I recently replaced the drivetrain on my Whyte Stirling commute bike. I swapped from 34/50 chain rings to a single 38t, and changed the cassette from 11/34 to 11/36 with a new KMC chain to join them. The rat derailleur is a SRAM Rival.
The only problem I've got is that the top jockey wheel sits far too close to the 36t sprocket causing lots of chain rub and when under load, the derailleur won't move down the block.
I've tried adjusting the B-screw but it doesn't improve things. I'm guessing I'll need a longer B-screw (which I'm on the hunt for) though, bizarrely, my old SRAM X7 rear derailleur appears to be exactly the same dimensions as the Rival yet has a shorter B-screw and was used fine on a 36t cassette.
Am I missing something really obvious?
🙂
The obvious thing is a ruval maxes out at 32T while the X7 goes to 36. Im guessing subtle differences you're not spotting make the one work versus the other.
benpinnick - MemberThe obvious thing is a ruval maxes out at 32T while the X7 goes to 36. Im guessing subtle differences you're not spotting make the one work versus the other.
Ah, I didn't know that the Rival maxes out at 32t. I, rather simply, thought that as the X7 and Rival were the same dimensions that they'd function the same.
Thanks for the steer. 🙂