How do you fix the gears on a mountain bike?

Answer by  sherwin (31)

there are three considerations, the gear changer (shifter) usually situate on the handlebars, check tightness of cable here, the front derailleur (main chain wheel), check cable tightness here and adjust with adjustment screws for in/out movement and the rear derailleur, also check for cable tighness and correct play with the in/out adjustment screws

Answer by  stever (43)

Check that the levers are set properly in their mounts and that the cables are clean, oiled and not loose, they may need replacing.

Answer by  eatwrite (1559)

Elevate the bike so you can work underneath it. Make sure that you use a "H" screw. Shift to the lowest gear on the left shift first. Then shift to the highest gear.

Answer by  BigBear78 (40)

The answer to this depends on what is wrong with the gears on your bike. It may need a new chain, cables, chainrings, or a freewheel or cassette. Or, it may need none of these and simply need adjustments. A professional bicycle mechanic can help you determine what it needs.

Answer by  esteban (1334)

The two biggest problem areas in bicycle gearing are the derailleurs and the shifters. They usually just need some fine adjustment using a screwdriver. Look for the adjustment screws.