Bora WTO

Everything about building wheels, glueing tubs, etc.
bobones
Posts: 136
Joined: Mon Aug 12, 2013 11:19 am

by bobones

Here's a few of mine.
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jgpallero
Posts: 42
Joined: Fri Sep 21, 2018 7:13 pm

by jgpallero

Thank you for the photos. I can see the measured width when inflated is in Vittoria a little bit more than in Continental, which is congruent with the data provided by https://www.bicyclerollingresistance.com

by Weenie


ParisCarbon
Posts: 1604
Joined: Mon Feb 05, 2007 5:39 am
Location: Winnipeg Canada

by ParisCarbon

jgpallero wrote:
Fri Sep 04, 2020 10:32 pm
Hello,

Anyone riding Bora WTO with 23 mm tyres? Although the inner rim measure is 19 mm Campagnolo says that the WTOs are designed also for 23 mm tyres. Also, the exterior rim measure of 26.5 mm makes the rim wider than the tyre (23 mm at 8 bar actually produces a measure of about 24 mm in Continental GP 5000), which is optimal from the aerodynamic point of view. Is it safe to use a 8 bar pressure with carbon Boras?

Finally, if someone uses 23 mm tyres with WTOs, could please upload some photos?
Ive got SWorks Turbo Cotton 24mm on mine, and they are awesome!

neeb
Posts: 724
Joined: Tue Jan 27, 2009 8:19 pm

by neeb

bobones wrote:
Sat Sep 05, 2020 8:21 pm
I've got a few hundred miles on my WTOs with 23 mm Corsa Speeds. No problem and they look good. I'll post a photo and measure them tomorrow, but I run them at only 5.5 bar.
Wondering if there's a consensus on the best pressure to run 23mm clincher tyres at on WTO rims. I'm about 63kg and used to running 23mm tyres at about 95/90 psi on my Reynolds Aero, but they only have a 16mm internal width. Wondering how low I could go on the 19mm internal WTOs without risking pinch flats on potholes..

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Mockenrue
Posts: 533
Joined: Mon Aug 20, 2012 10:32 am
Location: Untied Kingdom

by Mockenrue

Here's mine:

Image

bobones
Posts: 136
Joined: Mon Aug 12, 2013 11:19 am

by bobones

neeb wrote:
Mon Sep 07, 2020 3:42 pm
bobones wrote:
Sat Sep 05, 2020 8:21 pm
I've got a few hundred miles on my WTOs with 23 mm Corsa Speeds. No problem and they look good. I'll post a photo and measure them tomorrow, but I run them at only 5.5 bar.
Wondering if there's a consensus on the best pressure to run 23mm clincher tyres at on WTO rims. I'm about 63kg and used to running 23mm tyres at about 95/90 psi on my Reynolds Aero, but they only have a 16mm internal width. Wondering how low I could go on the 19mm internal WTOs without risking pinch flats on potholes..
I'm running tubeless so don't really worry about pinch flats. I'm around 72kg and 5-6 bar is plenty for me.

neeb
Posts: 724
Joined: Tue Jan 27, 2009 8:19 pm

by neeb

bobones wrote:
Mon Sep 07, 2020 11:00 pm
neeb wrote:
Mon Sep 07, 2020 3:42 pm
bobones wrote:
Sat Sep 05, 2020 8:21 pm
I've got a few hundred miles on my WTOs with 23 mm Corsa Speeds. No problem and they look good. I'll post a photo and measure them tomorrow, but I run them at only 5.5 bar.
Wondering if there's a consensus on the best pressure to run 23mm clincher tyres at on WTO rims. I'm about 63kg and used to running 23mm tyres at about 95/90 psi on my Reynolds Aero, but they only have a 16mm internal width. Wondering how low I could go on the 19mm internal WTOs without risking pinch flats on potholes..
I'm running tubeless so don't really worry about pinch flats. I'm around 72kg and 5-6 bar is plenty for me.
I suspect even with tubes though it's possible to go lower than where I'm at currently with 19mm internal. The 23mm tyres measure 25mm, so I suppose one approach would be to pressure them as if they were 25mm for my weight?

jgpallero
Posts: 42
Joined: Fri Sep 21, 2018 7:13 pm

by jgpallero

Nobody uses pressures of about 8 bar with carbon rims and 23 mm tyres? Is it safe in Boras?

neeb
Posts: 724
Joined: Tue Jan 27, 2009 8:19 pm

by neeb

jgpallero wrote:
Tue Sep 08, 2020 8:55 am
Nobody uses pressures of about 8 bar with carbon rims and 23 mm tyres? Is it safe in Boras?
Probably safe (?), but curious why you would want to run them that high? I noticed that the conti clinchers were very solidly attached to the rim when installed - pretty difficult to get off actually, I can't imagine them easily blowing off even at very high pressures.

