I just got a bike, the tiers look worn to hell and the back brakes are very weak. The bike is a Specialized Rockhopper They are 26inch wheels, the bike is a Specialized Rockhopper. I will be using the bike on the street more then off road. I do not have a whole lot of money either. Nor do I know much about bikes. I am guessing the weak brakes are from brake pads. Can some one give me some advice on what to get?