Adjusting Rear and Front Derailleurs
This guide contains important information regarding bicycle assembly. It is intended to be a convenient general reference only. It is not intended to be a complete or comprehensive manual covering all aspects of bicycle assembly or safety. Please reference the Mountain Bike Product Manual for more information
Tools needed include to adjust derailleurs:
- Hex wrench or 2.5 and 5 mm Allen wrenches
- Phillips screwdriver
To begin, set the rear gear shifter to the largest number, disconnect the rear derailleur cable from the anchor bolt, and place the chain on the smallest sprocket.
Next, adjust the high-limit screw so the guide pulley and the chain are vertically lined up with the smallest sprocket. Pull the cable taut, reconnect it, and tighten the cable anchor bolt. While turning the pedals, shift the chain onto the largest rear sprocket. If the derailleur will not move inward far enough to allow the chain to shift onto that sprocket, turn the low-limit screw counterclockwise until the shift can be completed. If the shift CAN be completed, turn the low-limit screw clockwise until the derailleur is prevented from moving past the largest sprocket.
To test, shift through the gears, making sure each gear is achieved quietly and without hesitation. If there are issues, fine-tune the cable tension by rotating the barrel adjuster in the appropriate direction to move the derailleur cage closer to or away from the bicycle. Fine-tuning may take a series of adjustments. On some models, adjustments can also be made at the right-side or rear shifter.
Adjusting Front Derailleur
With both shifters set to the smallest number, disconnect the cable from the anchor bolt and place the chain on the corresponding sprocket and chain wheel. The outer plate of the front derailleur cage should be parallel to the chainwheels, and should clear the chain wheel by one to three millimeters.
Adjust the low-limit screw so the chain is approximately 2 mm from the inner plate of the front derailleur cage. Pull the cable taut, reconnect it, and tighten the cable anchor bolt. Now while turning the pedals, shift the chain onto the largest chainwheel in the front, and onto the smallest sprocket in the back.
If the chain doesn't go onto the largest chain wheel, turn the high-limit screw counterclockwise in 1/4 turn increments until the chain engages. If the chain falls off, turn the high-limit screw clockwise in 1/4 turn increments until the chain no longer falls off but does not rub on the outer plate of the derailleur cage. The outer plate should be about 1 mm from the chain.
To test, shift through the gears, making sure each gear is achieved quietly and without hesitation. Fine-tuning may take a series of adjustments. Refer to the Mountain Bike Product Manual for ways to double-check that the front and rear derailleurs are correctly adjusted.