I'm just wondering if I can get away with going from 6 / 6.5 bar to 5.5 / 6 bar front and rear with 23mm clinchers..

jgpallero
Posts: 42
Joined: Fri Sep 21, 2018 7:13 pm

by jgpallero

neeb wrote:
Tue Sep 08, 2020 9:59 am
jgpallero wrote:
Tue Sep 08, 2020 8:55 am
Nobody uses pressures of about 8 bar with carbon rims and 23 mm tyres? Is it safe in Boras?
Probably safe (?), but curious why you would want to run them that high? I noticed that the conti clinchers were very solidly attached to the rim when installed - pretty difficult to get off actually, I can't imagine them easily blowing off even at very high pressures.

I'm just wondering if I can get away with going from 6 / 6.5 bar to 5.5 / 6 bar front and rear with 23mm clinchers..
I think it is only a personal habit. All my life I rode at 8 bar with 23 mm tyres (my weight is only 59 kg, but I feel comfortable at 8 bar). My question about if it is safe is not motivated by the possibility of the tyres get off, but by this high pressure can be supported by a carbon rim. I remember when the first carbon rims come to the market that they do not support such high pressures

neeb
Posts: 724
Joined: Tue Jan 27, 2009 8:19 pm

by neeb

jgpallero wrote:
Tue Sep 08, 2020 10:31 am
I think it is only a personal habit. All my life I rode at 8 bar with 23 mm tyres (my weight is only 59 kg, but I feel comfortable at 8 bar). My question about if it is safe is not motivated by the possibility of the tyres get off, but by this high pressure can be supported by a carbon rim. I remember when the first carbon rims come to the market that they do not support such high pressures
Delving into the technical instructions for the wheels, there is no specified maximum pressure, only the stipulation that you shouldn't exceed the tyre manufacturer's maximum recommended pressure:
Never exceed the maximum inflation pressure recommended by the tire manufacturer or for the cross section of the clincher tire you are using. Excessive tire pressure reduces grip on the road and increases the risk that the tire will unexpectedly burst.
I suppose if you were being ultra-cautious you could read "cross section" as "measured width" rather than specified width. So if a 23mm tyre measures 25mm when fitted on the 19mm rim, perhaps it would be good not to exceed the maximum pressure recommended by the tyre manufacturer for their equivalent 25mm tyre. This would seem sensible to me, if perhaps unnecessary.

I think Campy wheels in general are very solidly built - pretty sure they will be able to take 8 bar, especially for someone as light as yourself.. If it's any help, I inflated mine to nearly 10 bar briefly just to make sure the bead was seated and they didn't explode.. :D

jgpallero
Posts: 42
Joined: Fri Sep 21, 2018 7:13 pm

by jgpallero

Thank you for tour answer.

Wow, 10 bar. With the Continental?

neeb
Posts: 724
Joined: Tue Jan 27, 2009 8:19 pm

by neeb

jgpallero wrote:
Tue Sep 08, 2020 12:45 pm
Wow, 10 bar. With the Continental?
Yes - just for a few seconds though! I usually do this when I install clinchers, especially if they are new. I over-inflate just to make sure the bead is in place and the tube isn't trapped anywhere. Then I deflate and reinflate to the riding pressure.

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pdlpsher1
Posts: 2971
Joined: Thu Jul 19, 2012 6:09 pm
Location: CO

by pdlpsher1

jgpallero

The stress of a tire on the rim is dependent on pressure and the inner surface area of the tire. This is why you can run narrow tires with high pressure without damaging the rim. Let's say you run 8 bars on a 23mm tire. If you instead use a larger tire with twice the internal surface area you will exert the same amount of force on the rim at only 4 bars.

So yes you can run 8 bars on a 23mm tire. If you run the same pressure on a 32mm tire you risk damaging the rim.

by Weenie


zander
Posts: 31
Joined: Mon Jun 09, 2014 1:18 pm

by zander

My current wheels are RAR Svelt32. Those are quite old and light and I wouldn't need "better" but flange of the rear hub broke :( Repairing is quite expensive and I'm thinking to buy new set. I'm living very flat area and the wind is not problem to me. So it could be WTO 60 but how does it go with my old Nago?

Last summer when I still had Tri-bike I tried Zipp 404 & 808. 404 doesn't look very bad to me.
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