whats the calculation to work out the capacity your rear mech needs (long, medium or small cage) based on casette rings & chainrings? there was a handy website that expained it all somewhere?

So if Ive got 52-30 chainrings and a 12-25 cassette, is it:

52-30 = 22
25-12 = 13

22-13 = 9? so my mech needs a capacity of 9?

Its something like that, but I think Ive got it the wrong way round?

Capacity of 35, surely.

you add them together? ahhhh

…and dont call me shirley

and dont call me shirley

That was way funnier than it should have been. I think it caught me off guard.
😆 😆