Schwalbe SV20 inners, BOTH blew out within 5 mins!!!

adamdavi3s
adamdavi3s Posts: 280
edited May 2012 in Workshop
Hi All,

I fitted Schwalbe SV20 to my road build and within 5 mins of being used, BOTH blew out.... and I mean gunshot loud blew out!

I've NEVER had a blowout before so can't imagine how I installed them wrong, the cheap conties I fitted to replace them performed flawlessly...

Prior to even using these I had to send one back due to a dodgy valve, I'd just expected better from a £9 innertube!!

Are they just crap or is this something I've done wrong somehow?

Comments

  • ride_whenever
    ride_whenever Posts: 13,279
    You've almost certainly pinched them during fitting. Such very thin tubes are very delicate until fitted.

    If these were in old tyres it could possibly be detritus that wouldn't touch a thicker tube but easily defeat the thinner 20's.

    I've not had any issues with the schwalbe lightweight tubes personally, even in 20mm pro3
  • adamdavi3s
    adamdavi3s Posts: 280
    Hmm I did take a LOT of care in installing them.
    Brand new RS80's and brand new ultremo R1's so hopefully its not anything to do with those
  • AndyOgy
    AndyOgy Posts: 579
    Check the rim tape. If you've got plastic or a rubber band type thing, remove it and get some Velox cloth rim tape.

    Also, what ride_whenever said.
  • Pokerface
    Pokerface Posts: 7,960
    Why would you pay £9 for innertubes? :shock:
  • adamdavi3s
    adamdavi3s Posts: 280
    It was a new build so I was just going for everything as light as possible!
    Needless to say after that failed little experiment I'll take the 100g hit and stick with my good old £2.50 contis!!!!
  • giant_man
    giant_man Posts: 6,878
    I use SV15 Schwalbe and never had any problems so must be the way you're fitting them.
  • balthazar
    balthazar Posts: 1,565
    There is no kind of inner tube failure that can result in an explosive blow-out. That is always a clinching failure, which allowed the inner tube to escape the tyre. Any other tube would have done the same.

    The usual cause of a clinching failure is inner tube trapped between the tyre bead and the rim. It's a little easier to do (and not notice) with thinner tubes, but otherwise you should take care to seat the tyre bead very carefully, as your tubes are not to blame.
  • adamdavi3s
    adamdavi3s Posts: 280
    Yeah I guess I must have fitted them incorrectly. it just surprised me that they both gave out having never had a pinch flat (but plenty of glass / thorn based flats) in the last 5 years, even using the exact same tyre and wheel combination!
    I wondered if they were notorious for it.

    Ahh well, I'm happy with my trusty continentals at 1/4 the price so its no big deal!
  • ADIHEAD
    ADIHEAD Posts: 575
    If you want a light set of tubes, I've had my Michelin Latex tubes in my best set of wheels for over a year now :D 3 sets of tyres, same tubes. Admittedly I chuck tyres as soon as they look worn but have seen some sizeable cuts in the tyres and no p&^$es :)
  • white91
    white91 Posts: 431
    I have had the exact same thing happen! One blew out before I got on the bike, and other blew out whilst on a ride!

    I was very careful fitting, and also fitted brand new Ultremo ZXs. I think these are simply too light? I will stick with Continentals, as a blow out is scary.
  • sungod
    sungod Posts: 16,863
    light tubes are much easier to trap between bead and rim than normal weight ones, after which it's just a matter of time before the bang

    inflate the tube until it is firm (but not bulging!), then fit it

    doing it this way is far less likely to result in the tube being caught
    my bike - faster than god's and twice as shiny