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Keep on breaking rear mechs + hangers!

365punter365punter Posts: 39
edited February 2009 in MTB workshop & tech
Is it just me that has serious problems with rear mechs getting caught in the spokes?

I've broken 4 rear mechs (and hangers) in 18 months. About 2 of them were the direct result of hitting them against rocks/trees but the last two have just jumped into the spokes by themselves!

My bike is used for commuting so gets used in all weathers and I hardly ever use a low gear on the rear cassette (which keeps the mech away from the spoke), but on the trails I use all my gears.
Could the problem be something as simple as the mechs needing to be looked after more? After setting up my gears I never feel the need to adjust them again.

My back wheel is also slightly buckled - sounds obvious but i suppose that's another reason why I'm losing rear mechs all the time!

I've almost spent the equivalent of my bike's brand-new value (£270) on mechs, rear hangers and chains! If anyone has any good ideas on how to stop this happening then I'd love to hear from you. Thanks!

Bike specs: 2007 Mongoose Tyax Elite, with 9spd drivetrain (most recent rear mech was a Shimano rapid-rise LX jobby)

Posts

  • nicklousenicklouse Posts: 81,520 Lives Here
    well for one sort the wheel out and if your mech starts clicking look at it.
    And maybe revise the way you set up your gears.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • It sounds like the mech gets knocked regularly, maybe review how you store the bike and check it regularly? mech hangers are soft and designed to break, their job is to save the frame.

    Another thing you may be able to do is fit a cassette spacer behind the cassette to bring it slightly further away from the spokes giving more scope for knocks. but this will depend on whether you can still get a lockring on and use the top gear without the chain hitting the frame.
  • MrChuckMrChuck Posts: 1,663
    Sounds a bit patronising but they don't just jump into the spokes by themselves! Obvious place to start is the limit screw- if this is set properly the mech should never be able to move far enough over to get near the spokes.

    Cables do stretch so your gears will go out over time if left to themselves, although this shouldn't make much difference in this case.
  • supersonicsupersonic Posts: 82,708 Lives Here
    Can always fit a spoke saver disc behind the cassette. Though it does sound like the L stop needs setting up better.
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