Bicycle Mechanics - chain/cassette noise

I just installed a new XT rear derailleur on my 1990 Fisher Paragon. I tuned it per Shimano's specs. Shifts well until I get to the middle of the 7 speed cassette. From there up, as the chain moves up to the 24, 29, 34 there's a little clicking, like the chain's just kissing the next cog uphill from it. I turned the pedal slowly and noticed a few rivets lightly brushing the cog uphill from where the chain sits. The chain is a SRAM PC51 which is about a year old, riding about 6-12 miles a week offroad. Is it common for the rivets to brush the cassette? I'm sure it's tuned correctly. There's no prob on the higher gears. Maybe just buy a new chain? It's the same chain I had on there before but there was no noise with the old derailleur which was really sloppy in its mounting bushing area. Thanks.

I normally don't answer my own posts but thought this might be of interest. The local wrench felt the pins have moved from their torque of shifting on the steeps. The reason I didn't notice it before was due to the sloppy derailleur. Try a new chain--hopefully the cassette hasn't worn too much with the old one.

[Edited by fongster on 10-23-2000 at 06:32 PM]

I read your first post earlyer today, but i had no idea of what it could be, thanks for the update.

Could it be that your sprocket/chain is wearing and allowing the chain to seat lower in the trough of the sprocket cogs?

This would be a reasonable assumption if your preferred sprocket is the one you are having trouble with now.

Although you are not putting a lot of miles on your bike, you are riding in dirty/dusty conditions which will certainly cause your chain and sprocket to wear faster than under road riding conditions- especially if you are not good about keeping your drive trane clean.

Well what I would advise you look at is the chain line coming down from the jockey pulley (top pulley) of the der. to see if it is in a straight line with the cogs. If not turn the barrel adjuster either clockwise or counterclockwise until it is. Then get on ride it and shift through the gears to see if that got it. If not go replace the chain. If this persists or is worse than go replace the cassette. That should fix it.

I have noticed more times than I care to remember that sram chains do start to get noisy as you work your way up the cassette !...its' shimanos way of saying your using the wrong chain for our HG/IG cassettes....try a HG70 and the noises go away...........

Never ever use SRAM and shimano together, even if people tell you that you can combine parts from the two brands

THEY,RE TRYING TO FOOL YOU!

Well it`s not that serious,but to avoid shifting problems, its best to stay with one brand.

When your changing your derialleur cogs or your sprocket, ALWAYS replace the chain, that should do it.

smoothshifting!

Mark

Mark,
Are you suggesting that if my fairly new bike has SRAM chain and Shimano HG cassette that it might shift better with a gen-you-wine Shimano HG chain. Derailleur is also SRAM. Shifting is OK but could be much better.
Thanks,
Raymond

I would also check the derailluer and hanger to make sure they are perfectly straight. If not, they may be causing problems in the bigger cogs, but nothing else.