Derailleurs need adjusting every once in a while, and it’s always good to know how to perform this simple maintenance on the side of the road, where the bulk of your issues will arise. Whether you ride a road, mountain, or commuter bike, and regardless of your skill level, learning the basics of derailleur adjustments is very worthwhile. Knowing how your shifting system works will make you a more confident rider, and could get you out of a pickle should something happen to your drivetrain mid-ride. This tech tip covers basic rear derailleur adjustments, and shows you how to make these adjustments just about anywhere, without complicated tools.
Drivetrain Terminology:
Your rear shifting system has a few key parts. The shifter, usually mounted at the bars, where it’s easy to reach, which pulls cable through the shift housing (the sheath that guides the cable over the frame to the rear derailleur), which pulls the chain up and down the cassette, switching gears.
There are a bunch of reasons you might have to adjust your derailleur; you can have a crash, or your bike can be hit from the side and bend your derailleur hanger, or your shift cable can stretch over time. They’re all reasonably easy to fix, but first you have to determine what the issue is.
Derailleur Adjustment steps:
1. Shift somewhere around the middle of the cassette (exact ring isn’t important). You want to have a frame of reference for your adjustments, and be able to shift both ways for testing.
2. Observe the bike from behind. If everything is adjusted properly your two derailleur pulleys will align vertically beneath the cassette ring that you’re in.
3. If the derailleur isn’t adjusted properly, there are two possible issues: the hanger is bent, or the derailleur tension is incorrect.
3a. If your derailleur hanger is bent, the jockey wheels will be on an angle compared to the cassette ring, ‘curving’ inboard towards the wheel, or outboard away from it.
3b. If your cable tension is off, the derailleur will be vertical, but not aligned under the cassette ring in question. The jockey wheels will line up inboard or outboard of the cassette ring.
4. If your hanger is bent, head to your local Live to Play Sports dealer to get it replaced. Hangers can be straightened, but this is not recommended. The metal is designed to be weaker than the surrounding components, so that it will bend or break, saving your much more expensive derailleur and frame.
4a. If you’re on the side of the road, or the bike shop determines that the hanger is salvageable, it can be carefully bent back. Support the derailleur as much as possible, and very gently bent the unit back to straight, remaining aware that the possibility of snapping the hanger altogether exists. Make this adjustment only as a last resort.
4b. If your hanger is straight, but your derailleur not aligned under the cassette, the adjustment can come from cable tension, via your barrel adjuster(s). Barrel adjusters increase cable tension when they are wound counter-clockwise (moving the derailleur inboard) and they decrease cable tension (moving the derailleur outboard) when turned clockwise.
Observe the derailleur from the rear. If it sits inboard (closer to the wheel) than the intended cassette ring, you have too much cable tension, and need to turn your barrel adjuster clockwise (1/4 turn at a time) to remedy this. If the derailleur sits outboard (away from the wheel, which is more common) then your cable has likely stretched, and needs to be tightened. Turn the barrel adjuster counter-clockwise to make this adjustment.
5. The last step is to test your adjustments. Shift up and down the cassette stack until you’re sure that your derailleur shifts well in every gear. If you have shifting issues only in certain parts of the cassette (gears 6 and 7 for example), check that you don’t have a bent cassette tooth, and double check your hanger alignment.
Tools used:
Super B Hex Wrench Set
LTP part number: 345117-01
MSRP: $31.99
We hope you find this tech tip useful. Derailleur adjustments do not have to be complicated, and knowing your way around your drivetrain is a good skill to have. Thanks for watching, and enjoy the ride!
