I did several searches and needed to wrap up a few questions regarding putting a MTB-wide cassette onto a road bike with a road-triple rear derailer.
From what I understand, whether on can fit a cassette with a 32-tooth cog depends on whether the jockey pulley clears the big cog. The tension pulley simply determines whether the derailer can pull enough chain such that all combinations can be reached in the derailer drivetrain.
I have a 12-32 speed cassette on an older bike. Would putting on the old cassette and seeing whether I could adjust the b-screw enough to clear the cog be a sufficient test for whether a wide (12-32) 10-speed cassette would work? I think yes.
Thanks for reading and any advice.
Just in case anyone is wondering, I am switching from a triple crank to a compact crank. So I have an Ultegra long cage (GS) rear derailer.
A particularly appropriate old thread ...
Would This Derailleur/Cassette Combination Work?
EDIT: Just to be clear, I would not actually run a chain around the 7-speed cassette. I would simply move the cassette as far inward as possible and begin adjusting the b-screw.