy 35 mm Continental GP urbans on my 25mm internal rim width wheel set and I love it! So comfortable, and I keep setting PR's on my strava. I'm a fan and convert of bigger, wider tires. All about that comfort
Just be aware of the very narrow tread the GP Urbans have. On those wide rims the sidewalls balloon out way past the tread area, and the sidewalls are very weak.apart from that its a lovely comfy relatively puncture resistent fast tire for a modern endurance road bike.
GCN Science in eastern Iowa…recently did B2B 39 mile (62.7 km) pavement route (2.5 miles gravel) with 1800 ft elevation (its Iowa, so rolling hills…max 1 minute climbs). Weather was similar with a bit more exposure to light headwind on the 2nd day. 1st Day on Specialized Crux (2018) with 32mm (34 measured on 22.5i) GP5K TL’s at 45F/50R psi. 2nd day on Specialized Diverge with 44mm (44 measured on 25i) RH Snoqualmie’s at 37F/42R psi (usually 32/37 for gravel). Both set up tubeless. Both bikes have the same model Quarq PM. I’m 190 lbs/86kg. Both bikes run SRAM AXS 46/33 front, 10-28 Crux, 10-33 Diverge. Rode by PE (totally nonSCIENTIFIC). Results, Crux 2:17:17. Diverge 2:16:53. 24 seconds total separated the two rides. Approximately 17 mph/27 kph average speed (on the back end of Covid so wasn’t going for gold) Metrics: average cadence 84 on both rides. Ave HR 141 on Crux/32’s, 146 on Diverge/44. NP 172 on Crux, 187 on Diverge. Effort “felt” similar between both rides. What do these numbers mean…probably not a whole lot, but fun doing these completely non-scientific comparisons. BTW, 32mm FTW on pavement rides. Don’t think I’ll ever go narrower ever again.
I started with 23 and now running a 32. I would say 23 is of course faster but I love the comfort and versatility that 32 provides. I don't think I would fo higher than 32 though (would just switch bike to my MTB)
Hi! I still use 28 tubeless, but with new wide rims. Anyway, I think that if you make a test with a peloton the numbers will turn in favor of the 32. The extra drag will be mitigated and the benefits in comfort will pay of in long stages. Thinner tires (in this new standards) will probably continue to show up in TT Stages, at least on the front wheels.
I'm riding 28 mm tyres for almost 6 years now (Hutchinson sector 28) and I'm not slower than with the 'standard' 23 mm tyres I used before. What I like is the comfort the 28's bring. Since I ride a gravel bike which is fitted with a 650b wheelset with 47 mm Vittoria Terreno Zero's I almost didn't use my pure road wheelset anymore. I'm not measurable slower with the much wider tyres and the amount of grip with even more comfort let me take these wheels as my first choice for almost all of my rides. The wider tyres feel just a little bit slower in accelerating and that's why when I'm riding in a group makes me choose the narrower 28's, all my other rides are with the widest tyres my bike can fit.
The fastest tyre at 40kmph will likely be the one that matches the aero profile of your wheel. So you need to do this experiment again with wider wheel rims for the 32mm tyres.
I went from 23mm & 25mm to 28mm tyres on my road bike and I’ve never looked back. The improvement in comfort is sublime and I’ve gained a bit of speed too as I’m far more comfortable than I was on the thinner tyres 👍🏾
Are you using rim brakes or disk brakes? I'm wondering if 30mm tyres (looking at the schwalbe G one speed) would fit the Shimano 105 R7000 rim brake caliper. I know the spec sheet says it is compatible up to 28mm.
I run 25mm on my bike. I tried 28mm as there was plenty of room between the width of the forks but the tyres were too close to the underside of the fork crown. The smallest piece of gravel would jam in the gap and have me sailing over the 'bars!
I was riding 28mm and switched to 25mm. I found no big change in comfort, but it’s much easier to slip the tire in through my rim brakes and the smaller spare tube takes up less space in my saddle bag.
In my experience if out and out speed is what you value most a 25mm tyre is better as it makes for a lighter more responsive wheelset. If you value comfort and grip more then the 32mm tyres are better and only sacrifice about 1-1.5mph average speed.
I assume you’re saying the 1 -1.5 mph average speed sacrifice going from 25 to 32 is your experience when calculating type of road hills and wind as opposed to just a flat road the above test was made with? What is been your experience with the difference in speeds uphill 25 mm to 32 mm?
You'll find even bigger gains if you compared 25s. Way more aerodynamic than 32s. The move to wider rims and tyres is mostly fashion and to compensate for harsh frame design. I agree they are perhaps a good idea on UK roads. Another point is that tubeless is great for MTBs with high volume and low pressure, but on road, even with 32s it doesn't work well at all. The tyre goes down too quickly for the hole to seal, makes a mess and is a faff compared to just putting in a new tube.
Glad to see that Vittoria and the cycling world in general is catching up, riding on the coattails of René Herse's Jan Heine's pioneering research! Wide tires aren't necessarily slower. Real world results keep confirming this. Great video gcn. How about getting Jan on for an interview?
I'm impressed how strong you both rode despite the illness leading up to the event. Eating and resting conquers races! Syd is riding so much stronger compared to 1 year ago.
![ประสบการณ์ จ้าง Developer ที่ผมจะไม่มีวันลืม [ภาค2]](http://i.ytimg.com/vi/pZbsSDRrmXA/mqdefault.jpg)
What size tyres do you use?
57mil
I use 32mm for more comfort and for long term better health of your back.
32mm for me on my latest stead 👌
Size 30 Marin Nicosia
28mm gp5000
My Trek came with 32mm from the factory. I was also biased, that I "need" narrower tires. I have ridden the 32 Mill for ~2000km, switched to 28 mm for 6000km now and decided to go back to 32mm. I haven't seen any improvement in speed or anything like that with the 28mm but the comfort of the 32mm is so much superior that I prefer that. My usual rides are somewhere between 80-100km with 28-30 kph avg. And yes I am way too heavy to consider myself a "real road bike rider" :D
You sound like a "real" road bike rider to us - that's a lot of km! Cool to hear you're going back to the 32mm 👍
80-100km regularly sounds like a "real" road cyclist to me!
@@Goriaas especially at that speed!
I don't think there is different for that speed :D
My Domane came with 32mm but somehow the tyres were to wide for my liking. I dunno why but this really affected my motivation to ride. So I upgraded to Carbon wheels to compensate for the racey feeling. Definitely didn’t regret it.
My allround bike came with 32mm tubeless and I fell in love with them. The differences with my previous 25mm clinchers is massive:
- way more comfortable to ride on
- Can be easily inflated by a small hand pump because of the lower pressure needed.
- Can handle light gravel comfortably meaning you can add extra gravel tracks to your route.
- Can also handle rougher gravel without risking a flat, but it wont be very comfortable.
- feels more stable when turning
All in all I'm very happy with it. So far I've ridden more than 3k km with it without any flat.
what bike do you have?
I totally agree, I had the same experience , coming from 23mm to 32mm on the front wheel and 28 on the back .
@@vgud It's the Giant Contend AR 1
Suspect you’ll be putting just as much air into the larger tire
Well you are in love because your bike is not comfortable. Get steel or titanium bike and you will feel the same love with 23 or 25 mm
My endurace came with a 30 up front and a 32 in the rear. It’s 95% used for tarmac but the roads aren’t the best and I’ll soon be running 35mm front and rear. For me the comfort and confidence a few mm’s bring are the difference. Im also aware that I’m never winning the tour or going pro so I don’t need to lie to myself and run 25’s just to suffer.
Great to have a bike that can fit chunky boy tyres!
Absolutely agree with you.
I believe that after 32mm, the law of diminishing returns kicks in on a road tire width. I mostly ride a gravel bike set up for road: Enve 3.4s rims with Rene Herse 35mm slicks. At 195 lbs, I run 110 psi - hard. Very comfy ride, but slower than my road bike. Much slower. My road bike has Mavic Rys rims with 28mm Conti 5000s. I run them at 120 psi. It's a different world. Huge acceleration advantage for the road bike. Climbing is vastly superior on the road bike. And I have no doubt that it's the different tire width, not the different geometry, that accounts for MOST of the difference in speed. I'm going to buy some 32s and put them on my gravel bike. My bet is that the performance difference will narrow vastly between the two machines. Any takers?
@@MrIsaac-dh3uh let us know of the results! i also have a gravel bike with 42mm tires, and contemplating buying a road bike.. but if putting 32 mm tires on gravel bike is a good enough improvement - I'd rather go with that
@@MrIsaac-dh3uh a lot of roads I ride gravel on are way too chunky for 32mm to be comfortable. If it’s nice pebble sized stuff, might be ok
For the past 3 years I was riding 25, and last week I changed to a 30mm. I am so happy I watched your video, it’s much more comfortable, not affecting the speed, acceleration is amazing. Just more fun. Thanks Simon and GCN
Are you using rim brakes or disk brakes? I'm wondering if 30mm tyres (looking at the schwalbe G one speed) would fit the Shimano 105 R7000 rim brake caliper. Is there anyone who tried it out yet? I know the spec sheet says it is compatible up to 28mm, but they do not make certain tyres in 28mm.
I was happy with 28mm until I accidentally ordered 32mm tyres by mistake, best mistake I've ever made for biking. The performance is the same for me but the comfort is so much more on long and quiet back country roads. I'm converted.
There's always a compromise.
A high speed bike is also terrible at slow speeds.
Awesome Colin!!
Next step is to pick something with 4 inch tires and never worry about the road You take :D
@dreyn7788 that's only with frame geometry, not tire size. At least not with the sizes we're speaking of.
@@unclebobqq😂
Back in the 1990s, I was running 23 mm and 25 mm tires on my road bikes, and my racer friends were telling me I should be running 18 mm tires. Now, I'm still running 23 mm and 25 mm tires on my road bikes, and I'm being told I should be running 28 mm or 32 mm tires. Of course, back then I was being told I should have triple chain rings on my road bikes. Now, I'm being told a single chain ring is just fine.
Marketing never sleeps, and doesn't have to innovate if you can just recycle :)
Well when the kassette was 6/7/8 speed a triple chain ring gives enormous advantages. When however you already have a kassette that has 10 gears or even 11/12, the advantage isnt as big. A 1x setup in the 80s with 6 gears has half the gears as a 1x now with 12 gears. So while im not on the 1x train, rather the 2x, it makes sense for many areas.
@@kaseycarpenter73 i had an mtb now i have shifted on a hybrid bike which has 28 c tyres, on roads it is fantastic, i feared that on rough roads it would have less grip and uncomfortable, today i rode it on a hilly unpaved track, i never felt that the tyres have less grip or uncomfortable
@@gulmuhammad5158 Nice. I have an allraod that can take up to 50c tires. So when I want plushy plush, I put on my 650bx50s and steamroll over everything -I mean literal potholes, lol. When I have the zoomies, I swap those out fo the 28mm deep dish rims, which, with inserts, I can run at about 70psi and still manage some level of comfort.
@@prokopf-9332 The number of gears in the cassette has changed, but the gear range for road bikes has remained about the same. You could get 11-34T in a Shimano 8-speed cassette, and you now typically get the same in a Shimano 12-speed cassette for road bikes.
I'm currently riding 28 mm which is the thinnest I've ever ridden. Before that I was riding a hybrid bike with 35 mm. I was expecting the 28 mm to be a really rough ride, but actually have no problem with it at all. Find them perfectly comfortable. That's probably because even when I was riding the 35 mm, I was doing so almost exclusively on the road, so they were always held at relatively high pressure, and so I'm already used to that feel.
I just changed my 28mm to 32mm and found no difference in speed but, ride comfort was absolutely superb! I accidentally climbed a 16% to 18% and took the climb much better than expected. Hills were no bother, speed consistent and being a 110kg belly buster I thoroughly enjoyed the ride. Sticking to my 32mm tyres - Schwalbe Pro One TLE Addix-Race Evolution, awesome! At 62, I gets me thrills where’s I can! 🤪
Just bought my first road bike, how would I know if I'm able to fit 32mm? It currently has 25c, not a lot of clearance with the rim breaks but can that be adjusted?
@@_LC__for your first bike and you know little about bikes? Go to the local bike shop and ask them 😊
Air resistance is proportional to the square of velocity. Hence, required _power_ to maintain a velocity is proportional to (velocity ^ 3). Reason, you overcome the air resistance in shorter time, hence the square of velocity, times the velocity..... Consequently, the speed difference between 28mm and 32mm driven with the same power, is only one percent, 0.4 KM/h. Assuming of course the 10 watt difference as mentioned in the video. The small speed difference is relevant for competion, but for recreation? For me, comfort is more important. I moved from 23mm to 25mm back in 2008, moved to 28mm in 2010.
45psi! Wow, I remember people routinely pumping up to 120psi with 23mm tyres a few years ago. I never thought there was much point in that as it was just uncomfortable and skittish, and I felt so vindicated when Schwalbe did some research in perhaps 2010 and concluded that lower pressures (up to a point) were more efficient because they allowed the the carcass to absorb micro-bumps without vibrating the whole bike (which of course takes energy) - the point that everyone seems suddenly so aware of.
I must've missed the PSI being used but found it in the video after reading this comment. Wow 60 PSI on a 28mm? I'm still doing around 80 on mine.
Ive overinflated tires on a car but that has suspension. Low tire pressure is key without suspension
I use about 85 psi on my 28c. I'm not confident in avoiding a pinch flat going lower. I'd love to try 32c but 28c is the most that will fit under my 105 brake calipers
@@0xsergy Look at the tyre pressures of sherp ATV, they have no suspension and just use the tyres softness.
