Narrow vs wide tyres - Bring data

[warthog101]

I've read the thread and am not reading evidence supporting the use of narrow tyres unless you are also running narrow rims.
Plenty of evidence that wider rims and tyres get results.
You appear to have your mind set on narrow is best. Enjoy.

[Nereth]

I feel like the first few pages did a decent job of laying out the conditions under which 25mm fronts should be considered.

Then I skipped 10 pages. But I haven't been told much changed.

A bit of interesting discussion about tyre construction since, and then people pointing to pros, which I find decidedly unhelpful as their motivations and reasoning are entirely unclear and even purposefully obfuscated much of the time.

I'd concede that if you're the kind of rider where the interesting part of the ride is the climb (or your roads are rough, or you don't go that fast), then a narrow front setup is probably not for you.

[Requiem84]

Uhhh sorry guys, how long do GC contenders spend at 45kph+ in the wind during a tour stage?

Are those the critical moments for them?

How about those climbing records? Is he climbing at 45kph?

By contrast, how long do they spend climbing at 15-30kph or sitting in a massive draft from the peloton or their domestiques?

Other than on TT stages, GC contenders tyre choices are not going to be driven by aero.

On a TT stage, I would note that the Enve front TT wheel (enve 7. is still 19mm internal so... have we got any info on what they rode on TT stages?

This whole "but the pros" thing is an appeal to authority anyway - not the "bring data" philogophy that I had hoped this thread would aspire to.

Pogacar made his first big gap (35seconds) on a 20km solo descend going 65 km/h average.

I think the data you provided is that narrower is 1-2watt faster in Cda.

I have no reason to distrist the sources you cite, so I have to agree. Learned something new, which is interesting and which is why I am here. I am not here to show I'm smarter or that I have the sole truth, because I won't convince anyone who has strong beliefs anyway.

As for basically the entire peloton going wider, I think the conclusion 'it's all sponsors' is too simplistic. Especially for the top teams like Visma lease a bike. Their main sponsor is Pon (who owns Lease a bike). Both Cervelo and Reserve are owned by Pon. The 42/49 reserves have been developped by Visma, specced by their joint wind tunnel research. Front wheel is 25.3 IW and 34.4 EW. Vittoria is now providing them prototype 29mm tires.

The only conclusion from these kind of developments is that the aero gain of 1-2watts is marginal at best and that going wider on both rim and tire apparently offers other tangible benefits outweighing the 2 watts lost aerodynamically.

[cajer]

Uhhh sorry guys, how long do GC contenders spend at 45kph+ in the wind during a tour stage?

Are those the critical moments for them?

How about those climbing records? Is he climbing at 45kph?

By contrast, how long do they spend climbing at 15-30kph or sitting in a massive draft from the peloton or their domestiques?

Other than on TT stages, GC contenders tyre choices are not going to be driven by aero.

On a TT stage, I would note that the Enve front TT wheel (enve 7. is still 19mm internal so... have we got any info on what they rode on TT stages?

This whole "but the pros" thing is an appeal to authority anyway - not the "bring data" philogophy that I had hoped this thread would aspire to.

Pogacar made his first big gap (35seconds) on a 20km solo descend going 65 km/h average.

I think the data you provided is that narrower is 1-2watt faster in Cda.

I have no reason to distrist the sources you cite, so I have to agree. Learned something new, which is interesting and which is why I am here. I am not here to show I'm smarter or that I have the sole truth, because I won't convince anyone who has strong beliefs anyway.

As for basically the entire peloton going wider, I think the conclusion 'it's all sponsors' is too simplistic. Especially for the top teams like Visma lease a bike. Their main sponsor is Pon (who owns Lease a bike). Both Cervelo and Reserve are owned by Pon. The 42/49 reserves have been developped by Visma, specced by their joint wind tunnel research. Front wheel is 25.3 IW and 34.4 EW. Vittoria is now providing them prototype 29mm tires.

The only conclusion from these kind of developments is that the aero gain of 1-2watts is marginal at best and that going wider on both rim and tire apparently offers other tangible benefits outweighing the 2 watts lost aerodynamically.

I will post a severely shortened version of what I posted on slow twitch. Sponsors have a very large vested interest in going wider tire wise. Making pros go wider gives the average user desire to buy new equipment. When UCI mandates that hookless on enve Zipp or other 25mm Id tires Asher to etrto standards riders are forced to use 29mm+ tires. Many companies don't make 29mm tires to they end up on 30mm.

