How to Repair a Bicycle

A broken or bent wheel spoke can cause further problems with your bike, but replacing it is easy.

Tools: adjustable wrench, two tire irons, wire cutter, bicycle spoke wrench, file, bicycle pump.

Materials: replacement spoke.

Time: about 1/2 hour.

Set the bicycle upside down and prop it firmly in place. Using an adjustable wrench, loosen the nuts that hold the wheel in place; remove the wheel. Let the air out of the tire. Remove the tire from the wheel by hand, if possible; or use tire irons to work the tire over the rim. Starting at a spoke, carefully insert the plain end of a tire iron between the rim and the tire. Holding that end in place, pull the slotted end down and behind the spoke, and hook the slot over the spoke. Insert a second tire iron at the next spoke; repeat, moving the irons alternately around the rim, until you can work the tire off by hand. Then remove both tire and tube.

Once the tire has been removed, you're ready to replace the damaged spoke. On most bikes, the heads of the nipples that hold the wheel spokes in place are covered by a large rubber band. Pull this band over the rim and remove it. If the broken spoke has fallen out of the wheel, examine the wheel to find the empty hole where the new spoke will go. If the old spoke is still in the wheel, cut it off at both ends with wire cutters. Remove any pieces of old spoke left in the wheel rim or the hub.

The new spoke must be exactly the same length and diameter as the old one. To make sure you get the right size, either take the whole wheel to the bike shop or remove a good spoke from the same side to measure by. Don't accept any differences in either length or diameter.

To make the repair, insert the head of the spoke, the end that doesn't have a nipple, into the empty hole in the hub. The spoke head should curve away from the hub. You may have to bend the spoke slightly to get it into place, but don't bend it sharply.

When the spoke is in place, insert the nipple through the hole in the wheel rim and thread it carefully onto the end of the spoke. Hand-tighten the nipple; don't use the spoke wrench yet.

Replace the wheel rim in the fork of the bicycle frame; tighten the wheel nuts. Spin the rim firmly with your hand. As it spins, sight directly down the wheel to see if the spin is even. The wheel will probably be warped away from the side where the new spoke was installed. Stop the wheel and tighten the new spoke a little with the spoke wrench, then respin the wheel and check the wheel alignment again.

Repeat, tightening the new spoke nipple, until the wheel spins freely and evenly. If the wobble persists after you've tightened the new spoke nipple two or three full turns, loosen the spokes opposite the new spoke to correct the alignment.

After you've aligned the tire, check the new spoke to make sure it doesn't stick out through the rim end of the nipple. If necessary, file it flat. Finally, replace the rubber band over the spoke nipples, replace the tube and tire, and pump the tire full.

While riding a bike with a broken spoke isn't dangerous, riding a bike with unreliable brakes is. Keep your brakes in tip-top shape by tuning them up regularly. See the next page for how-to tips.

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