10 speed chainring, 9 speed cassette\chain, problem?

V5ade
V5ade Posts: 192
edited March 2010 in Workshop
The big chainring on my Boardman Team (hybrid commuter thing with Truvativ Elita chainset) failed a few weeks ago. The ring ripped apart as I pulled away in top gear.
My lbs replaced the chainring for me, however since than the chain jumps off the big chain ring when under serious load. The lbs have replaced the chain and cassette even though neither looked worn, but it's still doing jumping off.
While cleaning it yesterday I noticed that the new chain ring is 10 speed, when the rest of the drive train is 9 speed. Could this be the problem?
Sorry for the long post, but I'm going mad as I have top stop to pop the chain back on about once per mile!
Somewhere in the Surrey Hills :-)

Comments

  • desweller
    desweller Posts: 5,175
    No. Chainrings can be used with any back block/chain combination. Is your front mech correctly set up?
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  • V5ade
    V5ade Posts: 192
    The bike shop have had a few goes at setting up the front mech as they thought the same thing. They're convinced it's all fine and helpfully suggested that I slow down :roll:
    It seems to shift up\down correctly, the chain comes off even if you haven't shifted for a while.
    Somewhere in the Surrey Hills :-)
  • crankycrank
    crankycrank Posts: 1,830
    Try a different bike shop. Drive trains are not rocket science. It could possibly be some type of unusual flaw in the mech/chain or setup but there are only a few possible problems that can exist to cause your chain to fall off. Any competent mechanic should be able to fix this and it's possible that your LBS replaced the chain and cassette unnecessarily. Better yet, learn to do it yourself and save grief, time and ££'s.
  • V5ade
    V5ade Posts: 192
    Guys, thanks for the help :D
    I'm going to take it to another bike shop and see what they say (I'm also going to gt myself a cycle repair book and a workshop stand so I can try to learn about this myself).
    Somewhere in the Surrey Hills :-)
  • crankycrank
    crankycrank Posts: 1,830
    V5ade wrote:
    Guys, thanks for the help :D
    I'm going to take it to another bike shop and see what they say (I'm also going to gt myself a cycle repair book and a workshop stand so I can try to learn about this myself).
    Good for you! At first many of the parts on a bike look complicated and mysterious but once you understand how everything works you may be surprised at how simple (but brilliant) the pieces are. A good repair book with exploded diagrams of each part should help quite a bit.