GCN and BQ join forces!

[bicycletricycle]

it is a slow day, lets talk about tires!!!!!

I guess wide tires really aren't slower? but for real this time? Or ????

I don't have a lot to say on this one other than that I am so slow it doesn't matter and wide tires are so comfy

I would be cool to see the same bicycle and tires tested real world like this, then in the computer to see if the two could be correlated.

https://www.renehersecycles.com/glob...fast-as-26-mm/

https://www.youtube.com/watch?v=AK5KLvrzrb4&t=1s

[litcrazy]

Like you, I'm a sucker for the comfort of larger tires in many cases and wouldn't mind a modest loss of speed. I started my evolution towards wider tires back when Rivendell was selling the wide-tire koolaid based on comfort alone. But I've also been pleased by how much slower they aren't in my unscientific experience.

Knowing the passion this subject and Jan ellcits here, I was waiting for the start of this thread after reading Jan's email this morning as GCN would seem to offer some of the evidence folks have been demanding.

[bicycletricycle]

Ah, The Grant -> Jan old curmudgeon pipeline. I have been on a similar journey although I started with the Riv reader when i was 18 or something, I guess I am wise beyond my years.

Remember when 28mm tires were big? Now pros ride those on time trials and on the f'ing track!!!!!

Originally Posted by litcrazy

Like you, I'm a sucker for the comfort of larger tires in many cases and wouldn't mind a modest loss of speed. I started my evolution towards wider tires back when Rivendell was selling the wide-tire koolaid based on comfort alone. But I've also been pleased by how much slower they aren't in my unscientific experience.

Knowing the passion this subject and Jan ellcits here, I was waiting for the start of this thread after reading Jan's email this morning as GCN would seem to offer some of the evidence folks have been demanding.

[Mark McM]

Originally Posted by bicycletricycle

Remember when 28mm tires were big? Now pros ride those on time trials and on the f'ing track!!!!!

Well, maybe not on the track. You're not likely to see any top class track racers riding anything wider than 23mm tire. Indoor tracks are so smooth that there's no benefit to using a wider tire. Even outdoors, 25mm tires still more the standard for TTs (although these tires inflate out to more like 26mm or 27mm on wide rims).

In a recent Escape Collective Performance Process podcast, JP Ballard of Swiss Side said due to using wider tires, rims have been getting wider, but that there is a certain point when the increased aero drag (from increased frontal area) becomes a net deficit. He put this width around 30mm (at 45 kph). Since we know that at slower speeds, aero matters less, the cross-over width for most riders will likely be wider.

[BrazAd]

I’m a big guy - 6’-2”, 225-230 lbs.

I just got a new road bike that I put 30mm tires on. My previous road bike was wearing 28mm.

I’ve dropped my tire pressure, the ride is SMOOTH and there’s been no struggle with speed, either riding solo or with my regular group.

What’s not to love?

Gary


Sent from my iPhone using Tapatalk

[bicycletricycle]

Originally Posted by Mark McM

Well, maybe not on the track. You're not likely to see any top class track racers riding anything wider than 23mm tire. Indoor tracks are so smooth that there's no benefit to using a wider tire. Even outdoors, 25mm tires still more the standard for TTs (although these tires inflate out to more like 26mm or 27mm on wide rims).

In a recent Escape Collective Performance Process podcast, JP Ballard of Swiss Side said due to using wider tires, rims have been getting wider, but that there is a certain point when the increased aero drag (from increased frontal area) becomes a net deficit. He put this width around 30mm (at 45 kph). Since we know that at slower speeds, aero matters less, the cross-over width for most riders will likely be wider.

A tire that inflates to 27 is a 27? I think I saw a reference for wide tires on the track, I’ll see if I can find it

Dan Brigham running 27.5 measured tires on hour record attempt

[m_sasso]

Originally Posted by bicycletricycle

A tire that inflates to 27 is a 27? I think I saw a reference for wide tires on the track, I’ll see if I can find it

Dan Brigham running 27.5 measured tires on hour record attempt

Don't know where you are getting your info from, however from https://www.rouleur.cc/blogs/the-rou...ecord-part-two

"We also used a 25mm Continental GP5000 TT tyre but when they’re installed measure about 27mm. They’re quite a bit bigger than the usual 19s and 23s you see on the track (and the 23s I used last year)."

