I have an older mountain bike with a chainstay-mounted U-brake. Its really pathetic, the thing barely stops, compared to the front brake. Its almost not worth having. What are my options for turning this into a better brake? Simply new pads and an adjustment to make sure they're working right? I want to keep it, as replacing it isn't really an option. I don't want to have to send the frame out to a builder who could add canti posts on the seatstays if I don't have to. I want to use this bike for loaded touring, and descents make me nervous with that brake.