How to Fix Gear Problems on a Bike

Ninety percent of all gear problems on bicycles are caused by cables. It's very unusual for individual gears to be the problem. Bikes have everything you need to correct most shifting problems through the use of knobs called barrel adjusters that you can turn with your fingers.

The most common shifting problem is a failure to shift into a lower gear when the lever is pressed forward. This is caused by loose cables. You need to tighten them.

Things You'll Need

  • Bike stand or bike trainer that lifts back tire off ground.
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Instructions

    • 1

      Put your bike on a stand and shift it into the smallest gear on the back, the high gear.

    • 2

      Checking the cable to see if it is frayed. If it has only a few individual strands left, it will need to be replaced. Now check the cable housings. These are the plastic coverings that the cable slides through. Make sure the cable housings are all in their stops. The round bullet-shaped ends are seated in corresponding bullet-shaped receivers. If not, pull on them and get them back into the seats.

    • 3

      If the cable is still in good shape, find your barrel adjuster. There's one on the back derailleur, just where the cable enters the housing, and one on the front shift lever on your handlebar where the cable leaves the shifter. It should be a black knob with a smooth, serrated edge--this is what you turn.

    • 4

      Pedal the bike by hand as you watch the chain move over the gear. Reach up with your other hand and as you continue pedaling, shift your bike one click. If nothing happens or there's a scraping sound, it means the bike is trying to shift but does not have enough tension on the cable.

    • 5

      Turn the barrel adjuster slowly counterclockwise until you see the chain move to the next gear. (the next bigger gear.) As you continue to pedal the bike by hand, continue shifting it one gear at a time until you've went through all the gears. If there's any hesitation in the chain, or there's noise, continue turning the barrel adjuster counter clockwise a quarter turn at a time until the bike moves through all the gears smoothly.