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Middle front gear problem

riponsimoriponsimo Posts: 12
edited December 2012 in MTB workshop & tech
Hi,

I have a Carrera Fury, recently bought second hand from the bay...having been out on it a few times i've noticed the same problem happening.

When pedelling with the chain on the front sprocket 2 the chain lifts up from the bottom towards the 3 sprockets which makes the pedals lock up, a slight back pedal and the chain re-sets but the problem occurs again within a few seconds.

At the mo i'm riding with the chain on 3 all the time which makes up hill harder work...any idea why this happens/what needs doing to fix it?

Posts

  • cyclecliniccycleclinic Posts: 6,865
    Cable tesnion probelm.
    1) Shift shifter intp position 1 and turn the pedals. Maybe it will drop into the granny ring.
    2) Release cable from anchor bolt.
    3) wind the shifter barrel adjuster in 3/4 of the way in.
    4) Check the mech cage is parrell to the chain rings and the outer cage is no more than 3mm above or 1mm below the outer chainring when manually moving the front mech out.
    5) use the limit screws top position the front mech when in the chain is on the big sporcket at the back so the chain just clears the cage.
    6) Pull the cable tought and anchor with the bolt.
    7) shift to position 2 hopefull the chain will move to the sprocket. If it does n't wind the barrel adjuster out some more until it does.
    8) down shift to position 1 and turn the pedal. If it does not down shift wind the barrel adjuster in to release cable tension until it drops onto that sprocket.
    9) Shift to position 2 then 3. If the chain mech cage does not move out far enough adjust the high limit screw until it does.
    10) shift to the smallest sprocket on the cassette. The chain should just clear the mech cage when on the largest chainring. Remove any gap by winding in the high limit screw.
    http://www.thecycleclinic.co.uk -wheel building and other stuff.
  • Wow, thank you very much thecycleclinic but that brilliant walk through is beyond my ability i think.

    Maybe i'd be better taking it to a cycle shop for a gears service, or....is the above easier than it sounds to me?
  • cyclecliniccycleclinic Posts: 6,865
    I don't think it beyond you ability. All you need is a 5mm allen key (maybe a 4mm one as well) and screw driver. Eyes help too but there are blind mechanics who do this stuff.
    http://www.thecycleclinic.co.uk -wheel building and other stuff.
  • cooldadcooldad Posts: 32,599
    Indexing is a basic day to day maintenance thing - you can't rush off to a bike shop all the time - just do it.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools
  • Understood, fear of the unknown i suppose.

    I have no problem with weilding spanners and screwdrivers (i kept an Alfa 156 running for 2 years without an issue :roll: ).

    However, in the past whenever i've made the slightest adjustment to a chain, sprocket and derailleur set up the whole thing has instantly gone to rat droppings, as if it hates me with a vengence.
  • cooldadcooldad Posts: 32,599
    Go to 'Read this first' in my sig - Parktools webbie - how to do everything, nice and simple. It's just a bicycle.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools
  • The RookieThe Rookie Posts: 27,803
    There are also some good youtube guides - just make sure you get a good one though!
    Current steed - Whyte T129, 2013 frame, mongrel Revelations, Giant dropper, Stans S1 wheelset. 12, Magura Trail Sport brakes, 1x11. 12.8Kg
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