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Rear Mech Issues

Mendip rouleurMendip rouleur Posts: 163
edited October 2009 in Workshop
My chain keeps jumping between the largest and second largest cogs on my cassette when I'm in my bottom gears. Usually when I'm about to go up a really steep hill!

Does any one know the cause of this issue and how to sort it out quickly?

Thanks
“I ride my bicycle to ride my bicycle.”

http://mendiprouleur.blogspot.com/

Posts

  • skyd0gskyd0g Posts: 2,540
    Are you in the smallest cog on the frront when this happens?

    If so, it sounds as if you just need to slightly adjust the rear mech. If it indexes perfectly throughout the rest of the cassette, it sounds as if you just need to slightly adjust the "L" screw. :D

    See here for help: http://www.parktool.com/repair/readhowto.asp?id=64
    Cycling weakly
  • maddog 2maddog 2 Posts: 8,114
    edited October 2009
    if all the other gears are spot on then it will be a limit screw issue, as skyd0g says.

    if all the other gears are also hesitant to shift up to the next sprocket, then it's a cable tension issue, so you need to turn the adjuster anti-clockwise to dial in more tension.

    But just check that click 1 on your shifter is aligned to sprocket 1 (smallest) though, and click 2 to sprocket 2 and so on. I've see this a few times and it will mean that the lowest gear can't be achieved, as you effectively run out of clicks.
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer
  • redddraggonredddraggon Posts: 10,862
    Sounds like the gear cable has stretch a bit, and so the chain isn't sitting on the biggest sprocket properly when in the lowest gear.
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  • maddog 2maddog 2 Posts: 8,114
    first post edited 8)
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer
  • Thanks for all the advice guys, I'm now sorted and dancing (like my Dad at a wedding) up hills!
    “I ride my bicycle to ride my bicycle.”

    http://mendiprouleur.blogspot.com/
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