At the end of the day the people with the money speak. Pro have always done stupid things, such as discount aero, ride stupidly narrow tires 19mm after using 22mm in the past, and stick to slower tubulars. I believe there's actually a pro team still using tubulars in the tour this year or last year.

You should stop saying what do the pros ride and bring data or first principles derived knowledge.

[Requiem84]

Uhhh sorry guys, how long do GC contenders spend at 45kph+ in the wind during a tour stage?

Are those the critical moments for them?

How about those climbing records? Is he climbing at 45kph?

By contrast, how long do they spend climbing at 15-30kph or sitting in a massive draft from the peloton or their domestiques?

Other than on TT stages, GC contenders tyre choices are not going to be driven by aero.

On a TT stage, I would note that the Enve front TT wheel (enve 7. is still 19mm internal so... have we got any info on what they rode on TT stages?

This whole "but the pros" thing is an appeal to authority anyway - not the "bring data" philogophy that I had hoped this thread would aspire to.

You should stop saying what do the pros ride and bring data or first principles derived knowledge.

I already did - see PT testing brought up by me which is confirmed by wind tunnel testing mentioned on page 1.

I think we all agree that 25mm has a lower Cda than 28mm by 1 to max 2 watt.

If the story ends there for you, be happy and ride 25mm.

[cajer]

Ok so you dismiss everything I say about your previous point... despite me pointing out why they have a 29mm tried made for them. Because that's the only width they are allowed to use.

Other than grip there's been no clean evidence for any other benefit.

[Requiem84]

Ok so you dismiss everything I say about your previous point... despite me pointing out why they have a 29mm tried made for them. Because that's the only width they are allowed to use.

Other than grip there's been no clean evidence for any other benefit.

Entire UAE is riding on 28mm (apart from Pog).

Visma lease a bike developed the 25.5 IW wheel together with Reserve. They rode both 28mm regular Corsa Pro and the 29mm prototype tyre. So no, the 29 isn't made for UAE nor for Visma. If you want to raise a point, please make sure you check the facts.

By the way, their TT bike also has 25mm IW (and 38mm (!) EW. Recommended tires are 28-32mm on these wheels.

Again, these are developped by the Pro cycling team that is crazy about marginal gains and which has the same owner as their title sponsor.

But I guess they just chose to ride slow tires because of eh yeah sponsor money.

[cajer]

Ok so you dismiss everything I say about your previous point... despite me pointing out why they have a 29mm tried made for them. Because that's the only width they are allowed to use.

Other than grip there's been no clean evidence for any other benefit.

Entire UAE is riding on 28mm (apart from Pog).

Visma lease a bike developed the 25.5 IW wheel together with Reserve. They rode both 28mm regular Corsa Pro and the 29mm prototype tyre. So no, the 29 isn't made for UAE nor for Visma. If you want to raise a point, please make sure you check the facts.

By the way, their TT bike also has 25mm IW (and 38mm (!) EW. Recommended tires are 28-32mm on these wheels.

Again, these are developped by the Pro cycling team that is crazy about marginal gains and which has the same owner as their title sponsor.

But I guess they just chose to ride slow tires because of eh yeah sponsor money.

Maybe there was another newer uci mandate. But the latest one I could find from the end of March says they need to follow iso standards which is 29mm for a hookless 25mm wheel. So either things have changed or there was a wavier

https://www.uci.org/pressrelease/use-of ... Q2d7bAiRy7

[BenCousins]

Did you know pros are forced to wear white shoes by sponsors?

[warthog101]

Ok so you dismiss everything I say about your previous point... despite me pointing out why they have a 29mm tried made for them. Because that's the only width they are allowed to use.

Other than grip there's been no clean evidence for any other benefit.

Entire UAE is riding on 28mm (apart from Pog).

Visma lease a bike developed the 25.5 IW wheel together with Reserve. They rode both 28mm regular Corsa Pro and the 29mm prototype tyre. So no, the 29 isn't made for UAE nor for Visma. If you want to raise a point, please make sure you check the facts.

By the way, their TT bike also has 25mm IW (and 38mm (!) EW. Recommended tires are 28-32mm on these wheels.

Again, these are developped by the Pro cycling team that is crazy about marginal gains and which has the same owner as their title sponsor.

