Hey all, Bought this bike at 6k miles so sprocket is probably stock. I want to change to a 15T but I can't seem to be able to slide it out. It seems like the rust has solidified between the spindle and sprocket. I have tried giving it a lot of whacking with a hammer. I went out to get a blowtorch but no luck. I think my next step might be going to get a bearing puller. Or a mechanic.