I was running 18mm (and U-shaped!) at 120 psi 30 years ago as the best expert's recommendation
My Scott Addict comes with 32 mm Schwalbe One tube tyre and I run 53/58 psi F/R. Far more comfortable than my older bike's 28 mm at 70/80 psi with no significant loss of speed.
my dads bike has 32's and i borrowed it to climb in the mountains, i didnt notice them being slow at all, in fact on the descent i cornered like i was on a motorcycle, now i want 32's
Very interesting video. I ride long distance, sometimes into ultra-endurance (circa 200km) and I opted for a 32mm. Reason being that I wasn't trying to go as fast as possible, I wanted to go as far as possible and the argument was that comfort over an 18 hour ride would be better than an extra 1 or 2 kph over the same distance. The beauty about this of course, everyone can choose what works for them!
Ultra is above 300km?
I'd say ultra doesn't start until you are doing more than 600km... Why, loads of 600km Audax rides.
Mark Beaumont in all his endurance related videos, podcasts and books claim anything over 100 miles is ultra. I'd say he's fairly well qualified to pass judgement. I am not tied to a single definition, in fact, if someone said 200km was bang average I couldn't care less. It's about getting out, turning the pedals and smiling. So if I ride 200km +, whatever the definitions are, I ride a wider tyre for comfort. That was simply my point.
@@Kobe404 well, I stand corrected. I'll not disagree with Mr B. I'm a fan of 35mm tyres for long (over 200km) stuff, and night riding. For quicker paced stuff of 200km I usually use 28mm tyres.
@@hectorkidds9840 the beauty of it is, we can all go with what we think works best. I just did a long ride of around 250km for charity and went back and forth on tyre size for ages. Eventually settled on the 32s because I'm lazy and couldn't be bothered switching to the 28s 🤣🤣🤣
A few months ago I changed from a 25 mm to a 28 mm Continental Grand Prix clincher tire mounted on a Vision Team 35 wheel. Beter cornering, less pressures, a bit more comfort, better on those small gravel roads when 'necessary', and much better looks. Love it. Go for that wider tire when possible is what I think.
I went to 23 mm, so much fun
@@stibra101 from?
@@konstantin7596 25
hi have you tried the tires at same pressure? which is faster? im buying soon thx
@@hugobrown2516 I use about 5.8 to 6 bar. Love the feeling. Had one puncture in 735km with an offroad rock.
I replaced my aluminum wheels with carbon wheels and went with the recommended tire size which were thin. It vastly improved my ride, but I recently purchased a look with thicker tires and was astounded at how much more comfortable the ride was. Given that I am a casual rider, I prefer the comfort.
28mm are statistically supposed to be fastest. 32 is more comfort for no real loss
I recently put on Vittoria Corsa 30s and I'm running them tubeless. I love the comfort of the ride and the grip is incredible. Totally worth it.
Are you using rim brakes or disk brakes? I'm wondering if 30mm tyres (looking at the schwalbe G one speed) would fit the Shimano 105 R7000 rim brake caliper. I know the spec sheet says it is compatible up to 28mm.
I'm running disc brakes on a Tarmac SL6 with Shimano Ultegra. Try to go as big as possible, you'll be happy with the comfort.@@MultiLuc28
28-32mm tubeless are a nice sweet zone for me on UK roads, fast, comfortable and low rolling resistance (P zero race tlrs or 5000s tr) on hookless rims.
Bumpy UK roads do feel better with an extra bit of width!
I ride 28mm@front (more aero) | 32mm@back (more comfort). Remember to take a look at your weight distribution on the bike to give each tire an individual calculated tire pressure.
Would be great see a video about weight distribution / tire pressure and a mixed / individual tire setup for the front and back wheel.
This makes a lot of sense. We see this in motorsport all the time. I wonder if it will become common practice.
I've got the same 28 front 32 back just because that's all the bike shop had day before a long bike trip .what pressures do you like to run I'm 81kg run 80psi but looking at this vid make.me think I'm running too high and was also think bout swapping back to 28 but the 32 is comfy
@@chrisswan3986 That depends on the inner rim width and whether you have a clincher, tubular or tubeless setup. At a system weight of 90 kg and for a tubless setup with an inner rim width of 22 mm i would recomand 65 psi at the front (28mm) and 59,5 psi at the back wheel (32mm) for a dry road surface.
@Gravel Devil thanks yeah 22m width tubeless setup Hutchinson fusion5 .thanks for info
bigger tire on the back is great, although once you get to bigger sizes it does effectively change your gearing somewhat.
This came at the perfect time. I have a Trek Checkpoint that still has the stock 40mm gravel tires that need to be replaced, and since I ride it exclusively on the road now I was looking at going with a 28mm or 32mm road tire. I currently ride between 15-16mph over 20-30 mile rides so I think the 32mm will suit me better at this point.
Go for the 32C tires. I also have a Trek Checkpoint SL6
which I use mainly as a road bike. I ride at about the same speed averaging 40 to 60-mile rides. We have significant hill climbs all around where I live. Switched to Hunt 35 X-wide hookless wheelset with 25mm internal width and Continental GP 5000 S TR tires. Very noticeable difference. You will be much happier with the 32c tires.
I’ve got a Checkpoint and have two wheelsets, one with 32mm Maxxis Refuse and they are great for everything. The original Specialized Diverge (2016 ish) gravel bike came with 32mm tyres as standard.
@@AndyPaul-wr5hm Hi Paul, isn't 25mm too much for a 32mm tire? Could you measure how wide is the tire on your wheel? Thx I have GP5k 32mm on 21 inner wide wheel and is 30.5mm wide when measured.
@@petertapaj4859 There is a table on the Continental 5000 S TR website that shows the max rim width supported by the 32C tires is 25. I don't have calipers to measure the tire width on the wheels but I can say that I have ridden over 275 miles and 21k vertical ft with this setup with no issues.
32f, maybe 35r if you have racks? Id say keep it wide enough to absorb road bumps. Im on 28s and theyre okay, just a bit rough offroad.
I moved from 28 to 32 but kept the same tyre pressure in the 32 that I was running in the 28. The research that I carried out suggested lowering the pressures in a wider tyre if you want better comfort, or keep a higher pressure in the wider tyre for lower rolling resistance/faster speed.
1:49 I'm loving the Sophisticated Si 🤓. You get this sense, he was very proud of himself for using the word "hypotheses".
I predominantly ride audax and touring. Love my 32mm slicks for combination of comfort and speed but currently run 35mm slicks because I prefer a bit more rubber under me when the bike is loaded. They are perfectly fine for the average speeds I ride at (21-26kmph) and can handle all British road surfaces plus bridlepath gravel.
We ride a tandem and it turned out that our otherwise perfect 50mm slicks (Schwalbe Kojaks) were weakly protected against punctures. A protection belt inside a tire is a nice thing but these extra millimeters of the tread are just necessary to do the job.
@@PrzemyslawSliwinski that’s a pain. I run Panaracer Gravelkings and found the tan walls look lovely but puncture too easily. The all black however seem to be pretty bombproof.
@@Quevallyn I have had this same experience lol. Black tires never have an issue...any of the color ones or tan wall gk slicks, I puncture a lot
My Merida Reacto 6000 came with 25mm tyres, upgraded to 28mm tubeless tyres on carbon rims 3weeks after and absolutely love it!