But I guess they just chose to ride slow tires because of eh yeah sponsor money.

I had a bit of a look for performance data on wider wheels and tyres. There was none that I found. All there is, is what the teams are using and the results.
They are heavily in favour of wider wheels and tyres.
Riding wider wheels and tyres clearly is not going to impinge on your speed given the speed at which the tour is raced at.
Use data to feel better on your narrower front tyres ( the point of the thread ) or ride wider and know that there is no speed penalty but other advantages. Comfort and grip being two.

[maxim809]

It's not data, and not Road. But some history on disc brakes from Josh@Silca.

Question asked by Velochumps @ 40min:
"By removing the rim brake caliper, do you think this caused wheel and tire manufacturers to move too fast and too divergently? Such that even the enthusiasts don't know which rim to run with which tire at which pressure?"

Following are Highlights of Josh's answer:

- We wanted to win Roubaix in 2007-2008 using Carbon wheels.
- Common Wisdom in 2007/2008 for Roubaix was 24mm Dry, 27mm Wet
- By lower the pressure on the cobbles, the riders were going faster and faster.
- Everyone back then air-quote "knows" higher PSI is faster, yet lowering pressure for comfort made racers faster.
- Everyone was confused.
- Discovered very quickly during the study that they just need bigger tires at the right pressure.

- So if 27mm are faster because you can run them lower, what about 30mm?
- They custom printed drop-out pieces to precisely allow 30mm tires to clear the fork & crown. It was WAY faster.
- So what about 32mm? 34mm?

There was no way to make these tires fit on rim. Why not just make bigger rim brakes? The problem with rim is it's only effective in leverage within a really small range (few mm). If the rim gets wider and the calipers wider, you can't put bigger wheels back in nor put smaller wheels back in. The disc brake freed this constraint of having to know the rim shape. Don't need to know if wide or narrow.

And MTB already solved this problem, and this tech was already mature.

Long story short the people in the room who discovered wider tires are faster, knew bigger tires were the future and they couldn't get there with rim brakes. Gerard Vroomen who was in the room with Josh, went on to sell Cervelo, co-founded OPEN, and essentially made the first gravel bike. Which is also actually a large clearance road bike with disc brakes.

So really, the tires actually drove the disc brake movement. NOT the other way around.

On the flip side, when they were able to get repeatable results with wider tires and specific pressure, at that moment they realized they knew something nobody else knew. "We locked that knowledge down with a tight group". Tire width and tire pressure was the best kept secret, so much that they were mislabeling the tires and they did that all the way up to Peter Sagan winning Roubaix in 2018. He won on 32's labelled as 30's. Everyone asks what widths and PSIs are you all riding. And the best part is they are all lying. "The story is largely obscured, because we obscured it."

Suddenly one day, wide tires was all over the magazines. It had become conventional wisdom, so much so that conventional wisdom was starting to become wrong. People were coming to Josh saying, "Your tire pressure calculator is wrong. It's too high! Don't you know lower pressure is faster?" Silca's calculator is the only one based on real data.

So we've come full circle. Like anything it's the adoption curve and the trickle down effect. Bleeding edge technology people get it first. Early adopters pick it up next. Then the average person starts getting it. Roughly it's a 10 year cycle.

Starts at ~41minutes:
https://podcasts.apple.com/us/podcast/v ... 0613316911

[Kubackjeee]

Uhhh sorry guys, how long do GC contenders spend at 45kph+ in the wind during a tour stage?

Are those the critical moments for them?

How about those climbing records? Is he climbing at 45kph?

By contrast, how long do they spend climbing at 15-30kph or sitting in a massive draft from the peloton or their domestiques?

Other than on TT stages, GC contenders tyre choices are not going to be driven by aero.

On a TT stage, I would note that the Enve front TT wheel (enve 7. is still 19mm internal so... have we got any info on what they rode on TT stages?

This whole "but the pros" thing is an appeal to authority anyway - not the "bring data" philogophy that I had hoped this thread would aspire to.

Following this stupid logic only GC contenders should be running wide tires and all the lead out guys should be on 25

[Lina]

It's not data, and not Road. But some history on disc brakes from Josh@Silca.

Question asked by Velochumps @ 40min:
"By removing the rim brake caliper, do you think this caused wheel and tire manufacturers to move too fast and too divergently? Such that even the enthusiasts don't know which rim to run with which tire at which pressure?"

