I am trying to get my boyfriend something for his birthday coming up and want to hook up his bike. His bike is mainly stock except tires and hand guards. I am already getting him a 49-50 tooth rear sprocket as I have read its an easy change and makes third gear more usable. What other mods can I do that will help with handling that won't cost me an arm and a leg. Also we usually trail ride, but he does take his bike out to the track with the guys. Thank you for your help!