I did ride on 23s for years then moved to 25s. Then tried 28s for three years. I found 28s to be noisy, cumbersome, dead feeling. Moved back to 25s and the ride just feels different - better, more enjoyable. BTW so glad y'all keep reminding us to just be out there. Good job as always.
Per chance, are you a featherweight rider like me?
Lol no, 69" 200lbs and 35 years past my prime....
I tried one winter on 28mm tyres (2004). They were more comfortable, but like you I found them to be sluggish and dead feeling. Needed to change down a further gear also to get up the hills. Ridden 23 and 25mm ever since and am happy.
I agree with you. I find the wider tires feel slower. I rode 23 for years then moved up to 28 and back down to 25's. Used the same tire brand. I am not sure if the wider tires were actually slower but the bike handled sharper and felt more responsive and faster. Also I felt that there was better road or surface feel with narrower tires.
im 60kg..and 23mm at 100psi is always the fastest and the funnest....vibrates like hell but im under 20km rides
Interesting video, thanks! Currently using my gravel bike as a do-it-all bike with two wheel sets. On the road wheels I run a 32mm Conti GP5000 tubeless, works brilliantly, super comfortable and extremely forgiving when riding gravelly cycling paths. Not concerned about speed too much, came to accept I am very slow ;-)
I specifically remember during the 2022 Tour de France that many teams were using 26mm tires (except for the cobblestones of Paris-Roubaix). 25mm are perfect for me. My brother rides 28mm, and we always have identical data after 40-50 mile rides.
Vingegaard has been using 24 mm in 2023, Pogacar as much as 32 mm. Average TFD is 25-26 mm might be. I presume they use different tyres depending on the stage, bike choice, etc.
At 10:32 Si says, "28s at 40k/h were statistically better....10W more efficient". The table at 10:16 regarding average power required on 28s at 40k/h was 343.0W and at 10:21 the table shows the average power required on 32s at 40k/h was 343.5W. I only see a 0.5W power difference. Can Si show his math? Or was this a typo on the tables?
Yeah either the charts or the dialog is off
I was confused about that too, hey GCN can you clarify?
@global cycling network
GCN "science" at its best. 😂
He's blown it
Spot on. Totally reflects my experience. I use 28mm in front, 32mm in back, with wide rims
Yep...I did it on my 2022 s-works tarmac sl7 and now on my 2023 trek madone slr...28mm in the front and 30 to 32mm in the rear...speed & comfort all day
Beginning at the 10:17 mark, Si claims that the 28mm tires are 10 watts in savings at 40 km/h over the 32s but the data illustrated says the 28s were 343.0w at 40 km/h while the 32s were 343.5w. That's only a half watt, not the 10 watts claimed as being the advantage at the higher speed. CGN, am I missing something here?
Exactly. What's up with that GCN?
@@nctrns You won't get a reply because the whole premise of the video doesn't take into account the complete inconsistencies of the road. This evaluation needs to be done with the wheel on a weighted rig on a rolling road dynamometer.
Good spot Jesse. Sorry, that was a typo. The 28mm were 331W at 40km/h so slightly over 10W less!
@@fredbrackely You have missed the point of the video. A rolling road, even with the tarmac simulation surfaced roller, does not replicate the inconsistencies of road surfaces and how different-sized tyres and pressures deal with traction loss reduction as tyres widen.
I remember fitting 26" x 4.00 to my bike, and all I can say is that the difference was incredible, it completely smooths out bumps in road, and gave me a little bit more confidence on the occasional gravel track.
Sounds comfy!!! 🙌
Expect to see more of those fat tire E-bikes.
I used to switch from my 28mm road tyres to my 32 CX tyres when roads got slippery in Autumn each year. Then several years I realised I didn't go any slower. Not used the narrower road tyres since. Plus as I tend to go off road a lot even with the 28mms, I was even faster with the fatter, grippier and more comfy tyres there too. Less rim smacking too.
I switched to lower pressure even earlier after doing bike comparisons and discovering the lower pressure tyres and as a result way comfier bikes were faster.
Wider tyres also need wider rims to prevent a lightbulb shape which is not good for aero benefits. The difference in this test could be simply down to that rim width aspect.
Very informative. I am definitely not a racer but I do like to go as fast as I can. However, comfort is the main factor for me & there were 2 stand out comments. At 04:10 Simon emphasised the importance of vibration loss - a real world issue. Then at 10:30 he said that the 32mm tyres were "way more comfortable". These are the key issues for me
I upgraded my endurance bike's 32mm stock tires for Pirelli's 28mm Cinturato tires (for a mix of better performance and puncture resistance). Something that is not mentioned in this video is that stock tires are often not the best and that switching for higher grade tires (32 or 28) could make a huge difference in ride quality. I saw a noticeable difference in cornering, handling and Strava PRs. Long story short, the tire quality can make a big difference.
A good point to make. I just upgraded from Bontrager 1 to Bontrager 3
Went from 32 mm to 28 mm. I only have one 33 mile with the new tires. Time will tell.
@@2006zo6vette how they are ? 😮 I am gona give the 28mm tyre a run since i always run 25mm tyre hope it will help my cornering handling and confort without affecting the speed !
I like the new trend in modern road bikes, coming with room for 34-35mm tires. Makes the bike much more versatile, and most people don’t have perfectly smooth roads to ride regularly.
If you ride on the road, most roads are smooth enough assuming the road is not a neglected road.
I've been running 32mm Hutchinson Sectors for a few years now. I'm a 58 yo tall clydesdale. I tried these as winter tires initially, but liked them so much I never went back to 25s or 28s. I think I'll try the Vittorias at 34c when I next buy tires. My bike has clearance for 35s.
I mention this video to fellow riders in my bike club, as the whole philosophy around tires and tire pressure has come a long way! I remember 15 years ago being taught to fill my 25mm's to the maximum air pressure! As my main bike, I now have a T Lab R3 Omni, and ride it for both road and medium gravel rides. Using 35 mm PanaRacer tubeless 'slicks', I have no problems keeping up with my group. I'm in the 24 - 26 km/hr classification, about 80 km 2 - 3 times a week with road, or mix with about 60 km gravel rides. Much smoother ride, do need a lot more cleaning with the gravel rides, and much fewer flats (but I have put an innertube in on a flat recently!). I know others doing the same thing. Was thinking about going to 2 wheel sets (28 mm and 35 mm), but this works fine for me.
running 35mm Rene Herse tyres for 2 years now on my Canyon Endurance and I love it :)
only problem I found is that is getting a replacement innertube ad a event.... because I was riding 1 month outside on my racing bike this spring and was bikepacking for 3 months after that on gravel:) I didn't get tubless setup this year..... but I rode the Amstel Gold event race and got 1 puncture so ad the first stop I got an extra innertube..... they had only innertubes for 23mm..... and you guesed it I got another puncture..... the 23mm innertube.... barly fitted and got blow out in 10km..... my mates all ride 25/28mm and well those dont hold out in 35mm to good eather.....
had to bail out of the event 15km bevore the end
still running these tyres because I love the smoothness of them so much but running tubless again. and run with 2 spare lightwight innertubes in my pocket now, because my mates still haven't seen the light :D
I love the 35mm Rene Herse Tires! I used to use 32mm Conti GP 5000s, but I loved the speed and feel of the Rene Herse 35mm, I switched. Supple, smooth, fast - plus I can ride anywhere with them.
I bought my only road bike in 1994, it came with 25mm wide tyres. That was so uncool after one season I've built myself new wheels with 19mm Vittorias. How times change.
Yup. Ten years ago my setup was considered as lame :) (23mm + 11-25 cassette)
19mm? Wow I think I never even saw so narrow tyres.
Yup, when I was a kid, I marveled at my uncle's Cinelli with skinny 19mm tires! Way cooler than the thicker ugly ones on my cheap Schwinn!
I tried racing just once in a criterium with 19's, it was awful, never did it again.
@@TimFerber Back when I started racing in 1970, as a 14 year old in the intermediate class, some of the silk (and cotton) casing/latex tubed, high end tubulars were even 17mm wide, and a few of the top track tires were even narrower than that!
We used to pump them up to 145+ PSI, and they rang with a sharp ping when you flicked them with your ring finger. LOL
The sole exception was the Clement del Mundo 'training tires', which were an unheard of at that time (for a road tire vs. cyclocross tires) 26mm wide.
They still had a fine silk casing and latex tube, and were quite responsive despite their perceived excessive width for that era.
As someone with disc issues in my lower back, I switched over to 32mm for the added shock absorption since it means I can ride comfortably for a much longer distance, and I don't deal with pain the next day. I was going to go for some super swish carbon seat post to help smooth out the road rattle, but these did the trick at a fraction of the price!
Why did you break your back? How can I avoid it?
@@fVNzO Completely unrelated to cycling, so no worries! Far too many years of a physical job that took a serious toll on my spine, eventually causing multiple discs to degenerate and collapse. Cycling has provided me with an excellent source of exercise that has made a huge difference in my quality of life. I have less daily back pain now then before I started cycling!
My new Trek Domane came with 32mm tubeless tires. My previous Domane had 25 mm tires with tubes. I ran the 25mm tires at 100PSI rear and 95 PSI front. I run my new 32mm tires at 60PSI front and 70 PSI rear. I have to say that my new bike with the wider tires is much more comfortable to ride even considering that the new bike has some "suspension" built into the frame. The new bike is also considerably faster than the old bike. The new bike with the wider tires is also much more stable at speed.
Interesting report. I'd think that i would never go any bigger than my 23mm, but then again 90% of our roads in my area are pretty silky smooth. Bring on the speed!
After decades of riding 700x23c tires at over 100 psi, I figured the wide rim and wide tire setup (700x32c) on my 2020 Trek Domane SL7 was a marketing gimmick. However, I'm now a believer in the wide rim / wide tire package and can't imagine going back to narrow tires for endurance and training rides. I feel so much less fatigued at the end of a ride and I've been able to ride over the nastiest of roads and gravel w/o flatting (partially due to a tubeless setup as well.)
I have had this discussion with my cycling friends while group riding on multiple occasions. I use 28mm tires on my road bikes which I inflate to 80psi (I'm 84 kg). This combination works great for all "real world" riding conditions. When we do hit the occasional new and super smooth tarmac, then I think narrower/harder tires are great, but even in those rare conditions I don't feel that my wider, softer tires are much of a disadvantage. Of course, there's no comparison in comfort. The wider softer tires make for a much more comfortable ride in most conditions, which if I'm honest, has become much more important to me as I've gotten older. Great video and I love your real world testing!
I run my 28s at 80 psi also. I tried them at 65 and 70 psi at my tech’s recommendation, but get much better performance with enough comfort at 80 psi. I’m 75 kg
@@ancientfifer I'm 87 Kg and also uses 80psi on 28mm Zaffiro Pro Vittoria tires. I'm not riding tubeless.
I've tried 55, 65, 75, 80, 85, 90 and 110 psi already - After 85 PSI the bike receives all the vibrations from the tarmac (and holes + imperfections) I'm used to ride - it becomes a shaky ride with tingling hands. With lower pressures than 70 psi, it seems that the bike get stuck into the ground. The observations were based on my personal experience and feeling, so means almost nothing in science terms.
@@regisateparece yes, I have experienced that "stuck to the ground" feeling at 65 and 70, although its comfortable ride. I'll run at that pressure on a casual recovery ride though, with no big climbs. Happy riding!
That's not very logical.
Tyres are getting wider cause they were crashing with skinny tyres.
The tyres had no cornering ability.
@@Gma7788 That’s a misconception. The tires has a U profile like in superbikes. The area that touch the tarmac is really narrow compared as the total width. So entering in the corner, you’re able to bank left or right and turn as motorcycles, without turning the front wheels. That’s the only way to turn when you’re speeding (in bikes or motorbikes). That’s why the wider tires doesn’t bring rolling resistance proportionally to the width - they’re U Shaped.
Am running 28 on my tcr, very pleased with their performance and comfort.. in this test, the differences in the psi are much greater then their measured speed differences. I wonder about how the actual tire deformation from making contact with the road surface affected the results. Wish they’d done a 3rd run with 32 at higher pressure : maybe mid point ?
Loved the conclusion at 9:40 that it doesn't matter what width tyres you have the most important thing is you're out riding in the first place! Awesome! (btw I have 32 tyres but I'm motivated to experiment with softer pressure!)
Did my triathlons and an Ironman on my new Michelin Power Cups 28 mm, tubeless this year. Very impressive, fast, sticky and puncture proof tyres. Didn’t notice me becoming any slower, though wayyyy more comfortable ride. Pressure is at 72/74 psi but I am a heavier rider.
When I first rode a road bike 20 years ago, I put on 21 for one year and then progressed for 23 about 15 years. For the last 3 years It is 25. It is still on rim brake alu wheel about 1.7 kg. I have no choice as more and more online tyres come with 25 minimum and it's fine by me as I don't notice much difference between 23 or 25 as I am a senior citizen rider, travelling at 25-30 km/hour.
I tried 25 instead of 23 and defiantly noticed the différance, the 25 rubbed inside the mudguards, defiantly not changing 4 perfectly useable vintage steel for modern plastic landfill crap.
l ride two road bikes one with 32s @80psi one with 25s @100psi . l can go lil faster on the 25s but l prefer the 32s more BTW the difference is only 3km/hr on the same stretch sprinting :)
I’ve been riding with 32mm tires for few years. I love it. The 32mm tires absorb road vibrations well.
I've been riding on 35 mm Schwalbe Maranthons for over a month and I am really enjoying the increased comfort and stability, and I'm not really seeing a drop-off in performance. One thing the increased stability gives me is confidence. I feel safer standing on my pedals when I want to really put down the power, and also faster speeds feel much safer, so I'm less inclined to feather those brakes, even on relatively rough roads. Yes, technically my 28 mm Continental Gatorskins are faster, but the difference is so slight I don't really miss it.
Mind you, the speeds I'm referring to range from 22-33 mph, so there may be some +33 mph performance I am just not aware of.