Following are Highlights of Josh's answer:

- We wanted to win Roubaix in 2007-2008 using Carbon wheels.
- Common Wisdom in 2007/2008 for Roubaix was 24mm Dry, 27mm Wet
- By lower the pressure on the cobbles, the riders were going faster and faster.
- Everyone back then air-quote "knows" higher PSI is faster, yet lowering pressure for comfort made racers faster.
- Everyone was confused.
- Discovered very quickly during the study that they just need bigger tires at the right pressure.

- So if 27mm are faster because you can run them lower, what about 30mm?
- They custom printed drop-out pieces to precisely allow 30mm tires to clear the fork & crown. It was WAY faster.
- So what about 32mm? 34mm?

There was no way to make these tires fit on rim. Why not just make bigger rim brakes? The problem with rim is it's only effective in leverage within a really small range (few mm). If the rim gets wider and the calipers wider, you can't put bigger wheels back in nor put smaller wheels back in. The disc brake freed this constraint of having to know the rim shape. Don't need to know if wide or narrow.

And MTB already solved this problem, and this tech was already mature.

Long story short the people in the room who discovered wider tires are faster, knew bigger tires were the future and they couldn't get there with rim brakes. Gerard Vroomen who was in the room with Josh, went on to sell Cervelo, co-founded OPEN, and essentially made the first gravel bike. Which is also actually a large clearance road bike with disc brakes.

So really, the tires actually drove the disc brake movement. NOT the other way around.

On the flip side, when they were able to get repeatable results with wider tires and specific pressure, at that moment they realized they knew something nobody else knew. "We locked that knowledge down with a tight group". Tire width and tire pressure was the best kept secret, so much that they were mislabeling the tires and they did that all the way up to Peter Sagan winning Roubaix in 2018. He won on 32's labelled as 30's. Everyone asks what widths and PSIs are you all riding. And the best part is they are all lying. "The story is largely obscured, because we obscured it."

Suddenly one day, wide tires was all over the magazines. It had become conventional wisdom, so much so that conventional wisdom was starting to become wrong. People were coming to Josh saying, "Your tire pressure calculator is wrong. It's too high! Don't you know lower pressure is faster?" Silca's calculator is the only one based on real data.

So we've come full circle. Like anything it's the adoption curve and the trickle down effect. Bleeding edge technology people get it first. Early adopters pick it up next. Then the average person starts getting it. Roughly it's a 10 year cycle.

Starts at ~41minutes:
https://podcasts.apple.com/us/podcast/v ... 0613316911

Also more from Josh, mostly hookless discussion but there's also this paragraph. https://www.slowtwitch.com/Products/Thi ... _8710.html

Case in point, the setup that has most excited me in the last few years is a 32mm Continental GP5000TR on the 3T Discus 45/40 rim. This is a 32mm tire on 29mm hooked bead with 40mm outer rim width, totally in violation of ETRTO, but exceeds the blowoff pressure of the same tire on an ETRTO approved 25mm hookless bead. In this setup the tire measures 35.5mm wide and produces a near seamless toroidal rim/tire shape which tests lower drag than most any traditional road racing wheel with 25 or 28mm tire while also showing some of the most neutral aero steering torque values of any setup I've ever seen.

Why we don't have public data about this is because pretty much everyone that has this data is keeping it on a need to know basis.

[jlok]

Uhhh sorry guys, how long do GC contenders spend at 45kph+ in the wind during a tour stage?

Are those the critical moments for them?

How about those climbing records? Is he climbing at 45kph?

By contrast, how long do they spend climbing at 15-30kph or sitting in a massive draft from the peloton or their domestiques?

Other than on TT stages, GC contenders tyre choices are not going to be driven by aero.

On a TT stage, I would note that the Enve front TT wheel (enve 7. is still 19mm internal so... have we got any info on what they rode on TT stages?

This whole "but the pros" thing is an appeal to authority anyway - not the "bring data" philogophy that I had hoped this thread would aspire to.

Following this stupid logic only GC contenders should be running wide tires and all the lead out guys should be on 25

Every GC contender should ride V4rs and Enve wheels; also note that SRAM is second best.

[blutto]

It's not data, and not Road. But some history on disc brakes from Josh@Silca.

Question asked by Velochumps @ 40min:
"By removing the rim brake caliper, do you think this caused wheel and tire manufacturers to move too fast and too divergently? Such that even the enthusiasts don't know which rim to run with which tire at which pressure?"

Following are Highlights of Josh's answer:

- We wanted to win Roubaix in 2007-2008 using Carbon wheels.
- Common Wisdom in 2007/2008 for Roubaix was 24mm Dry, 27mm Wet
- By lower the pressure on the cobbles, the riders were going faster and faster.
- Everyone back then air-quote "knows" higher PSI is faster, yet lowering pressure for comfort made racers faster.
- Everyone was confused.
- Discovered very quickly during the study that they just need bigger tires at the right pressure.

- So if 27mm are faster because you can run them lower, what about 30mm?
- They custom printed drop-out pieces to precisely allow 30mm tires to clear the fork & crown. It was WAY faster.
- So what about 32mm? 34mm?

There was no way to make these tires fit on rim. Why not just make bigger rim brakes? The problem with rim is it's only effective in leverage within a really small range (few mm). If the rim gets wider and the calipers wider, you can't put bigger wheels back in nor put smaller wheels back in. The disc brake freed this constraint of having to know the rim shape. Don't need to know if wide or narrow.

And MTB already solved this problem, and this tech was already mature.

Long story short the people in the room who discovered wider tires are faster, knew bigger tires were the future and they couldn't get there with rim brakes. Gerard Vroomen who was in the room with Josh, went on to sell Cervelo, co-founded OPEN, and essentially made the first gravel bike. Which is also actually a large clearance road bike with disc brakes.

So really, the tires actually drove the disc brake movement. NOT the other way around.

On the flip side, when they were able to get repeatable results with wider tires and specific pressure, at that moment they realized they knew something nobody else knew. "We locked that knowledge down with a tight group". Tire width and tire pressure was the best kept secret, so much that they were mislabeling the tires and they did that all the way up to Peter Sagan winning Roubaix in 2018. He won on 32's labelled as 30's. Everyone asks what widths and PSIs are you all riding. And the best part is they are all lying. "The story is largely obscured, because we obscured it."

Suddenly one day, wide tires was all over the magazines. It had become conventional wisdom, so much so that conventional wisdom was starting to become wrong. People were coming to Josh saying, "Your tire pressure calculator is wrong. It's too high! Don't you know lower pressure is faster?" Silca's calculator is the only one based on real data.

So we've come full circle. Like anything it's the adoption curve and the trickle down effect. Bleeding edge technology people get it first. Early adopters pick it up next. Then the average person starts getting it. Roughly it's a 10 year cycle.

Starts at ~41minutes:
https://podcasts.apple.com/us/podcast/v ... 0613316911

Also more from Josh, mostly hookless discussion but there's also this paragraph. https://www.slowtwitch.com/Products/Thi ... _8710.html

Case in point, the setup that has most excited me in the last few years is a 32mm Continental GP5000TR on the 3T Discus 45/40 rim. This is a 32mm tire on 29mm hooked bead with 40mm outer rim width, totally in violation of ETRTO, but exceeds the blowoff pressure of the same tire on an ETRTO approved 25mm hookless bead. In this setup the tire measures 35.5mm wide and produces a near seamless toroidal rim/tire shape which tests lower drag than most any traditional road racing wheel with 25 or 28mm tire while also showing some of the most neutral aero steering torque values of any setup I've ever seen.

Why we don't have public data about this is because pretty much everyone that has this data is keeping it on a need to know basis.

Gosh that is a great story (especially the bolded bit that the story pivots on ), don't you just love it when the marketing men tell stories.

Small problem, that story is not quite as presented. When I started racing wider tubulars were available and ubiquitous in the peloton ( and smaller tubs like the 19mm and 22mm tubs, the current whipping boys, were very rare ) And braking systems usually came in two reaches with the longer ones easily accomodating 40mm tires ( tourists often used tyres in that range and yes the brakes used back then did have significant leverage since they were typically used to stop fully loaded tourist bikes and/or tourist tandems ). Simple bolt based systems were used to change brake width to accomodate rim width differences and there were these mechanisms called quick releases to allow wheels to be taken out.

The bigger insurmountable problem is actually the modern height of the brake bridge and the length of the fork blades and not necessarily the brakes ( and that wider solution had already been available and widely used for several decades past....as btw had the availability of disc brakes for road bikes which not many bothered with since the right marketing ploy had not yet been launched to make them an indispensible part of every bike ).

Cheers