1. How to Adjust Your Rear Derailleur

Applies to most 3-chainring derailleur systems. Adjust your Front Derailer

IMPORTANT: Nuts and bolts on your bike should always be tightened to the manufacturer's specifications.
How to Adjust Your Rear Derailleur
DVD Vol. 1 DVD Volume 1
This video is available on DVD

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!

Required Tools

You'll need a rag, a phillips screwdriver, a 5mm allen wrench, and a light lubricant like Triflow or Phil Wood Tenacious oil.

Rear Derailleur Components

Rear Derailer

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.

Limit Screws

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.

B-Tension Adjustment

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.

Cable Adjustment

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.

Lubrication

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!

Tags

Related Links

Discuss this topic in the Derailleur Forums

03/31 Rear Derailleur.. I have no idea what I'm doing

Hey guys, I'm a total novice when it comes to working on bicycles and I read through a lot of posts and I watched some youtube videos but I am really confused on how to get my derailleur back on.  I was trying to get my back tire off to change the tube and some how the derailleur inadvertently "fell off".  Also, a small metal piece fell off with(I did not see any screws land anywhere), which I have no idea where it goes or what it is for.

I don't know hardly any of the biking terminology so it has made it even more difficult for me to understand what I need to do to get it back... Read more >>

03/20 Block spacer

My new 10 speed Shimano 105 block came with a skinny aluminum spacer, which was intended to fit behind the block.  Does this always need to be fitted or is it for special circumstances?  I also have new 10 speed specific wheels and the chain does clear the spokes without the spacer.  The new chain is not smooth under pressure, could taking out the spacer be a solution?   Thanks.... Read more >>

03/14 Hierarchy btw Shimano and Sram models

Dear friends, I wanna buy a bike that will provide me both road and trail usage. and it should be also economical. There are lots of level of quality between shimano accessories such as Tiagra, Xtr.. and also same thing for Sram. Could you advice me the correct hierarchy between models acc to price. And advice a bike for both road and trail usage.Thanks in advance.. http://bikebest.net/versus/... Read more >>

02/16 Frayed derailleur cable end

The metal cap at the end of my derailleur cable somehow came loose so now the cable end has unravelled into multiple strands. They are a cut hazard and look ugly. Appreciate any suggestions on how to fix.... Read more >>

02/15 Since overhaul (I'm Impressed)

It's presently 0 Degrees F, with a -16 wind chill in Chicagoland...

It's been ~3 months since the overhaul of the 2 bikes, and I've been alternating them from the repair stand (Bunji Straps hanging from ceiling joist in basement)..
When I started I figured a squirt of oil was all that was needed.  I had no idea what nice bikes I had! 
I learned about strange part sizes from Here & Internet.
I learned about parts & "Alternate Parts" procurement from LBS, Here, & Internet.
I learned about loose bearings from the first dis-assembly.. and found b... Read more >>

02/12 Deore LX Derailleurs?

I have two Deore LX derailleurs... one is a RD550 and the other is a RD565.
Which one is a better derailleur or is there a better one?? Any differences between the two other than the model number?? Both have the SGS long cage.
Trying to figure out the Shimano numbers and quality grades.
Thanks... Read more >>

02/08 SRAM X9 - Rear Derailleur Pulley - Wobbles

Hello,

I have a Boarman Hybrid Pro (2010 Model - White http://road.cc/content/review/4160-boardman-urban-pro-ltd) and the I have had a lot of repairs on it recently.

After the latest repair I noticed the chain was wobbling from left to right more than what I expected. I bought it back to the bike shop but they gave me lip service on the cause and the repair for the problem.

With further inspecition I noticed that that both rear derailleur pulleys are wobbling and are l... Read more >>

01/26 Need to replace a RD-TZ30 drlr

Hi, I need to replace and old broken RD-TZ30 drlr 7 speed.

Does anyone know if the Shimano Acera M360 7-8 Speed would be an ok replacement?

It is for an old (but much loved) Schwinn Jaguar beach cruiser.

Thanks!... Read more >>

01/02 Rear derailleur help

I took off my rear derailleur to clean my bike and i need help putting it back on. Its a shimano derailleur with the hook. And i have a diamondback mountian bike. If anyone can help it would be appreciated!! I dont remember exactly how it was attached to the frame

Thanx
Jay... Read more >>

01/01 How to determine replacement XT/XTR derailleur?

I have an early 90's Merlin MTB frame with 90's era Shimano xt and xtr on it. I now use the bike primarily as a pavement hill climber (I live in a hilly residential area) with maybe 20% off road. Recently, the front derailleur stopped returning when released by the shifter. The derailleur shifts to a larger chain ring perfectly. When shifting to a smaller chain ring, the shifter appears to release the cable correctly, but the derailleur is not returning, despite obvious slack in the cable. I have to kick it over with my heel. Lubricating the various pivot points did nothing. I assume the... Read more >>

12/30 Chain skipping one gear while shifting

I purchased a 18 speed bicycle with shimano gears having revo shifters yesterday.
Today I noticed that while shifting from 2nd gear to the third gear it skips the third cog at the back and jumps to the fourth. There is no issue with other gears.
I would like to know why has this happened and at the same time what can be done inorder to fix this problem.. Kindly reply.. Smile... Read more >>

12/30 Brifters for old Deore XT 7 speed dérailleur

I've got an old high end Giant mountain bike I'm wanting to convert to a gravel bike, mainly changing the MTB bars to CX/road bars with integrated brake levers/shifters. Any recommendations for some road shifters/levers that would work with the Deore XT 7 speed / triple front derailleurs and cantilever brakes? Don't want to spend a lot, so replacing lots of other components isn't an option.

Thanks for any help you have.... Read more >>

12/14 [Rear Derailleur] Gears up/down by one cog

I don't exactly know how it happened. I've been trying to fix it for days but nothing works.

So let's say you had a 1-9spd derailleur:
If we would want to shift to the biggest cog we would go to the 1st gear, and if we would want to shift to the smallest cog we would go the the 9th gear. BUT that's not the case in my rear derailleur. I could only go to the 2nd smallest cog, and if I would want to shift to the biggest could I would only have to shift 8 times, this means that I would have 1 more shif... Read more >>

12/11 Back bike wheel does not catch gear

i dont know whats really going on but when i was riding my $300 swiss mountain bike i took a brake then got on and tried to peddle. it spawn around w/o catching the back tire. i checked to see if the chain was on, it was. i was having very slow reaction with the front gears with alot of noise before this. i have not used this bike no more then 4-6 times.

if anyone can help thanks. if i can repair it my self i would rather do that since i dont have cash for a repair person..

(but i did notice it started to catch when i go down the drive way (going somewhat speed... Read more >>

12/10 Shifting between first and second

I'm a real novice at this so please make allowances! I was having trouble (front derailleur) shifting up from first to second. When I flicked the shift lever into 2nd, the cage would move across seemingly correctly, but the chain would struggle, make a lot of noise and refuse to shift up. If I pushed the shift lever over a little more - towards 3rd - and held it for a couple of seconds, the chain would move up on to 2nd position and stay there OK. I tried to correct this by increasing the tension a little on the shift wire. The result of that was that it shifts up to 2nd correctly, but wo... Read more >>

New Thread
How to Adjust Your Rear Derailleur
Repair Guide / Help Forums

Free Email Updates: