Ok, you dont have to change the front sprocket unless it needs it. I can't tell you what needs to be done without looking at it. I have 12xxx on my front on and its fine for now. I can look at your bike on Tues, Fri or Sun if you want me to, I can tell you what needs to be done in the way of the chain and sprockets. Shoot me a PM with your # so we can arrange a time to get you fixed up.