Pros: Excellent quality, easy to adjust
The Shimano Deore LX rear derailleur is a reliable, cost-effective part for any mountain bike. It features parts made of high-quality stainless steel and aluminum, and weighs only 285 grams / 0.628 lbs / 10.05 oz.
Also known as part number RD-M567, this derailleur is set up for 8-speed cassette sprockets, however it can easily accommodate higher speeds as well. My bike, a full-suspension GT 2000 XCR 3000, has a 9-speed cassette and the derailleur works very well. Note that the derailleur came with my bike.
I have had this part since October of 2000 and ridden my bike in mud, dirt, and road surfaces. The Deore LX derailleur functioned very well during this time, requiring adjusting only once; which is very straightforward. A knob on the cable as it makes its way into the derailleur lets you adjust the motion of the part along the full range of motion. This makes adjusting very easy. It also has three other screws one can adjust, but I never had to touch them.
Estimated cost for the part is $30 (suggested price) and I recommend it. The derailleur is made of good quality parts, made by Shimano (excellent brand) and shifts fast.
For further information on this part, check out the following web sites:
o Consumer Reviews
I bent the cage (the metallic arm that extends out with the pulleys holding the chain) of this derailleur the other day. I was trying to learn some new maneuvers and fell over, applying pressure with my foot on the cage and forcing it into the spokes of the rear wheel. Aware that that this could push me back some $30, I forced the cage back into place. Fortunately, it only took a few adjustments on the travel of the derailleur and it's working like new again; except the arm is visibly bent (the pulley closer to the cassette is pointing a little to the left)!
Oh well, it works!