I really need to lower my gearing, it seems even higher than stock? I haven't really looked at what I have specifically but at 60 I'm already around 4300. 70 is around 5k. Even going 55 around town it seems like it's revving way to high, and I keep thinking I have another gear to go. Would like 70 to be right around 4k, but I don't know if that would make it super slow from a stop. What would be a good rear sprocket I could swap in?