hi i have had my bike for two years now from new but i have just got a job that requires me to travel at 60mph, now bike will reach this speed but only when im maxxing it out, now ive heard that if i change the cog's on it this will make it faster, if so where can i get them from and how much, also is there any other way i can make my back faster, PLEASE HELP!!!, thanx
