49. How To Install a Rear Derailleur

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

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

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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.

Discuss this topic in the Derailleur Forums

05/11 Rubbing on second smallest cog

I did the H and L screw adjustments as described on site then release the cable by bolt after all turned the barrel adjuster Clockwise to loose the cable tension, turned it two half turn then tight the bolt.I haven't any noise or ticking noise except the second smallest cog.When the chain on it some ticking sound appears.I found the cable tension not enough only on second smallest cog if i push the lever a little bit sounds disappear because when the chain on that cog the jockey pulley is rubbing the inner side of the chain one or maybe twice on 1 full turn of cog. If I apply more tension to ... Read more >>

05/10 Acera / grip shifter lubrication ?

I got a nice shape woman's Trek 820 for free, checking it out for my girls, shifts fine, grip shift works well but you need to apply some twist to move it from gear to gear, is there a way to lubricate the grip shift itself or is it a tight cable issue? thanks... Read more >>

04/28 Shimano 105 (rd-1056)

So I basically know very little about bicycle repair (not technical by nature either), but I found an old racebike just missing wheels, a steer and pedals. I managed to get everything together and in working order, but somehow i can't get the shifting from my back wheel right. I did the thing with the limits (H and L screws), and I tried turning the adjusting barrel, but the shifting of the highest (smallest cogs right?) four out of eight gears doesn't work properply (up nor down). It's like I shift perfectly for the first four, then only shift half a cog, so I have to shift twice, and from t... Read more >>

04/23 Shimano 105 problem

Greetings all, new to forum, bit of help required. I have recently upgraded my Felt z95 from Shimano Tiagra cassette and rear derailleur to 105. I'm an amateur but have tinkered successfully with a few set ups, but this has got me stumped. I've set the limit stops and B tension screw according to various instructionals, and cable tension appears ok. Shifting is fairly sweet but when I'm in large chairing and work up to the 3rd and 2nd largest sprocket the angle the chain sits at in the derailleur cage causes the whole rear mech to jump and grind. The chain is angled outward as if the ... Read more >>

04/22 Derailleur Hanger

After pulling off my rear derailleur I noticed that my hanger has significant play against the frame. I tried tightening the bolt but it won't tighten anymore, when I loosen it it still only tightens to the same point. Any ideas? Thanks Benen... Read more >>

04/21 Gear issue Noob needs help please!

Hi. New to the forum and looking for some help/advice. I have been riding for last few years on a specialized mtb. I have only done very basic maintenance myself relying on LBS to do anything I deemed "too difficult". Recently I decided (after getting fed up with the cost of some of the repairs) to have a go myself. So I have replaced the chain and cassette and new pads etc. all ok except that when I have the bike up on a stand the gears change flawlessly. However when I am riding I see an issue with shifting up a gear and the gears not shifting. If I shift up again it then changes 2 gears.... Read more >>

04/21 X9 Derailleur Overhaul

Hi all, I've been giving my entire bike an overhaul bit by bit over the weekend and am up to the rear derailleur. Most things have been no problem so far. I'm just curious on the best way to go about it. I've dismantled the derailleur. Most things I have cleaned in Kerosene (chain, cassette etc.) and then rinsed in hot water, dried, re-assembled and put pack on the bike but my jockey wheels have a cartridge bearing and I'm not sure if u can just dunk them in kerosene and attack with a toothbrush? I don't want to do any damage. Thanks Benen... Read more >>

04/12 Gear Adjustment problems

[attachment=4072]Hi there am new to the forum and guess what i have a problem have an old Raleigh pioneer 21 that i cant bear to part with. Especially after some bad experience with brand new bikes anyway just put on a brand new old stock derailleur and cable connected to early shimano rapid fire shifters if i set it up to go from 1 to 7 smoothly but wont go from 7 to 1 and vice versa have a cycle haynes manual and set it up by the book and looked on internet what everway i set it up doesnt work was the same with the old derailleur thats why i relaced it... Read more >>

04/12 Chain leaves rear roller

I have a SRAM APEX 9 speed system (2 chainrings) 3 years old that has worked well until I took it apart to clean it. I put on a new chain too. Now in high range/low gear (crossing over) the chain jumps off the distal derailleur wheel, causing me to have to get off and reposition it. It is clear that the angle of the chain going from the big wheel on the cluster to the big chainring is causing this. It seems like the guides on the sides of roller wheel should be close enough to prevent the chain from jumping off. Did I put it back together incorrectly? Is the chain too short ? All opin... Read more >>

04/08 Is my front derailleur bent?

Hi all. I'm new to repairing my bike myself, but I got so fed up with the dishonest or incompetent shops in the area that I've decided to just do things myself. So far all I've done are change a flat tire (and install rim tape and wheel liner while doing that) and just now I replaced a gear shift cable. anyway the background to my question is as follows. A couple months ago one of my pedals broke off. Although I had already started fixing some stuff myself, I brought it to a shop to fix as I didn't have a pedal laying around, not expecting that to break, and I need my bike, I ride it a ... Read more >>

04/06 Suitable Sachs Huret front derailleur replacement

Hi I Got given an old Peugeot Premiere racing bike by my next door neighbour at the end of last year, I think it is around '84 vintage, it has a pearlescent white frame with blue stickers, it's quite a retro bike and they seem to go for reasonable money on ebay. The front derailleur is a Sachs Huret and the internal face that pushes the chain away from the down tube has worn through the plating and is rusting badly. I was thinking of trying to find something new old stock to bung on it, something Shimano would be good, there are lots on ebay with prices starting from £1 so hopefully a chea... Read more >>

04/02 Shimano 105

Hey guys, I am new to shimano 105 basically new to cycling (last bike i bought was 20 years ago) and bought a charge juicer high. A great bike but seems like the derailers are a bit off. I took it back once so far for adjustment but after about another 30 miles they went back to not quite right. The rear doesn't shift right when in the low gears and the front shifts slow when going to bigger sprocket. Any ideas or is 105 just this?... Read more >>

04/01 Top 2 gears - hop

I replaced the chain on my daughters bike. Now it won't stay in the top two gears (6 and 7). It constantly hops out and back in. The rest of the gears seem fine. It doesn't matter what gear the front derailleur is on. The back cog is 7 speeds. The chain is an 8 speed chain, but as far as I can tell they're the same. The length of the new chain might be one link shorter. I adjusted the tension on the derailleur as best as I could. The derailleur seems a bit bent as the wheels don't line up with the gears. That's my first guess as to the problem, but it used to work fine. Any ideas on what I s... Read more >>

03/31 Shimano RD-TY22 7 blew up

What inexpensive RD should I replace it with? Will a RD-TX35 bolt right on?... Read more >>

03/28 Jockey Pulleys

I foolishly did not remove and clean my jockey pulleys (Acera derailleur) one at a time, and see that one has a metal sleeve inside the ring, and one does not. Both bushings seem to be the same length. The metal-sleeved one is slightly thinner. From my reading, it seems that this one is the "top" one (closest to the freewheel/cassette) that because it is thinner, it "wobbles" to make shifting easier. Do I have it right that I put the thinner one on top?... Read more >>

Bicycle Tutor

49. How To Install a Rear Derailleur

Tools

Rear Derailleur Removal

Rear Derailleur Installation

Rear Derailleur Set-up

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