important: Nuts and bolts on your bike should always be tightened to the manufacturer's specifications.

How to Install a Rear Derailleur

Removal and installation of a standard bolt-on rear derailleur.

In this tutorial we’ll learn how to replace a standard bolt-on rear derailleur.

Tools

For this job you’ll need a 5mm hex key for the derailleur’s mounting bolt, and a 2.5mm or 3mm hex key for the jockey wheels if you will not be removing the chain to clean or replace it. If you are removing the chain you may need a chain tool depending on your type of chain. You’ll also need wire cutters and a 9 or 10mm metric open end wrench, or a 5 or 6mm hex key to remove and install the rear shift cable. The last thing you’ll need is a phillips (+) screwdriver for adjusting the derailleur’s limit screws.

Rear Derailleur Removal

The first step is to shift your chain onto the smallest rear sprocket. Then pull off the shift cable’s end cap and loosen the cable pinch bolt. Remove the cable from the derailleur.

Now you’ll need to remove the chain from the derailleur. Some chains have a special connector pin that need replacing if removed, so if you don’t need to remove the chain for cleaning or replacement you can simply remove the lower jockey wheel and rotate the cage plate to release the chain. If you are removing the chain, disconnect a link and pull the chain through the jockey wheels.

Now you can unthread the derailleur’s mounting bolt all the way counter clockwise to remove the derailleur.

Rear Derailleur Installation

Before installing the new rear derailleur, apply some waterproof grease to the mounting bolt. Then thread it part way into the derailleur hanger, and rotate it clockwise to make sure the b-screw or tab is sitting behind the flat on the back of the hanger. Then fully tighten the mounting bolt.

If your chain is still on the bike, undo the bottom jockey wheel and thread the chain over the top pulley. Then re-install the lower jockey wheel. If you have removed the chain, re-route the chain through the jockey wheels and reconnect it. Search the site for tutorials on how to use a chain tool or a quick release chain link.

Rear Derailleur Set-up

Now preset the high-limit (H) screw so the upper jockey wheel is roughly in line with the smallest sprocket when viewed from behind.

Thread the shift cable back into the derailleur, pull it tight and tighten the anchor bolt so the cable flattens. Then find a bare stretch of cable and give it a good pull to make sure the cable is seated and has no slack. Then loosen the cable, pull it tight again and re-tighten it.

Now you’ll need to adjust the rear derailleur as shown in previous tutorials. If necessary, trim the cable so there is about 2 inches remaining. Then slide on a cable end cap and crimp it in place.

Related Links

Recommended Tools

Categories

Discuss this topic in the Bicycle Repairs and Mechanics Forum

Hi, I got a cracked shimano DI2 front derailleur (see picture attached). I try soldering it but no luck (probably don't have the right solder). Any suggestions on how to fix that please? Thanks   20230206_170038.jpg (Size: 47.7 KB / Downloads: 9) ...

Read more

Hello, I’ve got an old set of square taper FSA tempo cranks (2x) that I want to swap from a single speed 120 OLD bike to a 1x10 135mm OLD one. Any tips on how to calculate the spindle width for correct chain line? I can’t find anything for that model on the manufacturers website, and i don’t think measuring the one on the single speed will work with the different chain line....

Read more

Help with headset preload

Latest post 1 week ago

First time adjusting a headset and I'd like to get it right. Brand new giant reign with a carbon frame, that I do not want to damage I finally have the preload set to where there is no play but I'm concerned that it is to tight... Stage 1- obvious play/clunk Stage 2- no clunk, but if I lock up the brake and push and pull hard, I can feel some very slight movement Stage 3 - no play or movemen...

Read more

8 Speed on 7 Speed Freehub Body

Latest post 3 weeks ago

Awhile back, I was able to hack a 7 speed freehub body and get an additional speed out of it by using a 9 speed cassette with the narrower spacing. Note that these older freehub bodies are 7 speed exclusive. They do not typically have the space to fit a larger cassette on them. To do this, I took a 9 Speed Dura Ace 11-23 cassette and I simply removed the final combination cog from the back, then...

Read more

How often do you wash your bike?

Latest post 4 weeks ago

Ciao. I know that some bike riders overexaggerate the 'cleaning part' and wash (or spray) their bikes at least once a week. I know, it's mandatory after a muddy trail ride. But I'm thinkging more about daily commuters. It gets dusty here and there, but how long is too long without a shower for a bike? For a bike that rides almost every day....

Read more

I made a video of what my bike is doing. Can someone please watch and help? https://youtu.be/NTu-831CuGM...

Read more

How to lubricate my bike's D-lock?

Latest post 4 weeks ago

Looking for advice. I have repeated problems with my D-lock sticking. I've used standard light bike oil which then leaks all over my hands when I handle the lock. I have some 3-in-one PTFE spray: would that be better?...

Read more

Hi, So I bought a used Schwinn Meridian sight unseen online auction for $59 & drove 8 hours round trip to get it. It appears to be brand new actually. When I got it home, the next day I checked out my score. When I sat on it and pressed on the pedals, they moved but the bike did not. I inspected the bike and realized that whoever put this trike together, forgot to put what appears to be ...

Read more

Hi everyone! I hope you're enjoying a great start to 2023. I'm curious to hear your go-to method for getting a chain truly clean. I don't mean, just looks shiny or is good enough for a quick clean after a ride. I want to know what you do when you want to get every last morsel of ground-up, link-destroying, roller-eating, tooth-gnashing crud out of your chain. The Best Chain-Cleaning Recipe Ever?...

Read more

Patching a tire

Latest post 1 month ago

In the past I have had a lot of punctures. When they happened, I patched the tube, but the holes in the tire were so small, they did not need patching. After many more kilometers, rubber started coming away around two of the holes in the tire, exposing the chords. If I did not do anything, a rock could cut the chords, destroying the tire. I wanted to get more use out of the tire. I cut patches fr...

Read more

Obviously, this doesn't speak for them all, but they certainly might fit! And not even just barely (as suggested by some sources), but with a lot of room to play with. This is another GT Tempest frame that I recently purchased. It's originally a 26" alloy touring bike. As you can see, there's lots of head room, and plenty of clearance to increase the tire size up to probably 38c—maybe even 40c....

Read more

hello I, I just bought a e-trike that has a shimano derailer: Tourney RD-FT35A , is there a higher quality replacement ? thanks tee...

Read more

Help with cassette type

Latest post 2 months ago

I have old vintage road bike from I think 80th. Unknown manufacturer or model. I am trying to replace cassette, but I cannot find this type on internet. Please help. Cassette is 5 speeds with internal diameter 33-35mm. Cassette Hub has 9 teeth equal to each other. 4 speeds are fixed together and screwed by 5th on the top of the hub. Wheels are 27x1 1/4. Thanks for help! Kon   20221122...

Read more

Don't buy plastic cranks

Latest post 2 months ago

I replaced the chain ring on my bike recently. The new one I bought had AVANTI written on the cranks in large letters. I expected, with a name like Avanti, it would be good quality. It had steel internals, and plastic on the outside of the cranks. When I went to accelerate quickly, the crank broke. It turns out the steel in the middle is very thin, thin enough for the crank to break when accelera...

Read more

Cannot get tire off wheel

Latest post 2 months ago

How can I get my Eliminator Grid T9 tire off my rim? I've been at it for about an hour and it just doesn't want to come off....

Read more