[bicycletricycle]

Originally Posted by m_sasso

Don't know where you are getting your info from, however from https://www.rouleur.cc/blogs/the-rou...ecord-part-two

"We also used a 25mm Continental GP5000 TT tyre but when they’re installed measure about 27mm. They’re quite a bit bigger than the usual 19s and 23s you see on the track (and the 23s I used last year)."

https://youtu.be/SF0DHYW-HOM?feature=shared
Minute 19 ish

Also, 25mm that measure 27mm are 27mm tires. The interview above says 27.5 actual measure

[Mark McM]

Originally Posted by bicycletricycle

Also, 25mm that measure 27mm are 27mm tires. The interview above says 27.5 actual measure

Well, not exactly. Because if 25mm tires were actually 27mm tire, then they would also be 23mm tires.

A clincher tire casing does not create a complete pressure vessel, so its inflated width depends on the rim it is mounted on. The labeled width of a tire is based on being installed on a reference rim. If you install the tire on a rim wider than the reference rim, it will inflate wider the label width, and if you install the tire on a rim narrower than the reference rim, it will inflate narrower than the label width. Currently, ETRTO says you can install a 25mm tire on a rim width from 15 mm - 23mm, although previously they said 13 mm - 17mm. A tire labeled 25mm will inflate to an actual 25mm width on a rim about 17mm wide. On a 13mm rim they will be closer to 23mm, and on a 21mm rim they will be about 27mm.

So, the answer to "how wide is a 25mm tire" is similar to the answer for "how long is a piece of string."

[litcrazy]

I think when discussing whether wider tires are faster, it makes sense to discuss the measured width. That captures the shift in the peloton. It also captures the shift in comfort. To say a tire is 23 that measured 27 would indicate that there hadn’t been a change that is well documented from the days of racers running undersized 23s.

I’ve had enough variance between brands and between models within brands to feel that it’s really not useful to invoke reference rim width because that only attends to a part of the variance. It’s a bit like discussing nba player heights before they tried to standardize measurements or looking at weights on drivers licenses for a study on bmi.

[Elefantino]

I used to hear, "How can you ride 23s?"

Now I hear, "How can you ride 25s?"

[lorenbike]

Originally Posted by Elefantino

I used to hear, "How can you ride 23s?"

Now I hear, "How can you ride 25s?"

No interest in riding tires <28mm. And I'm a fan of vintage steel frame/fork bikes with quill stems for more plushness.

From anecdotal experience, I don't think you give much up on the 'road' feel until you get to ~38mm.

[bicycletricycle]

This is a weird post Mark
Everyone knows this.
Doesn’t really mean much though.

I say actual measured width when mounted on your set up is a more important piece of information than what the tire says on the side. You disagree?

When we have real tire on a real rim it isn’t “how long is a piece of string” it is grab some calipers and measure your tire.

The actual measured width tells us more about all the things we might want to know (volume, aerodynamics and contact patch). It is in no way perfect though. Two tires/rim combos with the same measured width could/will have different volume and profile but it is better than what the tire has printed on the side.

Originally Posted by Mark McM

Well, not exactly. Because if 25mm tires were actually 27mm tire, then they would also be 23mm tires.

A clincher tire casing does not create a complete pressure vessel, so its inflated width depends on the rim it is mounted on. The labeled width of a tire is based on being installed on a reference rim. If you install the tire on a rim wider than the reference rim, it will inflate wider the label width, and if you install the tire on a rim narrower than the reference rim, it will inflate narrower than the label width. Currently, ETRTO says you can install a 25mm tire on a rim width from 15 mm - 23mm, although previously they said 13 mm - 17mm. A tire labeled 25mm will inflate to an actual 25mm width on a rim about 17mm wide. On a 13mm rim they will be closer to 23mm, and on a 21mm rim they will be about 27mm.

So, the answer to "how wide is a 25mm tire" is similar to the answer for "how long is a piece of string."

[Mark McM]

Originally Posted by bicycletricycle

This is a weird post Mark
Everyone knows this.
Doesn’t really mean much though.

Sorry, I read your post to fast. I thought you were complaining that the actual size didn't match the labeled size.

I guess you meant that regardless of what the label says, if a tire inflates to width X, than it acts like an X width tire, which is an entirely valid point.

[bicycletricycle]

No worries

I guess I could say pros are running 27.5mm measured width tires for clarity

Originally Posted by Mark McM

Sorry, I read your post to fast. I thought you were complaining that the actual size didn't match the labeled size.

I guess you meant that regardless of what the label says, if a tire inflates to width X, than it acts like an X width tire, which is an entirely valid point.