Cycling UK Forum

I'm requiring a new cassette and might want to change (increase) the number of teeth on the largest sprocket. So, to work out what my options are, I think the fundamental question is .... do I have a short or medium cage mech? So, how do I know? What exactly have I to measure? Of course, the internet is full of opinion! Is it the entire length? Length of what? Centre to Centre of the jocket wheels? ...and then what should the measurements be for a short and medium?

I'm running Ultegra, 10 speed, triple at the front.

Thanks.

look at the model number on the back of the rear mech; compare with photographs of that exact model, check the specifications if you need to.

cheers