Hi guys,

now that i finally am on my new tubies, i want to thank you all for advice and knowledge.
I was quite curious when i started my new wheel-project with the Planet X 82mm wheels
and contis GP4000 SR but reading this Thread up und down made it, well not easy but predictable to some extent
my steps were:
-prestretch tire on the rim for 3 days
-i put 3 layers on the rim, each cured 24h
-i put 1 layer on the tire cured over 24h
and then the "mounting" layer on the tire as well and put them on

i can't compare the contis to any other tire, but they are really well made
and easy to center when initially putting them on...
of course i did use Mastik...

the ride itself is much more "plush" than i expected with ~8.5bar (i run my clinchers with ~6bar on a wide rim)
however as before, can't compare... first carbon, first deep rim, first tubular

Just one question, a bit OT...do all those carbon rims scream like hell when on the brakes?
ok...with 82mm they've got a really big body to sing.
I'm using the planet x carbon pads and when breaking hard and keeping the brakes closed when eg. waiting
for traffic to pass, the pads literally melt on to the rim
any advice on pad choice?

so, thanks again and happy trails

Tubular advice needed !!!

Had my tubulars on for two weeks, been on a few rides, no problems to report on ride or operation.

Pumped up tyres last night as they were getting quite flat, pumped to about 130 - 135 psi.

This morning, front still hard, rear flat !!!

Where should I go looking first, could it be a slow leak on the valve ?

I have not checked the tyre yet as I had to leave for work but was wondering if it would be best to check the valve before I remove the tyre to go searching for the cause of the problem.

I'm going to assume that if there is no obvious signs of a puncture to the tyre then it must be the valve ?

Really don't mind if I have to remove the tubular as I think it will be good practise for when it happens on the road. Far better to remove and replace a tyre at home for the first time rather than find out miles from home how not to do it !!!

Would also not mind trying to repair the tyre but don't think it is a puncture that is causing the slow leak.

Any advice guys ???

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Enigma Echo

Dip the tire in water and look for bubbles as the location of the leak.

Is there any chance to seal inner tube, without unsewing?

Try toeing in the pads, that should fix the squealing. If Planet X is still usuing Gigantex rims, SS yellows or Reynolds blue pads both work well.

@wetpaint: thanks for your advice...will try that and going to order some new pads
pads wear like icecream in the sun

@NoMütze, I personally prefer natural cork pads to the synthetic options currently available (I have been running the 'blue' Shimano carbon pads and they are pretty good, but are not commercially available). The cork pads do not seem to squeal as badly. The Zipp synthetic pads are the worst! (for squealling)

@Simonhi, the first place to check is the valve core. I like to take a couple of turns of plumber's teflon tape around the threads of the valve core before making sure it is firmly tightened. This prevents any leaking that might occur from the valve. If you are running latex tubulars, air loss is normal and you should expect to pump tires before every ride. As an aside, there are very few instances where you would want to ride a tubular with 135 psi in it. I prefer to run 100/110 or 112 front/rear (less in-the-wet).

Cheers Geoff, turned out it was the valve core, I put a little weak thread locker on it to prevent twisting out again when I remove the pump. The valve extender has a few wraps on Teflon tape on the thread.

Normally run about 110 - 115 too, only pump to 135 to save time between pumping, is this a bad thing? I suppose it no great hassle to pump to 100 ish and then pump to correct pressure when I go out.

Cheers for all the advice, it is great fully received and will probably save me a few headaches along the way.

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Enigma Echo

Hi,



Assuming a latex inner tube, it's not worth the trouble as the higher the pressure the faster air will leak away anyhow.

Ciao,

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Being a snob is an expensive hobby.

Makes sense I suppose,

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Enigma Echo

After less than 500 miles, my rear and front Conti 4k tubular failed. I am looking for replacement and considering for 25mm tire. I have 2011 Cannondale Supersix with Bontrager Carbon Aero (20x43mm). Is there a way to measure if the tire will fit the frame ? any comment on the durability of 22mm vs 25mm of the same brand ? I am thinking of getting Ultremo HT or veloflex roubaix or FMB paris roubaix cotton, but I have been reading that the last 2 need to be aged to get the best out of them; therefore Ultremo HT is my first choice and also is cheaper.

Also since the rim width is only 20mm, would it be more dangerous to fit bigger tire into the rim such as if it is not glued perfectly, it will roll off the rim easier ?

Thanks for the advice.

Why you just don't repair you Conti tyre? Or, you tore it appart, or something like that?

@Jarade

If you see one of the pictures both tires have really nice cuts along their edges. The cuts have almost exactly the same distance from the edges of the tires. The cuts are about 1/4 of the tire circumference, and they seems to be growing longer and longer as I used it. In the second picture, you can see the rubber seems to be peeling off the tire sidewall to expose the thread. This happens on both tires also. Finally after I finished riding last Saturday luckily, the tire blow itself at its sidewall.
The only cause of the cuts I can think of is if were to run into cracks on road on both tire. As for sidewall failure, I have no idea.

Good evening, I'm slowly working my way through this great thread before gluing my Veloflex Sprinters on to my Hyperons. After reading this I find myself wondering if base tape scraping is for all Veloflexes or just the Record. Thanks.

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So long, and thanks for all the fish.

Perhaps I'll finish reading all of this thread before I ask any more questions. Further reading has answered my question and I see that a previous question I had about carbon specific glue was already addressed. Great thread and thanks for all the good advice FD and Geoff.

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So long, and thanks for all the fish.