25mm tubulars.....stopped in my tracks.

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Steve_W
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by Steve_W

Okay, after all the hype opted for a 25mm tyre (conti comp)
After the painful process of fitting, ready to roll. Mmm, hadn't given it a second thought regarding fork clearance....about 1mm max, maybe less, from the fork bridge (centre) fork is a look hsc7 (look 695)
Now, what are my options, I've come up with these.
1/ 22mm conti comp. (why don't they do a 23!!!)
2/ 23mm veloflex Carbon
3/ 25mm vittoria corsa cx111 (hoping the tyre height is less the the comps)
I'd seen some 25mm comps fitted to a set of lightweights before, however once I'd mounted mine they looked huge!!!

Thoughts appreciated, Steve

964Cup
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by 964Cup

22mm Conti comps work well for me (R5Ca, Enve 45s); one issue with tyre height on tubs is that you are likely to have a "bump" where the valve sits, so having 1mm of clearance elsewhere won't be enough.

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Steve_W
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by Steve_W

Right, I'm a believer in honesty.....id taped the tubs on with tufo tape which is quite thick. I've removed the tape and refitted without.
The difference really is quite an amount! It's surprised me how much.
I've now 2-3 mm clearance, so I'm guessing it's out with the glue stick.
Unless anyone wants to advise an alternative?

Steve

Steve_W
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by Steve_W

964Cup wrote:22mm Conti comps work well for me (R5Ca, Enve 45s); one issue with tyre height on tubs is that you are likely to have a "bump" where the valve sits, so having 1mm of clearance elsewhere won't be enough.

When I'd measured the >1mm I'd taken from the anomaly of the "annoying bump" in to consideration.
I'd put an old 22mm comp on before the 25 and they looked lost, really thin.

Steve

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MJB
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by MJB

Glue up the 25mm. It is not life or death if you have to remove it after.

You will enjoy the ride of low pressure 25mm tubulars.

Your other options :-

1) As lovely as your Look is if it's not going to fit sensible tyres..................

or

2) N + 1

bm0p700f
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by bm0p700f

you should always glue anyway.

veloflex arenberg comes in 24mm I think.

Steve_W
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by Steve_W

I've opted for glue, I'm really surprised as to how much height difference it made using tape.

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Calnago
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by Calnago

There are no 24mm Veloflex tubulars currently. Arrenbergs have always been 25mm. The "older" Roubaixs were 24mm, as the older Carbons were 22mm. But now the Roubaixs are 25mm and the Carbons are 23mm. The Current Roubaix is the exact same tire as the Arrenberg but with tan sidewalls.
You mention Lightweights, are those the rims you are using? They are a very narrow rim and a 25mm tubular will not fit so great on them. Because of the narrowness, a 25mm tubular cannot really "bed in" properly as the smaller radius of the rim bed will tend to squeeze the tire upward a bit, like a push-up bra. I had this exact scenario with the pre 2015 Boras and 25mm tubulars. I could run them but clearance under the fork was minimal and I would experience a lot of "chatter" as fine road debris got thrown threw there. With the new slightly wider Boras the same tire is able to sit better and lower in the rim bed and gives me just that extra bit of clearance I needed. No more chatter.
With clinchers, going to a wider rim (within reason), you experience the opposite problem in that the the same size clincher will sit higher on a wider rim than a narrower rim, all else being equal.
And yes, use a couple thin layers of glue on the rim versus thick tape to squeeze out every bit of clearance you can get.
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Steve_W
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by Steve_W

Thanks calnago.
Yes the wheels are the lightweight melienstein, I've seen a few sets now sporting 25mm comps.....i had heard carbonsports advised against the use of 25mm on the earlier generation standards, however they quote on their site 22-25 tyre advised.
I'll see how it go's

Steve

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Calnago
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by Calnago

I would say the main reason for including the 25's in their site now, versus their previous advice, is simply because so many people want to run 25's. They will work, but it's not ideal. I suspect with the 25's on those rims, with the brakes properly adjusted, even when you open up the wheel release on the brake caliper, there will still be a bit of "squeezing" to get the tire out between the brake pads simply due to the differential of the rim width (~20mm) and the tire width (~25mm). That's kind of minor annoyance.


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Steve_W
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by Steve_W

I'd thought of the brake issue, it's boarder line.....with the caliper open it'll just squeeze in. Any tighter you'd have to adjust the barrel screw. (If that's what it's called)

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Kayrehn
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by Kayrehn

964Cup wrote:22mm Conti comps work well for me (R5Ca, Enve 45s); one issue with tyre height on tubs is that you are likely to have a "bump" where the valve sits, so having 1mm of clearance elsewhere won't be enough.

After fitting on the tub upon gluing, I inflate it halfway, use 2 zip ties on either side of the valve and make it tight, then inflate it further. It makes the valve area glue on nice and flat on the wheel. Don't think it'll work with tape though.

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Calnago
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by Calnago

I think part of the problem with the valve "hump" scenario is that people sometimes are a little lax in their initial stretching of the tube from the very start of the mounting process. I try to sort of push the valve down as hard as I can as soon as I start the mounting process, while pulling both sides of the tire out to the sides as hard as I can before starting to let the tire follow the rim around to the other side. Think of how tight the side opposite the valve is when mounting that last section of tire. I try to emulate that on the valve side when first starting and have never had a problem with a valve hump using any of the Veloflex tires or Conti Comps 22mm or 25mm. I don't mind Conti Comps at all, and prefer them for winter, not so much for improved puncture protection (I'm not sure I notice a difference) but I do think their compound is superb in wet cold weather like we get a lot of where I live. They just seem to have better traction all round in the wet. But I'll still carry a veloflex tubular as a spare because the last thing I want to do is to have to mount a conti tubular in the wild when it's wet and cold and my fingers don't want to move.
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LionelB
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by LionelB

Zero issue with Roubaix 25mm and LW here.

964Cup
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by 964Cup

Calnago wrote:I think part of the problem with the valve "hump" scenario is that people sometimes are a little lax in their initial stretching of the tube from the very start of the mounting process. I try to sort of push the valve down as hard as I can as soon as I start the mounting process, while pulling both sides of the tire out to the sides as hard as I can before starting to let the tire follow the rim around to the other side. Think of how tight the side opposite the valve is when mounting that last section of tire. I try to emulate that on the valve side when first starting and have never had a problem with a valve hump using any of the Veloflex tires or Conti Comps 22mm or 25mm. I don't mind Conti Comps at all, and prefer them for winter, not so much for improved puncture protection (I'm not sure I notice a difference) but I do think their compound is superb in wet cold weather like we get a lot of where I live. They just seem to have better traction all round in the wet. But I'll still carry a veloflex tubular as a spare because the last thing I want to do is to have to mount a conti tubular in the wild when it's wet and cold and my fingers don't want to move.

I try to do the same (and I pre-stretch my tubs by dry-mounting them on an old rim). I find you just can't get the valve seated well enough using tape, and I really can't be bothered with glue. I do find the "annoying bump" rides itself away, by and large, presumably as my weight on the wheel pushes down on the valve area.

On another note, I don't think Conti Comps are much for puncture resistance, compared say to Challenge Stradas or Vittoria Paves, but I agree about the wet-weather grip and they're certainly a lot tougher than Schwalbe Ones or Vittoria Corsas IME. I suppose if you want a broadly puncture-proof tub it's the Conti Sprinter Gatorskin, but you do need fairly smooth roads for those to be bearable.

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