Vittoria Evo-CX Tubs Losing Pressure

SteK
SteK Posts: 148
edited October 2010 in Workshop
I'm getting a bit frustrated with my Vittoria Evo CX tubulars. They lose quite a lot of pressure - they'll go from 120psi to 80psi overnight.

They've got Tufo tub sealant in 'em, and I've 'belt and braced' the seal between the valve extender and the original valve body with PTFE tape. I've dunked them into the sink to look for significant leaks but the only thing I can see is what appears to be slight weeping of air from the fabric side of the tub.

I've read/heard that the latex tubes in some higher-end tubs can be prone to leaking. Is this likely to be the case here? Does anyone else have this problem with evo-cxs?

Sorry if this has been asked before. Used the search but couldn't find much...

Ste

Comments

  • softlad
    softlad Posts: 3,513
    latex can and does leak pressure over time, and mine used to lose maybe 10psi over night, but a 40psi loss sounds a bit extreme...
  • SteK
    SteK Posts: 148
    I suppose if it's going to lose any pressure it's going to need pumping up, I just find it frustrating/odd that I can't find anywhere significant where they're loosing it from.

    Also, they both lose virtually the same amount of pressure, to within 5psi (based on my track pump gauge) - it kind of rules out punctures - or it'd be a long shot for there to be two identical slow punctures...

    Guess I'll just keep on with the track pump...
  • Pokerface
    Pokerface Posts: 7,960
    It's normal - don't worry about it. There's no puncture.

    The latex tubes inside are very permeable so air leaks out quite easily. All my Vittorias do the same thing - and sealant won't help.

    My Conti tubs don't do it - but they use different tubes inside.


    Just have to get used to pumping it up before each ride.
  • SteK
    SteK Posts: 148
    Ah that's cool then, thanks for the advice.

    Maybe Continentals next time then! Or maybe I should just stop moaning and getting pumping up!
  • moonshine
    moonshine Posts: 1,021
    Am i not right in thinking tufo tyre sealant is't the right thing to use with Vitorria latex tubes?

    Vittoria use their own form of latex sealent in "pit Stop", but the problem with this is if your tyre goes completely flat over a period of time, the tibe will stick to itself and ruin the tyre.

    I thought the tufo sealant was different as someone said the tufo tubs don't have an inner tube , per say, rather the whole trye is airtight.

    I might be well of the mark here.

    not withstanding this, what you are finding is standard. they deflate with time fue to the latex inner tube. The vittoria triathlon tyres use a butyl tube to stop this being a problem, as in big races, bikes go into a park ferme style arrangement in transition areas the night before a race and no one can touch them on race day, therefore the tyres need to stay solid.
  • SteK
    SteK Posts: 148
    ooh - I'm not sure, as far as I understood it's latex carried in ammonia, I kind of assumed (I know what they say about assuming!) that it'd be ok in latex inners, but you could well be right. Urgh, I hope not though, I'm going to struggle getting it back out!!!

    I've got a can of pit-stop too but I kind of saw them as different things, I've always considered pit stop as more for road-side repairs - although I'm skeptical of the pressure it'd put into my tub so always roll with that and a couple of CO2 cans... I saw the Tufo stuff as more of a preventative measure...

    The bottle of Tufo slime does say that it's suitable for normal clincher inner tubes though? I know the Vittoria tube is latex but I'd have thought a 'normal' inner tube bears more resemblance to a traditional style tub than one of the Tufo 'innertube-less' tyres?

    *brain melts*

    Good bit of info about the triathlon tyres. Is there a downside to butyl?
  • Pokerface
    Pokerface Posts: 7,960
    SteK wrote:
    Is there a downside to butyl?


    It's heavier.