i bought a sram 970 9 speed 11-34 cassette. it is supposed to be compatible with shimano.
i have an hg73 chain and a rmd 761 xt rear derailleur on my road bike. the shifters are sti ultegra. i cnnot stop it from making noises. it looks like the chain and cassette don't mesh together. am i missing something here? the tech at nashbar suggest i send it back and re-order shimano lx m580 cassette. do you have any thoughts or ideas? thanks in advance
pothound

There should be complete compatibility of the chain/cassette in this
scenario. Have you checked the chain for wear? IME you get, at
most, two chains for each cassette ie when you wear out the second
chain, the cassette is toast. So a new cassette with a somewhat
worn chain will not mesh well.

+1 on the chain wear. If you went a along time withthe same chain and casette, a new casette with the old chain will be noisy.

the other thing to check is the adjustment on the rear der. Indexed shifting systems may need a slight "tweak" with a casette change, even within the same brand or series.

"derailleur on my road bike"

Unless you have a "mountain" RDER, it won't handle a 34T cog.

What was the tooth count of the previous cassette?

He has an XT 761 RD. That's fine with his cassette. His problem is most likely a stretched chain with the new cassette

thank you
after studying the problem, i agree. the chain is fairly new so i thought i could use it. the xt derailleur is new. i'm considering a cassette and a hg93 chain. i don't like noise. that should take care of the problem.
i appreciate your help
pothound

OOPS- missed "the small print"

hi sorry it took so long
i bought a shimano lx 11-34 cassette and a hg93 shimano chain. as a test i removed the sram cassette and installed the shimano cassette. i left the old chain on. it worked perfectly, no noise. their must be a slight difference between them. another thought is my chainline could be better. should i install the new chain? what are your thoughts?
thank you pothound

Unless it's a case of simple adjustment, I am truly baffled. Both cassettes are functionally identical unless you got a lemon. I would put the new chain on if it were me- why grind down a new cassette to a slightly stretched chain.

What are the tooth counts of the "old" cassette?
Are both chains the same length?
Was the "B" screw adjusted for the new cassette, if the new cassette is a different tooth count from the old one?

both, the sram and the shimano cassettes are 11-34. i did have to turn in the b-screw. i was hoping each would work the same. shimano prices are getting out of range. maybe a sram chain would have solved the problem. too late, the tech had me send the sram back.
thank you pothound