turbo cotton

Everything about building wheels, glueing tubs, etc.
Imaking20
Posts: 1621
Joined: Fri Nov 18, 2011 5:19 am

by Imaking20

nachetetm wrote: ↑
Sat May 26, 2018 4:56 pm
I greatly disagree with your conclusions from that video. One of the riders was two seconds faster on 28 than on 25.... on a 3:45 minute ride. On an hour ride that will be 32 seconds. We can claim it is not much for someone not racing but most of the times aero wheels give less advantage for a much bigger expense, as using a wider tire is a free upgrade. 28c is also a bit more comfortable over 3:45 minutes ride. In a three hours ride the difference will be very substantial.

The other rider found the opposite result, 25c was two seconds faster than 28c
"Greatly disagree" seems strong for two seconds... especially when it swung back the other direction. And since the testers disagree.

https://youtu.be/xPi6lvkp7qw?t=6m50s
To me the conclusions are very clear from those videos. When the road is rough, 28c are much more comfortable and much faster. There is much more to gain going wider than going aero. With smoother tarmac that may be different, but in a ride with changing tarmac, I am sure at the end it is faster the wider tire versus the narrower.
Again, pretty surprising to draw such clear - and opposing - conclusions from the people conducting the test in the video.

https://youtu.be/xPi6lvkp7qw?t=7m32s


Ever try bumping down pressure in the 25s? :D
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alcatraz
Posts: 1295
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

If you are lighter then go narrower as aero could trump rr. If you are heavier then go wider as rr could trump aero.

/a

nachetetm
Posts: 39
Joined: Fri Aug 18, 2017 8:54 pm

by nachetetm

Imaking20 wrote: ↑
Mon May 28, 2018 3:55 am
nachetetm wrote: ↑
Sat May 26, 2018 4:56 pm
I greatly disagree with your conclusions from that video. One of the riders was two seconds faster on 28 than on 25.... on a 3:45 minute ride. On an hour ride that will be 32 seconds. We can claim it is not much for someone not racing but most of the times aero wheels give less advantage for a much bigger expense, as using a wider tire is a free upgrade. 28c is also a bit more comfortable over 3:45 minutes ride. In a three hours ride the difference will be very substantial.

The other rider found the opposite result, 25c was two seconds faster than 28c
"Greatly disagree" seems strong for two seconds... especially when it swung back the other direction. And since the testers disagree.

https://youtu.be/xPi6lvkp7qw?t=6m50s
To me the conclusions are very clear from those videos. When the road is rough, 28c are much more comfortable and much faster. There is much more to gain going wider than going aero. With smoother tarmac that may be different, but in a ride with changing tarmac, I am sure at the end it is faster the wider tire versus the narrower.
Again, pretty surprising to draw such clear - and opposing - conclusions from the people conducting the test in the video.

https://youtu.be/xPi6lvkp7qw?t=7m32s


Ever try bumping down pressure in the 25s? :D
I would find complicated to bump down pressure in the 25c tires to 45psi without having problems, but you are free to test.
My conclusions just follow what Josh Poertner has been saying for years, but you are welcome to ignore them.

ichobi
Posts: 652
Joined: Thu Jan 19, 2012 11:30 pm

by ichobi

Would you reckon 26mm tires work well on 17mm internal width rim? I am considering the new forecrest that has nsw braketrack (17mm internal) to go with 26mm turbo cotton.


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nemeseri
Posts: 713
Joined: Tue Apr 07, 2015 5:40 pm

by nemeseri

Try it, but I believe that everything over 25mm on a road bike, on a paved road is all in your head (speed and comfort wise)! Except if you are close or over 100kg.

I know I will get hell for this, but I'd never mount 28mm clinchers on a road bike for road riding. I just sold an all-road focus paralane with 28mm schwalbe ones. They were huge, sluggish and very slow to accelerate. They were amazing for gravel, dirt, wet downhill sections and for roads I'd normally wouldn't ride on a road bike.

Side note: the 28mm turbos will be probably 40 grams heavier than the good ol' GP 4000s in 25mm (and those balloon up to at least 27mm, but probably to 29mm on a wide rim). All of that weight is rotational weight and I'd pay a lot of money to remove 40 grams from my rims.

Also I do believe that tire pressure has a bigger influence on ride quality than the tire itself.

guyc
Posts: 531
Joined: Thu Mar 24, 2011 9:40 am
Location: Hampshire, England
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by guyc

So you haven’t actually ridden them?

nemeseri
Posts: 713
Joined: Tue Apr 07, 2015 5:40 pm

by nemeseri

I did try the turbos for about 1300 miles. 24mm front, 26mm rear. They are super good looking, high quality tires, they were easy to mount. BUT they didn't feel anything special comparing to the vittoria corsa g+. I started to get flats after about 1000 miles like crazy (especially in wet). Given their price, riding 10k miles every year, I won't return to them.

Regarding ride quality: if somebody held a gun to my head to tell which tire I'm on, blind folded, it would be hell of a decision. Maybe it's my weight, riding style, handle bars, wheels. I have no idea. I struggle to notice ride quality differences between high end tires. Even high end conti tires feel pretty much great to me. I did notice ride quality differences between tubs and clinchers, but I'm not sure if that's just the lighter rim.

EDIT: my post was mainly about tire sizes. In general, I don't think it's a great idea to ride 25+ clincher tires on road. You can always hop on your CX or mountain bike for the rough roads. YMMV.

EDIT 2: If low CRR and being aero are very important, I'd pick probably conti supersonics, TTs over the turbos. Given they have similar or lower CRR and *probably* better aero properties than the turbos and they are much lighter.

guyc
Posts: 531
Joined: Thu Mar 24, 2011 9:40 am
Location: Hampshire, England
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by guyc

My mileage does indeed vary.

On my Bora's a 25mm GP4000's measures 27.3mm, a 28mm TC measures 27mm dead. So the stated size becomes less relevant that actual size. I can feel a significant different in comfort between the two - the former has a hard and unforgiving ride in comparison. Something like a Corsa would be far less significant compared to a TC as we're again comparing two open tubulars rather than one with a vulcanized clincher.

The roads around me are, frankly, toilet, and a 28mm makes a whole lot of sense. But then I'm on a C64 and not that into aero for the roads I'm riding.

Marin
Posts: 3062
Joined: Wed Jan 22, 2014 11:48 am
Location: Vienna Austria

by Marin

@guyc you're saying a 28mm Turbo Cottom actually comes out undersized?

guyc
Posts: 531
Joined: Thu Mar 24, 2011 9:40 am
Location: Hampshire, England
Contact:

by guyc

On a Bora yes.

But the 24mm is closer to a 23mm and the 26mm is closer to 25mm. So it’s consistent.

billendk
Posts: 19
Joined: Sun Oct 25, 2015 8:13 am

by billendk

On my hunt wheels 26mm come out at 28 mm

On my enve ses 4.5 they are thrue to size.


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CrankAddictsRich
Posts: 1258
Joined: Wed Jan 27, 2016 1:39 pm
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by CrankAddictsRich

On my Yoeleo wheels (25mm width brake track) the cotton 24's measure out to 25.5 and the 26's measure out to 27.25.
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