I just got a set of Zipp 606’s with tubular tires. When I pump them up to 140 psi, they do not leak right away, but the next day they are 120 and after a few days they are down to 40. Both tires do this. Is this a slow leak? Will I flat in a race because of this? What should I do about it? thanks.
What type of tires… I just experienced this with a TUFO. Instead of sending it back I put some TUFO sealent and it seems to fix the problem. 1 out of 3 tires purchased had this issue.
They’re probably Victoria Corsa CX or other tubulars with a latex inner tube, they lose air faster than butyl tubes.
I’ve ridden tubulars for 20 years… even the best tubular doesn’t loose that much presure in 48 hours.
Granted, tubulars will loose much more presure, quicker then any clincher setup that I’ve ridden.
Valve extender problem?
Did you ever ride Corsa CX? Apparently not… You should, it’s a great tubular, just a pain to have to pump them before every ride.
This slow leaking is standard for any tires with latex tubes (I’m assuming that you are using a tubular with latex tube such as the Zipp, Clement, Vittoria…). The latex is so very thin, that the air molecules can slowly escape through the material over time, but over the relatively short periods of time we are on our bikes, the effect is non-existant. ~20psi in 20-24 hour period is normal and expected. The upside of latex tubes is that they reduce rolling resistance by a statistically significant margin, and are more puncture resistant than butyl tubes due to their much higher elongation characteristics.
Tufo tubulars use butyl liners molded into the tubes and should not leak overnight, so that may be a sign of another problem.
I’m not sure what kind of tires they are - I will have to check when I get home. I had Zipp 404 tubulars last year, and they kept their air for weeks, but it was a royal pain to get air into the tires. It is really easy to get air into the new tires, but they are much softer the next day. I remember the guy at the bike store using a set of pliers on the valve extender of the old 404’s? Does something need to be tightened?
I have had loads of Vittoria CX tubs that do the same thing. Not a problem.
Tubulars with latex inner tubes lose air at a frighteningly fast rate.
He knows that, he’s been riding tubulars for 20 years…
I’m with Paulo. My Vittorias do the same thing.
But he said he never saw this before. I’ve only been using them for a few years and I have seen this before. N=1 for each of us.
When I 1st got my Tufo’s they did the same thing. I tightened the valve and didn’t have the problem with the rapid pressure loss. Your extenders they may need the same treatment.
Your telling me that you lose 80-90 psi in 48 hours… I doubt that.
My experience is that I’ll lose at most 40 PSI in 48 hours, then much slower after that point.
If you use valve extenders and do not screw the valve down, they can leak thru there as well. I have had a couple tubies leak pretty fast thru the years. I just figured it was a pretty thin tube or a slow leak at the valve stem.
Your telling me that you lose 80-90 psi in 48 hours… I doubt that.
Hmm. I don’t remember saying that, though it’s entirely possible that I lose that much. I’m not sure where you got those numbers from. I guess out of thin air. Jon said he loses 20 the 1st day and after a few days they are down to 40. Exactly my experience.
I’m not sure how much I lose in 48 hours, but it’s a whole lot. I just pumped my tire up to 140 and I’ll see how much I lose in 24, 48, and 72 hours.
Related question, just got my first tubulars. Is it OK to let the bike sit with 2 flat tires, or should I put air in em every few days even if I’m not riding that often?
Just mounted a new Vittoria CX T.T. Pro on Saturday and pumped it up to 120 psi. It’s probably at 40 or 50 psi, now.
I’m not sure how much I lose in 48 hours, but it’s a whole lot. I just pumped my tire up to 140 and I’ll see how much I lose in 24, 48, and 72 hours.
48 hours later I have about 55 psi. That’s an 85 psi loss.
Vittoria Corsa Evo-CX