Gatorskins are notoriously slow, I mean they're great and (mostly) never puncture but they ain't fast.
Exactly, try gp5000s and they'll feel quite different.
Started on 23s, moved to 28s, will be 30s next. My secondhand topstone came with 42s, very comfy, great around corners.
The chart shows 343.5 watts for 32 & 343.0 for 28. How is that 10 watts better? Isn't it only one half?
I'm pulling of the 32s if they're costing me ten!
40k speed had the 10 watt difference.
Wow, now this was some seriously valuable science! Thanks lads for doing this (and for making it utterly entertaining as usual). I think I'll stick with 28, but the promise of better comfort with 32 is enticing
Cheers Joe, glad you found this one useful!
Maybe my next set Ill split the difference and go 30mm haha. Currently on 28mm and definitely perfer over last 25mm set.
Crazy how my used bike came with 23mm, 25mm became the new standard three years ago and now we make a case for going wider than 28mm.
25c was the standard a lot longer than three years ago.
It's changing so quickly now!
@@cup_and_cone yup, and most rim brakes are difficult to set up with 28mm or wider tyres.
@@geisslersonMC A lot of people seem to forget wide rims & tyres are a big advantage of disc brakes
@@discbrakefan up until 28mm, there has never been a problem with rim brakes, the only problem was some frame manufacturers leaving too little space between e.g. the rear forks or seat tube and the tire.
Thank you for performing a scientifically sound experiment and showing/testing two important points:
1) That gathering a statically significant sample size can be boring but necessary. Wouldn't be surprised if Alex really was that bored by the end.
2) Testing at a speed the average person rides at. Too often companies make claims at 40 km/hr.
The only bit that was amiss is Alex wearing shirts with a lab coat.
A very intuitive video that raised a huge number of very informative comments. I ride 80-100+km on rather imperfect tarmac with 25mil clincher on both wheels which are way more comfortable than the previous 23s, but seriously tempted to go to 28mil on the back wheel as a start. Thank you all :)
28/30/32mm tubeless.. you wont regret it, just double the sealant amount
Great, informative video. However, the results might be slightly skewed by your suboptimal tire pressures. The Silca Tire Pressure Calculator says you should be more like 61 PSI for the 32mm tires and 76 PSI for the 28mm tires.
45 psi in the wider tire, i agree with you. I end watching the video after 2 min and 50 seconds lol :) why do people always do unserious test of these things. Only to get a lot of comments. And why not try the same psi in both tires?
@@allemyr Because GCN isnt really tesing channel, its more of a fun based channel and commercial based channel. Most of these tests feel really rushed or biased which is sad, beacuse it takes away also lot of its entertainment. Plus most of these "tests" are sponsored so you cant really show that theyre new extremely overpriced product is actually as good as the old one.
@@alexmichl3137 Yes I agree with you its entertainment. And I also agree with you that the dumb choice to setup these tests takes away a big part of the entertainment. When I start to watch tests like this I always get some sort of headache early. Hope all people get that for viewing stuff like this :)
The topic is super interesting about tire pressure and tire sizes. The test methology is so dumb so I won't comment the test in this video.
Best!
/ Karl
@@alexmichl3137 Because running wide tires at high pressure negatates the benefits and creates serious vibration as well as packing on weight.
@@danielhall3895 Sorry but running 45 psi on 32 mm tire is just extremely underpressured, thats recommended pressure for chunky mountain bike tires. Plus it doesnt add weight, as air weighs basically nothing in such a small volumes.
Yes ultra high pressures create stiffer bumpier ride, but underpressured wheels on the other hand create wobly unstable ones. Thats the whole point of having ideal pressures for tires. As a guy up mentioned the ideal pressure for these conditions is around 60-65 PSI for 32 mm.
The charts were the same and do not show a 10w benefit for 28 vs 32 at 40km/hr. Both were 343 w
Yea, this confused me as well, did they typo in editing?
Yeah, I was confused by the data there too.
Hi Richard, good spot. The 28mm should have said 331W!
Yes, and he also SAID the same numbers, except at the end he didn't state out loud what the 32mm 40kmph watt avg, they just showed it on the screen. Another commenter asked the same and CGN rep said the 28kmph wattage was 331w, completely different to what the guy said in the video. Really, when you make a video specifically to talk about these numbers, shouldn't the editor check and double check the numbers and what gets said before actually posting it to youtube?!?!
I feel the same dogma that pushed us into 22mm tyres without any scientific thought still prevails in clipless pedals. Would love to see you challenge some of what I see as myths around SPD vs SPD-SL. What has the size of the pedal got to do with contact area with your foot when both affix to a shoe (which is the contact point and SPD shoes tend to have a metal plate at this point)? Why does a shoe need to be bone stiff all the way to the heel for power transfer? Where’s the power loss in flex and how much power are you putting down anywhere but the ball?
It's less "without any scientific thought" and more of a greater understanding of the physics behind what we know about tires. In addition, we have a greater variety of rubber compounds to use on tires, giving us more options than what we've had in the past.
As for pedals, from an amateur's eye, it would seem that road pedals are designed for long rides without too much variation in direction and terrain or too much getting off the bike (if at all). Road biking is all about repetition and optimization, after all.
On the other hand, MTB pedals are designed around multiple surfaces and the inevitable hopping off the bike and walking/running down difficult terrain. Hence, why cylcocross bikes use MTB pedals and not road pedals.
It's not "which is more effective" but what's more effective for which activity? It's like comparing running shoes versus trail running shoes.
@@zenspeed404 I don’t disagree they are designed for a specific purpose, I’m just asking the question are SPD-SLs really any better than SPDs for road use. I’m happy to be proven wrong but i’ve not seen anyone go in depth on this. My sense is people talk about power transfer and platform size when nobody has actually tested it. For e.g. we all know flexible frames are not any better for power transfer, simply sprinters prefer the feel and security of a stiffer frame. Perhaps people prefer stiff soled shoes but do they actually translate into better power transfer? Is the effective platform available to your foot actually bigger with SPD-SLs over SPDs?
I like SPD SL pedals because I find them easier to clip in and out. I have dual sided SPD/Platform pedals on my mountain bike and I always struggle with clipping in, although once in they work well.
@@davidhenry5925 fair enough, I wasn’t even aware of dual sided SLs! I personally find it the other way but I grew up riding SPDs on mountain bikes
@@eggeggeggegg I think from a power perspective it's the same but the comfort to bring this pressure onto the pedals changes a lot between spd-sl and SPD (but also heavily depending on the sole stiffness of the shoe and the construction of the pedal). If I do heavy pressure onto my SPD shoes/pedals, after some time I can feel that the pedal is not below the whole shoe and my feet bends with the shoe around the pedal. With the SPD-sl I do not have this feeling because the sole of the shoe is stiffer and the area of the pedal is much bigger.
32c tubeless on a Roubaix Expert with aFuture Shock 2.0…luxurious ride,better traction and less risk of bars getting knocked out of the hands.
