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Tyres reluctant to inflate

Discussion in 'Beginners' started by Ham, 4 Apr 2008.

  1. Ham

    Ham New Member

    Location:
    Lancashire
    (Posted this originally inside a thread by mistake!)

    Help! - Got delivery of me new bike (Giant SCR 2008) t'other day and am having a problem with air pressure. The rear was already half inflated and assembled - the rear wheel I put on and pumped up - problem is (using a normal pump AND a cycleair pump) they dont seem to want to inflate above half/ 2/3rds pressure i.e. put a bit a weight on 'em and they are flat! - Is it dodgy valves?, (on both!) - any ideas?
     
  2. walker

    walker New Member

    Location:
    Bromley, Kent
    Have You Unscrewed The Valve Limiter?
     
  3. Mortiroloboy

    Mortiroloboy New Member

    Have you got a track pump? if not get down to Lidl next week they are doing one for a fiver, or pop along to your LBS (support your LBS) and buy one there. Track pumps are the best way to get the correct amount of air into tyres, as Walker points out check that the valve limiters (the screwey in bits at the top of the valve) are fully open when inflating, and screwed down tight when your done, other than thay cannot really see what your problem will be, unlikely (I'd have thought) that you would have got two dodgy valves on a bike out of the shop!
     
  4. PatrickPending

    PatrickPending Veteran

    Location:
    Leicester


    for some pictures see here:-


    http://www.sheldonbrown.com/gloss_p.html#presta


    if they are open just push the middle bit in a bit to let a tiny bit of air out - this just makes sure the valve is free and not stuck
     
  5. pbar

    pbar New Member

    It would most likely be a Schrader valve won't it? These don't have limiters do they?
     
  6. domtyler

    domtyler Über Member

    Schrader valves are found on low pressure tubes like in car tyres and maybe mountain bikes, certainly not high pressure road bike tubes.
     
  7. CopperBrompton

    CopperBrompton Bicycle: a means of transport between cake-stops

    Location:
    London
    In the UK at least, almost all the bike valves I've seen are Schraders - road, mountain, trike, whatever.
     
  8. Tynan

    Tynan Veteran

    Location:
    e4
    got presta
     
  9. threefingerjoe

    threefingerjoe Über Member

    Location:
    St. Louis, MO, USA
    Use of Presta valves has nothing to do with the pressure. The Presta valve can be accomodated by a narrower rim. Schrader valves are used in heavy truck tyres (120 psi in some cases) and also in air conditioning systems which can reach much higher pressures than bike tyres.
     
  10. pbar

    pbar New Member

    Yes, that's what I thought, but started to doubt it after seeing the last couple of posts.
    I've never seen anything other than the Schrader ones.
     
  11. domtyler

    domtyler Über Member

    I stand corrected :sad:

    http://en.wikipedia.org/wiki/Schrader_valve
     
  12. BentMikey

    BentMikey Rider of Seolferwulf

    Location:
    South London
    I still see more presta than schrader valves, so I'm a bit surprised at the comments to the contrary.

    As for inflating the tyres, the pot of elbow grease is thataway ---->

    :sad:
     
  13. CopperBrompton

    CopperBrompton Bicycle: a means of transport between cake-stops

    Location:
    London
    I got a track pump as it looked preferable to elbow grease. :-)
     
  14. OP
    OP
    Ham

    Ham New Member

    Location:
    Lancashire
    Sorted!

    Thanks for the info guys - the problem was that I had not had any experience with this type (Presta) of valve before and was, indeed,, not releasing the the teeny tiny thingiemebob on the valve...we live and learn and, who knows? one day I may even be as mechanically adept as my dog!
     
  15. BentMikey

    BentMikey Rider of Seolferwulf

    Location:
    South London
    Don't worry, I'm sure we've all forgotten to undo the release at least once!!!