Bicycles are simple transportation, but they, too, can need repair. This Fix-It Guide on bicycle repair tells how a bike works, what often goes wrong, how to identify a bicycle problem, and what parts and tools you will need to fix it. It then gives simple step-by-step instructions for how to lubricate a bicycle headset and other parts, how to fix a flat bicycle tire, how to adjust bicycle cantilever brakes, how to adjust bicycle side-pull brakes, and how to replace a bicycle chain. Single- and three-speed bikes are relatively easy to repair, but those with more speed gears require more repair knowledge and finesse. Many bicycle repairs also cover tricycle repair.
How Does a Bicycle Work?
A bicycle is a vehicle with two inline wheels, a steering handle, a seat, and pedals. The pedals turn the chain assembly that turns the rear wheel for forward motion.
There is a wide variety of bicycles from single-speed bicycles with pedal-controlled coaster brakes to multi-speed bikes equipped with a sophisticated system of derailleurs, freewheels, chain rings, and pressure brakes. The extra components allow the bike to run easily through a range of gear combinations at the touch of a precision index shifter–and help you stop the bike.
When parking a bicycle, use the kickstand to keep it from falling over. If you must lay the bike down on its side, lay it on the left side so as not to damage the freewheel, chain rings, and derailleurs.
What Can Go Wrong with a Bicycle?
The list is short: Lubricated parts dry out. Tires go flat. Brakes get out of adjustment. Chains wear out.
Once you’re done with a ride, make sure you clean dirt and debris off the tires, wipe moisture off components, and clean the chain of debris. If you wipe the chain, lightly lubricate it to replace the oil removed.
How Can I Identify a Bicycle Problem?
- If the fork binds as you steer, clean and lubricate the headset (see below). Regular lubrication of other parts will keep a bike operating at its best (see below).
- If a tire goes flat, you can repair it (see below).
- If brakes do not stop the bike smoothly, you can adjust them (see below).
- If a chain slips or comes off, you can repair or replace it (see below).
- If the derailleur does not operate smoothly or causes the chain to jump gears, see your owner’s manual for specific instructions on adjusting this sensitive mechanism.
What Do I Need for Bicycle Repair?
Replacement parts are available from bicycle shops, some hardware and toy stores, and other large retailers. The tools you will need to fix a bicycle include these:
- Wood block
- Spoons or tire levers
- Bicycle grease (available at bike shops)
- Lightweight (5-10 weight) oil
- Bicycle tire pump
- Chain tool
- Inner tube repair kit
- Air pressure gauge
What Are the Steps to Bicycle Repair?
Lubricate the bicycle headset (handle bar holder):
- Remove the brake cable from the stop. Loosen the stem bolt with a wrench and remove the stem.
- Remove the handlebars.
- Loosen and remove the headset locknut at the top of the headset. Remove other components as needed.
- Inspect all parts (especially bearings) for wear and replace as needed.
- Remove the head tube to access the bottom bearings.
- Clean any metal parts with solvent.
- Lubricate the lower cup with bicycle grease and reinstall the head tube.
- Lubricate the top cup with bicycle grease and reinstall the bearings.
- Install other components in reverse order of dis-assembly.
Lubricate other bicycle parts:
- Remove the brake and gear cables from their housings.
- Lubricate the cables with bicycle grease and reinstall them in their housings.
- Lubricate the brake pivot points with bicycle grease.
- Lubricate all moving parts of both the front and rear derailleurs with bicycle grease.
- Lubricate the chain with lightweight oil and wipe off the excess.
To minimize repairs, remember to lubricate your bicycle monthly. At the same time, check for loose bearings and mounting screws and worn cables and brake pads.
Fix a flat bicycle tire:
- Check the tire’s valve by submerging it in water and checking for air leaks.
- Inspect the tire surface for cuts and holes, marking them with chalk to find them more easily later.
- Use pliers to remove nails or glass.
- Remove the wheel from the bicycle, following the instructions in your owner’s manual.
- Deflate and remove the tire from the rim.
- Inflate the tube and run your hand around it to find the air leak. Mark the leak with chalk. Check the corresponding place on the tire for nails, glass, thorns, or other sharp objects and remove them.
- Deflate the tube and use a tube patch kit to repair the damage, following instructions included with the kit.
Adjust bicycle cantilever brakes:
- Loosen the anchor bolt that holds the brake cable.
- Use a clamp to hold the brake pads in place on the tire rims.
- Pull the cable taut and tighten the anchor bolt.
- Remove the clamp and test the brake. If too tight, readjust.
Adjust bicycle side-pull brakes:
- Turn the adjuster screw clockwise to adjust. If needed, loosen the anchor bolt for additional adjustment.
- Use a clamp to hold the brakes firmly on the tire rim.
- Use pliers to pull the lower end of the cable taut through the anchor bolt, then tighten.
- Release the clamp. If the brake pads remain closed, slightly loosen the cable tension.
- Locate the adjusted brake over the center of the wheel and tighten.
Replace a bicycle chain:
- Shift gears until the chain is on the smallest freewheel cog and smallest chain ring.
- Find the removable link in the chain and disassemble it with a chain tool. Remove the chain, remembering its path.
- Install the new chain through the rear derailleur following same path as the old chain.
- Install the new chain on the smallest freewheel cog and the largest chain ring.
- Add or remove links in the chain for a proper fit.
- Use the chain tool to install and fasten the chain link.
- Lubricate the chain with lightweight oil and test the chain.
Exposed grease picks up dirt. Use kerosene to clean a bicycle chain and other exposed parts.