This was a really good quality video, well done. A bunch of your earlier 'sciencey' videos were really not solid enough even for TH-cam, left more questions than they answered. But you explained the science well and performed a legit test/ demonstration. Must have been the lab coat. Well done
Makes you wonder when this was filmed if Si is wearing full longs.
It hasn't been cold enough for even arm warmers here in the UK for months!
But..Alex has post crash bandages on , Hmmmmm ???
Was cool on top of Mendip last week or two before latest heatwave, (recognise location just outside Priddy)
And there were some puddles. When was the last time it rained?!
Believe it or not it was last week!!
@@gcn Now I'm wondering if I live in a different dimension.
On longer distances and rougher tarmac, I found that front suspension +skinny tire is definitely faster than rigid fork +wider tire(@25-35kph). With the suspension I can also hold an aero position for longer, even on bumpy surfaces.
Great point, I run a 23 on the front with a suspension fork with a lockout for climbing and that is really comfortable with little of the jarring that narrow tyres usually give, the suspension fork adds weight but that doesnt bother me
Loving 30's on my Roval C38's!! I don't feel any faster with them, but I also do not feel any slower. The increased comfort on the bike is well worth the wider rubber & slight weight penalty!!
Yes, I agree... I moved up from 23mm to 25mm, not much difference in size but the comfort is greatly better. No loss in Speed vs Power. I am having a new set of wheels built with 32mm can't wait to sport these bad boys. "OORAH"
I just switched my Vittoria Corsa’s for the Conti’s 5k’s primarily cause my LBS was out of the VC’s… the first thing I noticed was the grip and handling of the bike… the VC’s with their wider tire profile were/had way more grip than the narrow Conti’s when going thru turns… and the ride felt smoother than the Conti’s… I just wish the VC’s were as puncture resistant as the Conti’s…
Definitely will change to bigger on my next replacements from 25C to at least 28 if not 32 with latex tubes. I am older and light so the benefit of less bumps through already stressed hands will be a blessing. I can ride at 40km/h but it quickly wears me out!
Very interesting topic, thanks GCN :) I ride 32 mm GP 5000, super happy!
One thing I would point out is that 45 psi for 32 mm tires was a bit too low for you, Sy. According to the Silca pressure calculator, the optimal pressure for 32 mm tires, 75-85 total weight, on "worn pavement" is ca 60 psi. 45 psi is for gravel, so on pavement it did slow you down.
According to the Rolling resistance webpage 32 mm tires have less rolling resistance than 28 mm at equal pressure, but similar resistance at equall comfort. You mentioned in the video that 32 mm tires felt more comfortable - so the pressure was indeed too low for this comparison. Fair comparison would be at equal pressure or at equal comfort. I'm really interested to see what would happen in these two cases, because in your test the aerodynamics is also considered. Is this an opportunity for Round 2? ;-)
My opinion is: 28 mm tires and narrower are optimal for light, fast riders (average > 40 km/h), who don't mind being less comfortable, who don't mind have a bit more punctures and ride on good pavement. Or they just like the look of narrow tires :)
Btw, you mentioned 10 watts of difference, but in the video you showed only 0.5 watts - which one is correct?
Tire width has nothing to do with punctures. Tire casing and tire design is the factor
@@markconnelly1806 You are right, width directly not, but the probability of pinch-flats is actually lower with wider tires (due to higher volume and higher profile), that was what I meant. But I agree that tire casing, design, material are more important.
@@markconnelly1806 But running a Wider Tyre at a reduced pressure should reduce punctures over a Narrower Tyre at a higher pressure
Try 28mm front and 32mm rear, which is what I did after watching this. Now I can be both fast AND comfy
Great stuff. It's tough for old dogs like me to learn new tricks...My new bike came with 26mm tires, I moved to 28mm (which were an improvement, particularly at lower pressures) and based on what you shared here, it's definitely time to try 32mm next.
Someone in the comment string probably already made this comment earlier, but rim width has a big impact on how well a wider tire is going to work with your bike, not to mention having enough frame clearance...which isn't a problem on my new road bike, but is definitely a problem on my 2007 vintage bike (25mm max clearance and skinny rims to boot, unfortunately).
I also experimented with running lower pressures on my old bike (80 PSI with 25mm tires) and suffered too many pinch flats as a result. My new wider rim / 28mm set up allows me to run much lower pressure (65 PSI) in spite of me weighing 170lbs, and in general I am experiencing far fewer flat tires, which is possibly the #1 upside out of the whole deal.
This experiment would have been more interesting to have two pressures for each tire wide. The vibration loss is dependent on road roughness. The tire pressure choice in the video may not be optimal for the given road condition. It may be that 32 mm at 60 psi has a lower resistance (power requirement) than 28 mm at 60 psi. Would be an interesting topic for the next video.
Absolutely
Yes need identical tire pressure in both tires. Bad test
I’ve been running wider tyres for a few years now. I’m currently using 35c as I love the comfort and versatility to mix up the surfaces I can venture into. Riding with my mates is harder when there is lots of surging but otherwise I love them. I started off with 32c when the GP5000s came onto the scene and they were great but wore out quickly, the 35c from Pirelli solved that issue. So much more comfort for not that much more noticeable effort 😊
I'm going to leave a comment on that above, but I too am doing 35c "slick" gravel, and keeping up with my biking group.
32c is best for current gen roadbikes.
The manufacturer's ulterior motive when forcing the trend to shift to wide tires was to make modern bicycles safer. Small tires are too dangerous for disc brakes because they lose traction easily. Safer is better than faster.
in motogp you can fall many times unscathed, but road cycling use public roads which are much more dangerous.
I rode the same 6km every day for several years, and regardless of mountain bike, road bike, gravel tires, 25c, 33c, the time was always 15 minutes +- a minute with no bike "winning". My position, winds, traffic were vastly more important than the tires.
Interesting real world test, thank you Si and co. I run 22mm Conti Comp tubulars on Campy Bora One 50s and yes, you might laugh but then the roads are beautifully smooth like a babies bum here in the mountains in Andalucía. Whereas, my wife runs 32mm GP5000 S TRs on a lightweight Langma as she doesn’t ride crazy fast but loves the grippiness, cornering confidence, stability and comfort they give. It shows that the road quality and nature of the rider are important factors in tyre choice.
Been using 28 for about 2half years and im pretty satisfied with the experience, im using a 1988 raleigh racer bike and 28mm tires work great at long rides.
Btw… use Silca calculator for air pressure… I think you should have go more in the 60-62 PSI range.
Yeah, I checked the silca and 45psi is too little I think. Under 60psi I'm aftaid of getting pinch flat every moment.
Silca calculator seems biased on the high side…
Keep in mind that wider rims should drop your recommended pressure.
@@diegoleiva7242 yeah maybe, but not 40%…
@@discbrakefan I don’t know man, I experimented a lot.. riding SLR 1 wheels from Giant, 24mm inner I think.. 32 min tyres.. going below 60 psi feels too plushy and bouncy.. My system weight is around 94kg total… I tried with 50 psi and just sitting on the bike, the rear tyre looks too flat..
