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!
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
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!
Related Links
- Jim Langley: Rear Derailleur Adjustment
- Park Tool: Rear Derailler Adjustments
- Sheldon Brown: Derailer Adjustment
- Bicycle Torque Specifications
Recommended Tools
- 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
Categories
Discuss this topic in the Bicycle Repairs and Mechanics Forum
NordicTrack U300 Knocking
Lastest post 7 hours agoI'm hoping someone can help me figure out what is causing the knocking sound on my NordicTrack U300 stationary bike. Any help would be greatly appreciated! Here is a video of the knocking sound: https://1drv.ms/v/s!AnBkAt1Ty5oGiGDlEifMjPDihGr7?e=08qsm9...
Read more1962 Varsity - Move Stem Shifters Ok?
Lastest post 22 hours agovarsity.jpg (Size: 152.97 KB / Downloads: 105) varsity2.jpg (Size: 77.64 KB / Downloads: 106) Hi. This is my first post. I have a 1962 Varsity that I've enjoyed riding since I was 10. I'm in my 60's now and just want to putz around the neighborhood. In order to make the bike more comfortable I put a super big seat on it and 12" high handlebars. It's my Lazy-Boy on w...
Read moreHorrendous noises when pedalling
Lastest post 2 days agoI have just started hearing horrendous noises when pedalling my 7 week old Trek Powerfly 4 ebike. The sound is worse than clicking and clunking and I can’t tell exactly where it is coming from. So have uploaded a video here: https://youtu.be/G3X2tLHk4Bk. Has anyone had similar or know what if could be? I’ve not heard these types of noises before....
Read moreGear shift is stuck!
Lastest post 2 days agoOn both my bike handles, the gear shifts are stuck and I can’t move them. They’re currently stuck on gear 5 now (the highest). How do I fix it without needing a new gear shift?...
Read moreBrake wire
Lastest post 2 days agoTook my bike out after a couple of years only to remember that my left brake broke off while using it last and there is an unusual cable hanging from my bike that gets in the way sometimes, is it okay for me to cut it off? Will it affect the right brake?...
Read moreHelp with filling up hydraulic brake lever without bleed kit
Lastest post 5 days agoI bought a can of mineral oil from motorex and it came in 250ml aluminium can with big cap, and I need to fill my brake lever with that oil but I don't have syringe or bleed kit. How could I fill it up without syringe or bleed kit and tips? Anything similar to syringe that would work? 54e2f371.jpg (Size: 152.52 KB / Downloads: 49) ...
Read moreFreehub body change compatibility
Lastest post 5 days agoI have a single speed kona unit with a formula dc52 hub (only single speed drive) and was wondering if anyone knew what freehub bodies were compatible so I can switch is to more then just a single. I would prefer not to have to buy a whole new wheel or rebuilding with a new hub. Thanks...
Read morecable loose from gear handle shifter
Lastest post 6 days agoHi, I'm new here. Just need some help right now for my grandson's Shocker 20 bike. The cable holder has come loose at the gripper handle and having trouble getting it back in. Any suggestions or where to get another 7 speed shifter for his bike? Thanks a lot. Sorry for not filling in any other "newbe" message, I'm currently baby sitting my other grandchild . That probably explains it all. 2...
Read moreWhat’s the name and code for this bottom bracket ?
Lastest post 6 days agoAlso if you guys know the code for the bearings and bearing size, I have a shimano 105 crank B735B1FC-9997-4A08-9590-3B4A5798E21D.jpeg (Size: 79.89 KB / Downloads: 16) ...
Read moreWhat’s the name of this bottom bracket ?
Lastest post 6 days agoI need to know what bottom bracket I have but I can fin a number or code on it to read it. Any experts in here, this is my first post. 006BA1F3-FE4D-4D22-85F0-095E72284B3D.jpeg (Size: 46.12 KB / Downloads: 19) ...
Read moreGrip shift gear on kids bike difficult to turn
Lastest post 6 days agoI've read other threads and lots of info online, and I'm still stuck. My son is unable to shift the gears on his new 6-gear bike. We tried adjusting the derailer to release some tension and tinkered with adjustments here and there, and nothing seems to be working. Is there anything that we can do? I really want him to be able to shift his own gears. Going uphill today we had to stop several t...
Read moreIs the creaking sound coming from pedals or bottom bracket?
Lastest post 1 week agoHello everyone. After many winter rides, my 29er MTB began to throw out creaking sounds last week. It's nothing too loud, just a gentle yet annoying creak that happens on every other stroke but not constantly. Could it simply be the case of pedals (I have clipless Shimano MTB pedals) being "tired" and not the bottom bracket? Where should I look first?...
Read moreworkable fix for low impact easy riding?
Lastest post 1 week agoIMG-0104.JPG (Size: 69.13 KB / Downloads: 14) Hi I was in the process of putting upright handle bars on an old mountain bike frame.. ( help take the pinching out of my neck when i ride) I noticed a small hairline crack in the headset (i guess that is what they are called ?) I am only looking for something i can go out and ride simple flat probably paved trails.. to keep my c...
Read moreDamage done by quick-release skewer on fork dropout?
Lastest post 2 weeks agoHey guys I was recommended to post here to see if I could get any additional opinions. Would be great if you guys could help me out. Images: https://imgur.com/a/HvH98By I bought a second-hand carbon bike that looked mostly fine on inspection but when I took it apart to put in the car I noticed that the carbon around the dropouts might've been cracked? This is my first time seeing these 'enclos...
Read moreCassettes, chains, cranks are they compatible..?
Lastest post 3 weeks agoHi... I bought 2 second hand wheels for my Gary Fisher bike.. The rear wheel came with a new 8 speed cassette marked... Shimano Hypergluide HG. After reading the spec. list of the bike it lists the chain as Shimano CN-IG51, 1/2 x 3/32" ..and the front gear chain as SR XCC-150 42/34/24 crank.. The original cassette was SRAM PG830 11-32 8spd My question ...is the new cassette OK with the original c...
Read more
