Shifters on mountain bikes and road bikes require periodic adjustment to ensure effective and precise gear changes. Shift levers operate the front and rear derailleurs with cables that have a stranded steel inner wire. When you shift up or down by selecting a number on a shifter, the inner wire pulls or pushes the corresponding derailleur, moving the chain to another gear. Adjusting bicycle shift levers is a matter of indexing the tension of the cable inner wires.
Step 1
Ride the bike and shift the front and rear shift levers to the lowest number. Stabilize the bicycle in a front wheel rack or park the bike on its kickstand.
Step 2
Loosen the cable-fixing bolt that secures the cable inner wire at the rear derailleur with a 5 mm Allen key. Turn the barrel adjuster at the derailleur clockwise by hand until it stops. Turn the adjuster counterclockwise one full turn and tighten the cable-fixing bolt with the Allen key.
Step 3
Loosen the cable-fixing bolt that secures the cable inner wire at the front derailleur. Turn the barrel adjuster at the front derailleur counterclockwise until it stops. Turn the adjuster clockwise one full turn and tighten the fixing bolt.
Step 4
Ride the bike at a moderate pace. Shift the rear lever to the next number and note the response of the rear derailleur. If the derailleur fails to move the chain to the next sprocket, tighten the barrel adjuster at the rear shift lever clockwise one turn and repeat the test.
Step 5
Loosen the barrel adjuster at the rear shift lever counterclockwise if the derailleur moves the chain too far and against the next sprocket. Loosen or tighten the barrel adjuster in small increments until the rear derailleur moves the chain effectively and precisely onto the next cassette sprocket.
Step 6
Continue to ride the bike at a moderate pace. Shift the front lever to the next number and note the response of the front derailleur. Loosen or tighten the barrel adjuster at the shifter in small increments until the front derailleur responds effectively and does not move the chain too far and against the next sprocket.
Tips and Warnings
- Shift cables stretch over time. Replace a cable when adjustments are unsuccessful in accomplishing effective and precise gear changes. Maintain smooth performance of shifters by periodically lubricating them with light oil.
Things You'll Need
- 5-mm Allen key
Member Comments