Step of 8: Fit And Set Up A Bike’s Rear Derailleur
Index A Bike’s Rear Derailleur
The last adjustment on a rear derailleur is a C-screw. This screw presses on a small tag on the the back of the gear-hanger and adjusts the position in which the derailleur rests.
Set The Shifter
Select the highest gear on the rear derailleur with the shifter and connect the cable. If the cable is already connected screw down all the barrel adjusters. if this leaves the cable very slack unlock the cable and pull the slack through.
Tighten The Cable
If the gear didn’t shift in response to the first click screw the barrel adjuster on the rear derailleur anti-clockwise to tighten the cable until the derailleur shifts into the second highest gear x-1.
Check The First Interval
Check the top jockey wheel is sitting directly under the second smallest cog. Make fine adjustments screwing the barrel adjuster anti-clockwise to move the chain left, clockwise to move it right. Turn the pedals backwards to check the chain is running smoothly on the cog for the second highest gear.
Check The Downshifts
Click the shifter one step at a time going down through the gears onto bigger cogs.
Check The Upshifts
Click the shifter one step at a time going up through the gears onto smaller cogs.
Fine Adjustments to the rear derailleur
If the chain is reluctant to shift onto a smaller cog loosen the cable by screwing the barrel adjuster clockwise.
Shift gear one click without pedalling, then turn the pedals. The gear should shift as soon as you pedal. In use the rider will pedal as they shift so if the system works with this delayed pedalling it’s a good indication that the cable tension is correct.
If the rear derailleur works in the opposite direction. Use the same process but start in the lowest gear and set the first interval to second gear.