I've been riding 25's and there harsh..After watching this video I'm going to try the N.EXT in 30mm!..The sweet spot! 😵💫
My new Trek came with 32c tubeless tires, and it's made me so much happier riding. The increased comfort and the feel of increased stability makes a night and day difference. I don't feel any slower at all compared to my old 25c tube tires on my older bike. Couldn't recommend wider tires more to anyone who will listen.
I just switched from 25mm to a 28 mm front and 32mm rear, never going back to narrower tires, the comfort and stability far outweigh whatever the speed difference is.
I started running big chunky boy 35 mm Continental GP urbans on my 25mm internal rim width wheel set and I love it! So comfortable, and I keep setting PR's on my strava. I'm a fan and convert of bigger, wider tires. All about that comfort
Just be aware of the very narrow tread the GP Urbans have. On those wide rims the sidewalls balloon out way past the tread area, and the sidewalls are very weak.apart from that its a lovely comfy relatively puncture resistent fast tire for a modern endurance road bike.
GCN Science in eastern Iowa…recently did B2B 39 mile (62.7 km) pavement route (2.5 miles gravel) with 1800 ft elevation (its Iowa, so rolling hills…max 1 minute climbs). Weather was similar with a bit more exposure to light headwind on the 2nd day. 1st Day on Specialized Crux (2018) with 32mm (34 measured on 22.5i) GP5K TL’s at 45F/50R psi. 2nd day on Specialized Diverge with 44mm (44 measured on 25i) RH Snoqualmie’s at 37F/42R psi (usually 32/37 for gravel). Both set up tubeless. Both bikes have the same model Quarq PM. I’m 190 lbs/86kg. Both bikes run SRAM AXS 46/33 front, 10-28 Crux, 10-33 Diverge. Rode by PE (totally nonSCIENTIFIC). Results, Crux 2:17:17. Diverge 2:16:53. 24 seconds total separated the two rides. Approximately 17 mph/27 kph average speed (on the back end of Covid so wasn’t going for gold) Metrics: average cadence 84 on both rides. Ave HR 141 on Crux/32’s, 146 on Diverge/44. NP 172 on Crux, 187 on Diverge. Effort “felt” similar between both rides. What do these numbers mean…probably not a whole lot, but fun doing these completely non-scientific comparisons. BTW, 32mm FTW on pavement rides. Don’t think I’ll ever go narrower ever again.
I started with 23 and now running a 32. I would say 23 is of course faster but I love the comfort and versatility that 32 provides. I don't think I would fo higher than 32 though (would just switch bike to my MTB)
I’m on 32mm, came stock on my bike.. feels good speed wise.. I’m not racing tbh, just look at power, stoped caring about speed at all.
Alex doing a ‘sniff test’! Gross but hilarious…. Entertainment with science! You boys spoil us mere mortals ……
😵💫
Hi! I still use 28 tubeless, but with new wide rims. Anyway, I think that if you make a test with a peloton the numbers will turn in favor of the 32. The extra drag will be mitigated and the benefits in comfort will pay of in long stages. Thinner tires (in this new standards) will probably continue to show up in TT Stages, at least on the front wheels.
I'm riding 28 mm tyres for almost 6 years now (Hutchinson sector 28) and I'm not slower than with the 'standard' 23 mm tyres I used before. What I like is the comfort the 28's bring. Since I ride a gravel bike which is fitted with a 650b wheelset with 47 mm Vittoria Terreno Zero's I almost didn't use my pure road wheelset anymore. I'm not measurable slower with the much wider tyres and the amount of grip with even more comfort let me take these wheels as my first choice for almost all of my rides. The wider tyres feel just a little bit slower in accelerating and that's why when I'm riding in a group makes me choose the narrower 28's, all my other rides are with the widest tyres my bike can fit.
The fastest tyre at 40kmph will likely be the one that matches the aero profile of your wheel. So you need to do this experiment again with wider wheel rims for the 32mm tyres.
I went from 23mm & 25mm to 28mm tyres on my road bike and I’ve never looked back. The improvement in comfort is sublime and I’ve gained a bit of speed too as I’m far more comfortable than I was on the thinner tyres 👍🏾
If you tune the bike, it won't be as good in other areas.
@@Gma7788 ? The point of tuning anything is aiming to improve things overall……isn’t it?
Changed from 28mm to 30mm after the 28’s wore out. Love the increased comfort. Not tubeless and no flats for the past 3000 K’s. Never going back 😊
Do you ride a racing bike?
Are you using rim brakes or disk brakes? I'm wondering if 30mm tyres (looking at the schwalbe G one speed) would fit the Shimano 105 R7000 rim brake caliper. I know the spec sheet says it is compatible up to 28mm.
What about 28 rear & 25 front? Or even 30 rear 28 front? More comfort under the saddle but the front not numbed down too much to keep agile steering.
I have only used 28mm and now i am open to trying something wider. Great video.
I run 25mm on my bike. I tried 28mm as there was plenty of room between the width of the forks but the tyres were too close to the underside of the fork crown. The smallest piece of gravel would jam in the gap and have me sailing over the 'bars!
So a tiny piece of gravel would jam your wheel. Hahah.
I was riding 28mm and switched to 25mm. I found no big change in comfort, but it’s much easier to slip the tire in through my rim brakes and the smaller spare tube takes up less space in my saddle bag.
In my experience if out and out speed is what you value most a 25mm tyre is better as it makes for a lighter more responsive wheelset. If you value comfort and grip more then the 32mm tyres are better and only sacrifice about 1-1.5mph average speed.
I assume you’re saying the 1 -1.5 mph average speed sacrifice going from 25 to 32 is your experience when calculating type of road hills and wind as opposed to just a flat road the above test was made with? What is been your experience with the difference in speeds uphill 25 mm to 32 mm?
Good video as always. I ride on 32 mm tubeless tires and I ride 60 psi in the front, and 65 psi in the back. It’s a nice and comfortable ride..
I bought a hybrid with 28 on but as I tend to use for road and Forest I put 40mm on and they are great, like thick slicks
You'll find even bigger gains if you compared 25s. Way more aerodynamic than 32s. The move to wider rims and tyres is mostly fashion and to compensate for harsh frame design. I agree they are perhaps a good idea on UK roads. Another point is that tubeless is great for MTBs with high volume and low pressure, but on road, even with 32s it doesn't work well at all. The tyre goes down too quickly for the hole to seal, makes a mess and is a faff compared to just putting in a new tube.
If wider is just a fashion statement then TdF racers would be using 28mm instead of 25mm.
Having the 28 mm on my Roti has been a really cool experience but I definitely see myself going to a 32 just to check it out
how was it?
Glad to see that Vittoria and the cycling world in general is catching up, riding on the coattails of René Herse's Jan Heine's pioneering research! Wide tires aren't necessarily slower. Real world results keep confirming this. Great video gcn. How about getting Jan on for an interview?
Jan Heine has pioneered nothing and does no research. He exclusively recreates cycling from the 50's, nothing more.
I'm impressed how strong you both rode despite the illness leading up to the event. Eating and resting conquers races! Syd is riding so much stronger compared to 1 year ago.