Bicycle Mechanics - Rear Derailleur installation

I'm getting a rear derailleur and am wondering, is it worth attempting to install it myself? Is there anything that I can stuff up on my bike if I try to install it and do something wrong.

Also are there any special tools I'd need, I have hex keys, screw drivers , chain breaker and other normal tools. But nothing special like truing stands, or basically any specialised tools.

#1 thing is to not crush the little tab(s) on the backside on the derailleur pivot bolt. Take a little time to analyse the derailleur and the bike's hanger.

Don't break the chain... remove the derailleur's lower jockey wheel to insert the chain.

Make sure you set the limit screws correctly - especially the Low limit if you have no spoke protector on your rear wheel. Otherwise you might drive the chain into the spokes and ruin your new derailler.

How does your bike shift now? If it shifts OK and you have average mechanical ability, you can just go ahead and bolt on a new rear derailleur. You'll need, at minimum, a set of metric allen wrenches to do it. It's actually a fairly easy thing to do and a rear derailleur is much easier to adjust than a front.

If it doesn't shift pretty good now, I'd recommend figureing out what's wrong before you start changing parts. If your derailleur hanger is bent, for example, installing a new derailleur isn't going to improve your shifting.

It takes patience and some understanding of the bike as well as knowledge of how to use tools. Other than that, it's pretty easy if all your parts are working correctly to begin with.

Go to http://www.parktool.com/repair_help/FAQrindx.shtml

I learned how to do it in a night and after some initial frustration, have gotten quite good at it.

55/Rad

The RD is fairly easy to do, but it can be frustrating when you go to "tune" it.

Look at the park tool site, they are pretty good. Study what is on there both before and after you take it off.

If you think about it, the RD is a simple thing. A spring loaded arm that moves as you put cable tension on it. Release cable tension, the spring brings it back. All of that tension comes from the shifter. The barrel adjuster for the cable is to fine-tune the shifter. The shifter moves it a pre-determined distance (based on the number of gears the shifter was designed to use), and the barrel adjuster just helps you align those shifters to be even with a cog. The upper and lower limits are to align you to the high and the low cogs (and so that they don't go beyond and get caught in the wrong place (spokes). The rest of it is the hangar bolt and special washer to align it right.

Good luck. With some practice, you should find most bicycle maintenance easy. Headsets are hard when you add or remove one, but most everything else is just playing with tension.

Actually, I think the most complicated thing to adjust for a rookie mechanic is the front derailleur. Even after years of turning wrenches, sometimes I get so frustrated, I have to leave it do something else and then come back to it. There are so many different variables and being off just 1/2 a degree messes everything up. Especially with full suspensions mountain bikes where the two halves of the bike move and affect the chain slack. Ah the joys of bike repair!

L8R