How to Repair a Bicycle

The caliper brakes on 3-speed, 5-speed, and 10-speed bikes are easy to adjust when they don't perform properly.  To do this adjustment yourself, here's what you'll need.

Tools: third hand, adjustable wrench, pliers.

Materials: bicycle spray lubricant, replacement rubber brake pads or shoes.

Time: about 1/2 hour.

Inadequate braking is often the result of a loose brake cable on one or both bike wheels. Place a third hand -- a special tool available at bike shops -- over the brake shoes; use it to draw the brake shoes into contact with the wheel rim.

With an adjustable wrench, loosen the cable clamp nut that secures side-pull brakes or the cable anchor bolt that secures center-pull brakes. Grip the end of the cable with pliers and pull the cable through the clamp or anchor until it's tight; holding the cable tight with one hand, tighten the cable clamp nut or cable anchor. Release the brake.

Test the brake by squeezing the brake lever; the brake should grip when the lever is depressed about 1/2 inch. If it doesn't, the cable could still be too loose; repeat the tightening procedure. Lift the bike so that its front wheel is off the ground, and spin the wheel. If the wheel binds, loosen the cable a bit.

Follow the same procedure to tighten the brake cable on the back wheel of the bike. Test the brake by squeezing the brake lever and spinning the wheel; adjust cable tension as necessary.

Finally, after you adjust the brake cable tension, check the brake levers on the handlebars. If they're stiff or squeaky, spray them with bicycle spray lubricant at the pivot points.

If the brake cables are tight, faulty braking can result from wear to the brake shoes, the blocks of rubber that press against the wheel rims when the brake levers are squeezed. Examine the rubber brake shoes carefully. The rubber should be flexible; if a shoe is hardened or cracked, or if it's less than 1/2 inch thick above the metal mounting plate, it must be replaced. Buy four new brake shoes of the same type; take an old one with you to the bike shop to make sure you get the right type. Change all four old shoes.

To replace the brake shoes, use an adjustable wrench to remove the bolts that hold them into the slots in the U-shaped brake arms on each wheel. Take out the old brake shoes. Set the new shoes into place in the adjustment slots, aligned the same way the old ones were. The shoes must rub only the rim of the wheel when the brake is applied; be careful to position them correctly. Replace the bolts over the brake shoes and tighten them with a wrench.

Keeping your bicycle in good condition allows you to spend more time riding and less time repairing. Use the advice in this article to make the most of your biking adventures.

For tips on caring for and repairing other types of sports equipment, try the following links: