I currently have the origional 21" Rawhides on it, and with the K341 that (supposedly) runs 4000 RPM I get around 20-22 mph. I don't know the tooth count on the driven sprockets off the top of my head, but I will look and post that tomorrow. I am going to put on 24" Argo tires, and would like to get at least 25 mph, but would prefer more like 30-35 mph. When I put in the CH25, I am not going to use a stock exhaust, I am going for dual straight pipes out the side.