Derailier Noisy

millermilla Posts: 30
edited September 2009 in MTB beginners

I have an 08 Kona Cinder Cone with Deore LX rear mech. When going over some heavy bumps I've noticed a very loud bang from the rear of the frame which I traced to the Derailier hitting the rear drop out when in gears that makes the chain short i.e small cog at the front and back. Is my chain too long or do I need to make some sort of adjustment?



  • Anonymous
    Anonymous Posts: 79,667
    in gears that makes the chain short i.e small cog at the front and back.
    Well, there's your problem.
    You shouldn't do that.
  • piker
    piker Posts: 353
    You shouldnt use that sort of gear combination puts alot of strain on the chain.Small ring at front only use top halve of cassette,large ring at front bottom half of cassette,middle ring at front all rear cassette.
  • OK sorry bit of a typo it happens when I'm using the middle front cog and small rear cogs. I can understand using the front large cog and rear large cogs when doing some downhill but when riding bumpy flat trails I tend to be using the middle crank cog and middle to low rear cogs and its still hits the rear dropout.
  • Anonymous
    Anonymous Posts: 79,667
    using the front large cog and rear large cogs
    You shouldn't be doing that, either.
  • nicklouse
    nicklouse Posts: 50,675
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Thanks for the link nicklouse, I do try avoiding those gears as suggested however as I said in my second post I meant middle crank ring and small rear cogs which shouldn't be a problem? I've just looked and in that gear combo, middle crank, small rear cog the derailier is only about 3mm from hitting the frame so if you go over any bumps it bangs like a hammer. It's almost as if it needs a stop adjustment to stop it moving round too far.

    Thanks for all the advice guys.
  • guilliano
    guilliano Posts: 5,495
    There is a screw on the mech which pushes the jockey wheels away from the cassette, which in turn moves the mech further from the frame. Try adjusting that a bit
  • A very good place to start learning how your bike works is here:

    Still an essential source of info for me after all these years :wink: