Wrongly fitted chain device, where to go now?

jimbo-norco
jimbo-norco Posts: 333
edited October 2012 in MTB workshop & tech
Just bought a Kona Coiler needing a few little bits n bobs doing to it, one of the complaints was that it was skipping gears, I didnt have a good look until i got it home but ive noticed that because someone whos owned it before has converted it to a single ring and chain device the chain is seriously out of line for first second and a similar story for 7th and 8th. Now I know this bike wasnt designed to have a single ring set up so this is probably the cause but is there a way of making it work? If not anyone recommend a cheap dual ring set up to refit and how much a raceface Single ring chain device is worth to sell on? In my eyes I cant see how it will ever work cos if you adjust it to sort the problem one way its gonna throw it out the other way but you never know someone may have the answer! :) thanks in advance!

Comments

  • nicklouse
    nicklouse Posts: 50,675
    jimbo-norco wrote:
    single ring and chain device the chain is seriously out of line for first second and a similar story for 7th and 8th.!
    yes this often happens when zou make a bike single ring.

    what has been done to make you think the chain device has been fitted incorrectly?
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • jimbo-norco
    jimbo-norco Posts: 333
    edited October 2012
    Nah I dont think its been fitted incorrectly,( poor title choice there I meant wrongly fitted as in it shouldnt have been fitted in the first place! sorry for the confusion!) its just not right for the bike and is screwing up all the gears big time, thier all seriously out of line, it cant even reach first and in second the chain is dragging against the wear guides of the chain device badly, similar story for 7th and 8th. I cant see a solution myself apart from refitting the gears to the front but I thought maybe there was a solution or maybe just a slight tweek that could make it perform just a little bit better!
  • The Rookie
    The Rookie Posts: 27,812
    Most dual setups are triples with the large ring removed and no other changes leaving the same angle to the highest (smallest) gears as you have now.

    The single ring should line up with the middle of the cassette, does it? (look across the face from the front)

    Photo's of the setup, the chain guides are designed to be fitted in just this scenario, so of course it should be able to be made to work! What mounting is it? BB, ISCG?
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • jimbo-norco
    jimbo-norco Posts: 333
    it seems to be central and works fine in the middle range of the gears 4,5,6 etc but struggles in the others, heres a pic of the device if it works kona2.jpg sorry I have been out of the bike game for years now and cant remember which mount type is which!
  • jimbo-norco
    jimbo-norco Posts: 333
    oh I have repositioned the wear blocks a bit better since that photo also this pic was taken when i first got the bike :)
  • The Rookie
    The Rookie Posts: 27,812
    Not sure how it rubs the guide in high gear as the guide is above it! However that outer plate looks badly positioned, the curve shape should match the curve of the chainring.

    Can you take a photo of the chain guide mounting?
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • jimbo-norco
    jimbo-norco Posts: 333
    yeah it rubs on the bottom then, pulls at a hell of an angle as it leaves the chain device above the bottom pulley, i'll get a pic in the daylight tomorrow, i believe its the ISCG if I remember rightly but not sure, the 2 threaded holes in lugs around the BB?
  • The Rookie
    The Rookie Posts: 27,812
    3 threaded holes, but yes it 'looks' ISCG as I can see a bolt head at the half past 7 position relative to the BB axis.

    So is it rubbing on upper or lower guide?

    If you have a long cage rear mech that can make adjusting out rub harder as the lower jockey wheel in high gears is a long way forward.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.

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