Subject: RE: Noisy drivetrain, shimano 105 rear, tiagra front Besides a dirty/sticking chain, noise can be due to adjustment being off slightly. If adjustment is optimal, time to look at other stuff. How many miles on the chain, and could the bike be damaged (crash, bike fall over, etc. )? Carefully measure the chain for 12 in. Measure from link pin to link pin. Should line up almost exactly. If 2nd pin is off by 1/16" chain is worn & should be replaced. A worn chain also causes cassette cogs to wear faster, so may have to replace the cassette too. Look at the rear derailleur (RD ) from behind. The 2 "toothed gears" (called pulleys or jockey wheels ) should line up with the cog they are under. If they are clearly off line then the RD may be damaged or the bracket holding it to the bike's frame (derailleur hanger ) could be bent. A local bike shop should be able to help you out. |