am i right in thinking i can use a 11-34 cassette with my m970 rear derailleur? the cahin ring is a single 32. and yet when i use the cassette the top jockey wheel seems Very close the the large cog, and a rumbling noise is heard? i have 2 sets of wheels and the other is running a 11-32 and that seems fine.

cheers

Should be fine, adjust the b tension screw in to give a bit more clearance when in the 34t.

Bolt

ah, ok

cheers will try that

Yes, I think I have that combo and it works – with 27/40 on the front.