The brake pads on your bicycle apply friction to the wheel rims in order to stop their rotation. This is a very important part of riding, as a bicycle that won't stop can put you in some dangerous situations. Many old bikes, using old brake pads, will eventually stop working correctly as the brake pad surfaces smooth over time. Rather than buy new brake pads, or worse, a new bike, learn how to increase the friction of the brake pads you already own.
1. Remove the front and rear carbon wheels from your bike. On most older bikes, loosen the two 15 mm axle nuts for each wheel and pull the wheels out of the dropouts of the bike frame and fork. On newer bikes, release the quick release lever of each wheel to detach them from the bike.
2. Clean the braking surface on both sides of the wheels thoroughly using rubbing alcohol. It is important that you do not use soap and water to clean the rims as this will cause the brakes to squeak.
3. Tear out a small piece of 80-grit (or other very rough grit) sandpaper. Use this sandpaper to roughen the surface of each of the four brake pads. Be sure to sand vertically on the pads, not side to side. This will create fine vertical grooves in the brake pads that will help them to grab the rim effectively.
4. Slide the wheels back into the frame and fork dropouts and tighten the axle nuts or quick release levers to secure them in place. Take your bike out for a quick, safe test ride to feel what a difference a little sandpaper and alcohol rubbing can make.