49. 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.
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.
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.
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.
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.
I just changed the Altus lever (ST CT-15) on a mountain bike that had been sitting in my basement for a while.
Using the lever, I can't have the front derailleur move up or down (left or right) for an unknown rea... Read more >>
I have a Scott Sub (hybrid) from 2008. The stock components (mostly Shimano mountain bike components) were old and wearing out so i decided to strip the bike and replace pretty much everything with new and upgraded components. I decided to change the drive train to road bike components (a 10-speed rear cassette and a two-chainring set up front) and went about purchasing them.
Put everything on with the last major part being the front derailleur and it was here I ran into a problem. I’d bought a Tiagra front derailleur, FD-4600-B, and when it came to attachin... Read more >>
I have a 2012 Sram Red Groupset. I was replacing the cable for the front derailleur yesterday and i must have done something because now its fucked. Now when I put the cable in and attach it to the front derailleur it will not click into the correct position. The front derailleur will still move up onto the larger ring but after I take my finger off the lever it goes back into the smaller ring. Does anybody have any experience with this? what happened? adn how do I fix this?... Read more >>
I'm quite attached to an old Mongoose "Hilltopper" mountain bike. It's perfect for it's role taking me back and forth to the metro station. Sturdy, comfortable, and not likely to be stolen.
Unfortunately, the Suntour alpha 3000 6-speed rear derailleur is toast. Is there anything I can buy that will replace it?
eab... Read more >>
Hello. I'm new to this message board - thanks for reading this.
I'm almost at my witts end with adjusting my wife's mountain bike. It's about 15 years old, Specialized brand 21 speed. Original Shimano shifters seem to be locked up - I've read that the grease hardens over the years. I tried loosening them up with Brake Clean spray, but to no avail.
I found a new pair of Shimano Shifters online (Amazon Prime) with very good reviews, so I decided to completely replace the ones that were on the bike.
The installation was easy, but adjusting the shifters - front ... Read more >>
The other day I bought a mountain bike secondhand and have been researching it's problems trying you find the best solution. I managed to reattach the rear brakes after the cable had come out of a couple holders on the frame. I put air in the tires and took it for a test run only to find that the gears, which I fully expected to give me trouble, not only don't work so great, they actually won't shift at all. Both shifters (twist shifters built into both handles) click when turned, and visibly affect the cable tension, which does seem loose to me (though I know nothing about bikes). I used the ... Read more >>
I've followed these instructions
to adjust the front derailleur on a 90's MTB with 400LX components and I think I've done things right, but the chain keeps jumping directly from the outer chainring to the inner one.
Thanks... Read more >>
My 11 speed has become an 8 speed. Thought maybe cable slipped/stretched/frayed. Nope. Limit screws are right. It wont hit the final 3 smaller gears. Physically pulled the cable and it would track down the final 3. Tightened the cable anchor. Got it to shift to the bottom but woudnt shift to the top three gears. Removed the cable from the anchor and pulled it. Started working the shifter while holding tension on the cable. Im only getting 8 detents from the shifter.
What happened to my shifter?
Thanks for the help in advance... Read more >>
I want to swap the racing handlebar brakes/gear shifters for normal v brake levers and thumb shifters - however the only affordable shifters I can find are for 21 speed (3x7) and my bike is only 14 speed (2x7). Can I set it up so that both the 2 and 3 on the left (front hub) shifter just cause it to be in 2 (because there is no 3rd gear on front)???
Hope I phrased it in an understandable way! its hard to write it out without pointing at stuff ... Read more >>
I wonder if anyone can help with an issue I'm having with my rear derailleur.
I'm not really sure how to describe this but you can see here http://tinypic.com/r/2cwogbb/8 (direct images not working...). Basically when changing gears, the mech (which has recently been professionally fitted) locked up in the stretched out position and now I can't get it back. It has happened a few times before and released itself, but no joy this time.
Sorry if this is discussed el... Read more >>
I bought a very old Mongoose mtn bike from Goodwill for commuting to/from the metro station, and would like to replace its very old Suntour 3000 alpha rear derailleur. Is there a model of derailleur I'm likely to find that will allow me to keep the index shifting? Or should I give up and buy any old other derailleur for continuous shifting?
Thanks!... Read more >>
My bicycle had been shifting erratically on its own. I downshifted and immediately after downshifting a loud CLUNK jammed my tire. This is what the damage looks like---is this ... Read more >>
i bought a raleigh mtrax ht 1.0 but the hanger from the Rear Derailleur is missing ive been in a few bike shops and they are unsure what hanger i need. i've been online and there are hundreds of different shapes and don't want to start wasting money on hangers and they don't fit so if anyone knows the type of hanger i need would be very helpful
here is a stock pic of the bike
I have found what one... Read more >>
i have Hunter Shadow from years ago, probably the 80's, not a high end bike from Hunters in California.
it has 1.25" tubing. i sent it to a bike shop a year ago because I couldn't remedy it and they did a home made type of repair. the bike would never shift into low. same after they repaired it. no difference. the derailleur is the wrong one as it had no cable stop to attached the sheath or jagwire that fed up from the bottom cable stop.. now to the chase. i removed the front derailleur and the small and large chain rings and now have a 36 tooth middle chain ring left on the same crank... Read more >>