How much you weigh? You will have to play with it a little to see what you like. What sprocket do you have on the rear now. Whatever it is, I would leave it on there for now until you decide what your front sprocket will be. Once you find out what you want in the front, then start experimenting with the rear sprocket. Im 180# and I started off with 17/42 and then went to 18/42 and now Im going to 19/42. I will probably end up with something like 19/45.