I've got a 44T sprocket now and it goes 30mph. My bike's a pretty solid set up, handles awsome! I kinda want to go faster. I need to get a new wheel for the back cause it's an old Schwinn S-5 and I'm having a hard time getting some nice new white walls that will fit it. So, I'm going to switch to a standard rim, and I thought why not throw a 32T sprocket on there while I'm at it, but how do I get one and how much are they?