How to Adjust Your Rear Derailleur
Applies to most 3-chainring derailleur systems. Adjust Front Derailleur
- How to Align a Rear Derailleur Hanger
- How To Install a Rear Derailleur
- How to Adjust Your Front Derailleur
Adjusting your rear derailleur can be frustrating. I’m hoping that this tutorial will help you understand how each component of your derailleur works, and how to set up and adjust it properly. Once your derailleur is set up correctly, most future adjustments can be done by hand. Let’s get started!
Rear Derailleur Components
How They Work
Almost all modern derailleurs function the same basic way. They are designed to move (or derail) the chain from one sprocket to the next. The upper guide pulley (or jockey pulley) moves the chain in both directions. For instance, when you want to climb a hill, you shift down to a lower gear. This pulls the shift cable and forces the guide pulley to change to a bigger sprocket. When you want to go faster, you adjust the shifter to a higher gear. This releases shift cable tension and allows the derailleur springs to pull the guide pulley back down to a smaller gear. Each time you shift gears, the length of chain changes. The lower tension pulley is spring-loaded to take up this slack.
There are 3 adjustment screws – the B-Screw (B-tension adjustment), the H-Screw (high gear limit stop) and the L-Screw (low gear limit stop). Adjustments on these screws should always be made in 1/4 turn increments.
The B-Screw controls the derailleur body’s angle in relation to the sprocket-set. Shift down to the largest sprocket and check the distance between the guide pulley and the large sprocket. If the guide pulley is rubbing on the sprocket, tighten the B-screw clockwise to increase tension and move the pulley away from the sprocket. If there is a large gap between the pulley and sprocket, loosen the B-screw until the pulley rubs the sprocket, and then tighten it until it just clears.
High Gear Limit Stop
The H-Limit screw high gear limit stop prevents the guide pulley from shifting any further past the highest gear and into the axle. In order to adjust it properly there must be no tension on the lower inner cable. If you feel tension, loosen the cable adjuster until there is none. Now check from behind how the chain is riding on the smallest sprocket. If it looks like it wants ride off into the axle, tighten the H-screw clockwise until it lines up. If it looks like it is rubbing on the next gear, loosen the screw until the chain is nicely centered on the sprocket. Now re-adjust the cable tension until the derailleur shifts smoothly down to the next gear.
Low Gear Limit Stop
The L-Limit screw prevents the guide pulley from shifting any further past the lowest gear and into the wheel spokes. Shift down to the lowest gear, step behind the bike, and check how the chain rides on the sprocket. If it looks like it wants to ride into the spokes, tighten the L-screw clockwise until it is centered on the sprocket. If it looks like it wants to shift down, loosen the screw until it lines up. As an extra precaution you can use your thumb to gently push the derailleur body and make sure the chain will not run into the spokes, as this could obviously have a nasty effect on both you and your bike.
The cable tension adjuster defines how far up or down the derailleur moves. Step back so you can see the chain and sprocket alignment, and then through the gears in both directions, first shifting up two and down one, and then down two and up one. The chain should look centered on each sprocket. If it is rubbing on a larger gear it means there is too much tension on the cable. Loosen the tension by turning the adjuster clockwise. If it wants to jump down to a smaller gear it needs more tension. Increase the tension by turning the adjuster counter-clockwise.
You can also use sound to check the adjustment. There is always a base-level of noise that can be heard in every gear. This noise will increase in a slightly different way depending on which way the tension is out of adjustment. If there is too much tension you will hear a metallic rubbing sound, but if there is too little tension you will hear a clicking noise as the chain tries to jump to a smaller sprocket. There is usually a cable tension adjuster on your shift lever. With practice you will be able to make small cable tension adjustments while you are riding.
Now that the derailleur is adjusted, always apply a drop of lubrication to the derailleur’s many moving parts. This will help prevent wear from dirt and rust, and it will keep your gears shifting smoothly. Wipe away any excess lube and take your bike for a test ride to make sure all the gears are working smoothly.
That concludes our tutorial on rear derailleur adjustments… have fun!
- Jim Langley: Rear Derailleur Adjustment
- Park Tool: Rear Derailler Adjustments
- Sheldon Brown: Derailer Adjustment
- Bicycle Torque Specifications
- Park Tool HXS-1.2 Hex Wrench Set
- Park Tool Wrench Combo Set
- Tri-Flow Superior Lube
- Park Tool SA-3 Heavy Duty Shop Apron
- Park Tool SK-3 Starter Mechanic Tool Kit
- Park Tool PK-3 Professional Tool Kit
Discuss this topic in the Bicycle Repairs and Mechanics Forum
Hey guys so I have ~50 years old Cosmos SuperCorsa and the only problem with it is that the rims are bent to the center. I want to replace them but I can't find the exact same brand at a good price. The wheels are from Campagnolo. The bike is 700c with 36 holes. The inner width is 13,5mm and the rim height is 18mm. Are the last 2 measurements not required or it should be exactly as the ones I have...Read more
IMG_0838_resized.jpg (Size: 195.96 KB / Downloads: 14) Howdy folks! Was hoping you all can help me out. I am going to send bicycle parts and tools to help people in Malawi. Was sent this image and told this type of bike is the "work horse" of transportation. From what I can tell they seem to be 1 speed with narrow tires, maybe 26 inch? Obviously pedals might be good too. Any thou...Read more
Could someone help me out? I recently purchased a new single speed bike sprocket. I put it on my bike and I had to make the chain smaller. Anyways I got everything put together and its as if the bike doesn't have enough tension when you pedal. like when you pedal it feels like the chain isn't even on. the cranks spin almost to freely....Read more
So I have a couple of questions that I hope someone in this group might know about or have experience with. This is for my Schwinn Meridian 7-speed trike. 1. Are the derailleur chain and the drive chain the same type? Obviously they're different lengths; and I assume the derailleur chain is a typical 7-speed chain. But what about the main drive chain? Same thing? Or is it a standard single speed ...Read more
I have these Chinese freewheels. On the inside are ridges which are supposed to be there so you can use the tool to remove it. With these freewheels, the ridges are very low. I have a tool, also made in China, and the ridges on the tool are also very low. So when trying to use the tool to remove the freewheel, it does not grip properly, and it can't be used to remove the freewheel. The metal on ...Read more
Hello everyone and thank you so much for having me! I have an older Columbia 3 wheeler adult tricycle and she has a differential, somewhat like a car. I wanted to open up the differential for cleaning and oiling but cannot find any info on her, as to how much oil to add, and where the oil fill point is. Can anyone help me in this endeavor? I'd really love to get her going but don't want to ris...Read more
does this noise mean anything? The bike was not used and left outside for a long time. The freewheel sprocket spun free in both directions. After removing it and dripping oil thru it in both directions it appeared to work fine. Once reinstalled it still works fine, but does make this noise when I stop peddling. With bike upside down and rear wheel spinning freely i can also fell the noise as a vi...Read more
Schwinn Boundary bottom bracket bearing let go. I would like to upgrade them to sealed bearings. Threaded frame bottom tube 35 mm nut thread od. x 73 mm wide....Read more
Hello all. My name is Andrew, and I reside in sunny Bognor Regis, UK. I have been an avid BMX rider my entire life, but my body has taken a battering and I now have arthritis creeping in and if I am really lucky* I will also inherit my mother's osteoporosis. *yeah was being sarcastic. No other form of comedy funnier etc lol. Any way, when my body started to fall to bits and I had a bad BMX wreck...Read more
I have a 1975 Hutchins road bike and want to, if possible, fit a modern crank set, say a Campy Centaur Compact, to the bike. Can this be done and would the existing 1975 front Campy derailleur work? Thanks, Dorsey...Read more
I'm trying to find a 3 spoke or 5 spoke wheel for my virtue hybrid bike. All I can find is for road and fixie bike only. Screenshot_20220522_213714_com.android.chrome.jpg (Size: 30.77 KB / Downloads: 10) ...Read more
I just installed a new set of brakes on a bike at a hostel I've been staying at and I can't get them to work right. First, the front brake lever has a ton of lateral play and they don't have much power when applied. Second, the rear brake arms won't release. It doesn't seem to be an issue of the brake nut being too tight, I can loosen it to the point where I can easily move the caliper by hand a...Read more
Just wanted to drop some positive encouragement for taking your spindle crank out and getting some fresh grease in the cups and on the axle regularly. This will dramatically improve the performance of your drivetrain. For example on how often, I had fully overhauled my bike back in March, when I converted it back to urban street from the snow conversion. It's only May, not even 300 miles on it sin...Read more
First, I'm new here and also Thanks in advance for reading and helping me out. I'm a casual bike rider who lives in a large city and enjoys getting out for a ride in the summer to enjoy the beautiful weather. I don't have a very fancy bike (Trek) but it get's me around just fine. My Problem: I don't know if this is normal on all bike's but I have to put air in my tires every 2 weeks. I've replaced...Read more
I received an update on the purpose of the alternate hole positions for the Stone Oval Chainrings for bolt-on cranks and I wanted to share it here for everyone to learn. This is the information that was provided to me. Hole 1 is for high speed cadence on flat terrain. Hole 2 is for versatility between flat and hilly terrain. Hole 3 is for leverage for cyclists that climb hills often.  ...Read more