Tubular Woes

woody1545
woody1545 Posts: 322
edited July 2014 in Workshop
Hi,

I've recently acquired some Corsa CX tubs on Planet X CT45 wheels. Used them for a Triathlon and they were fine.

Used them today and the front blew on the first lap, then the back blew shortly after!

Thing is, although I could hear the air rushing out at the time and they went flat quickly, they now seem to hold pressure?

Any thoughts?

Comments

  • pippi_langsamer-2
    pippi_langsamer-2 Posts: 1,470
    Sounds like the previous owner filled them with sealant?
  • racingcondor
    racingcondor Posts: 1,434
    You didn't unscrew the valves last time you pumped them up did you? On Vittoria's the valve cores are removable but so is the entire valve (presumably so you can fit long ones in deep carbon rims).

    Last week my rear tyre was losing pressure twice as fast as the front, couple of days later the valve was spinning freely. Screwed it back up and all good.
  • jgsi
    jgsi Posts: 5,062
    racingcondor wrote:
    You didn't unscrew the valves last time you pumped them up did you? On Vittoria's the valve cores are removable but so is the entire valve (presumably so you can fit long ones in deep carbon rims).

    Last week my rear tyre was losing pressure twice as fast as the front, couple of days later the valve was spinning freely. Screwed it back up and all good.

    I think the red anodized Vittoria valves just unscrew from the base and then only by hand and a nip up with the supplied plastic tool.. I maybe wrong.
    My rear Pave (punctured) has quite a mixture in it to prolong active life... it's managed to stay up 3 races now.
    downside it weighs 150 grams more than it used to!
  • woody1545
    woody1545 Posts: 322
    Thanks for your replies.

    They're actually new tyres and wheels. However, the guy in my LBS who fitted the tubs wasn't overly familiar with them and sprayed sealant in them because he was concerned by how quickly they lost pressure. I've since been informed by you nice people that this is normal for tubs with latex tubes.

    I'll double check the valves. It did sound like the puncture was in that area.
  • sungod
    sungod Posts: 17,350
    it's not a great idea to put sealant in decent tubs unless you're really desperate to try and avoid a puncture, i usually only do it once a tub is fairly worn and gets a puncture, with a newish one i'd rather remove and patch it

    now that sealant is in there try to always keep them at least slightly inflated, otherwise there's a risk that the inner tube will get stuck to itself and then tear when re-inflated
    my bike - faster than god's and twice as shiny
  • herzog
    herzog Posts: 197
    woody1545 wrote:
    ...However, the guy in my LBS who fitted the tubs wasn't overly familiar with them and sprayed sealant in them because he was concerned by how quickly they lost pressure...quote]

    Ex-Halfords employee?
  • Iamnot Wiggins
    Iamnot Wiggins Posts: 685
    Are you running deep wheels? May be an issue with the valve extenders.
  • racingcondor
    racingcondor Posts: 1,434
    JGSI wrote:
    I think the red anodized Vittoria valves just unscrew from the base and then only by hand and a nip up with the supplied plastic tool.. I maybe wrong.

    I haven't tried taking out just the valve so you may be right. Did manage to almost unscrew one taking off a Lezyne track pump though (the type that screw to the valve) so it's worth checking that they're tightly screwed on.

    OP - You can expect to lose 20-30 psi a day from Vittoria tubs, the latex tubes leak a lot of air.

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