Lets play name that noise....please!

Barrzy257
Barrzy257 Posts: 411
edited January 2013 in Workshop
Recently replaced my std double rival chainset to a compact, now my chain has about 2000 miles on it and the chainrings similar( according to seller) now I no they haven't been mated so may be a little odd for a while, but shifting is fine, I'm just suffering with some strange noise. When I'm in the 34t and in the 2nd half of the cassette (middle to 12t) I get a nasty sound, it sound like the chain is maybe rubbing on the chainring, NOT the mechs, it's definitely on the front, it goes in pulses in relation to the left/right pedal downstroke. Now I have the same noise on the 50t and in the same gears on the cassette, but not so long but I think that's to do with me not having the force to keep the power/cadence up. My thinking is I may brew renew chainrings and/or chain, but could someone give me some advice please!
Any help appreciated
Barrzy257

Comments

  • smidsy
    smidsy Posts: 5,273
    I would expect some noise in the 34/12 combo as this is 'cross chaining' and well known to cause such symptoms (as well as increase component wear) and is best avoided.

    Does your front mech have a trim? This can be used to move the mech over slightly to provide a little extra space when you are in the smaller half of the cassette but still on the 34 at the front.

    All to do with chain line you see.

    You can get nearly the same gear as 34/12 by shifting to the 50 on the front and the 15 or 16 at the back.
    Yellow is the new Black.
  • Barrzy257
    Barrzy257 Posts: 411
    Front mech does have trim, but it's not the front mech it's rubbing on, and neither is it cross chaining as I can be 4 out from 12 and get the noise or equally be 50/12 and the noise is there. It's only when I'm on that side of the cassette, and when I'm in the power stroke, I.e so when the chain is highest tension, that I have the noise which make me think a fresh chainring/chain combo is in order?
  • Could it be coming from the hub ... is there any side-to-side play in the rear wheel ?
  • Barrzy257
    Barrzy257 Posts: 411
    Nope, new powertap rear wheel! Definitely coming from chainset/bb area...
  • Could check the chain rings for play at the bolts and make sure that the bottom bracket is installed. it might be worthwhile to take the bottom bracket out regrease and install everything again. Check the chain rings for any kinks or bends. Hope that helps