Mountain Biking - Deore Rear Derailer, 8 Speed or only 9?

I was looking at a Deore rear derailer at Performance bike and it says it is compatible with 7, 8, and 9 speed systems. Nashbar says it is works with 8 and 9 speed systems. Everywhere else only mentions 9 speeds. I want to use it on a 8 speed Specialized Hardrock. Any idea if it would work? I thought 8 and 9 speeds used different gear widths.

Thanks.

It will work fine. Most, maybe even all, 9spd derailleurs are also 8spd compatible.

It will work fine. Most, maybe even all, 9spd derailleurs are also 8spd compatible.

Thanks, I just wanted a bit of confirmation before I bought it.

Thanks, I just wanted a bit of confirmation before I bought it.

my hardrock comp came wiht a deore rear der and it is 8sp. Will work fine. ;)

It will work fine. Most, maybe even all, 9spd derailleurs are also 8spd compatible.

So would I be better off going with a Deore LX or Deore XT for the extra $10-$20?

So would I be better off going with a Deore LX or Deore XT for the extra $10-$20?


I could sell you an xt FOR $20. Let me know.....I have like 5 but they all need parts. I plan on calling shimano and getting these parts soon. How soon do you need a derailleur?

I could sell you an xt FOR $20. Let me know.....I have like 5 but they all need parts. I plan on calling shimano and getting these parts soon. How soon do you need a derailleur?

Will the XT work with 8 speed? How good of condition and how much life do you think they have left? I am not in a big hurry, but with in the next few weeks I would like to get one. Mainly by June when school lets out and I have more time to ride.

Also, are they mid cage or long cage? My largest cog is 32T. Does the XT require special shifters as well?

it should work fine with 8 speed. It just wont utilize all the travel thats required for 9 speed i believe. Ive never built a derailleur but im sure thats how it would work. A friend put one on a 7 speed and works fine. I believe it works like this, (btw some one correct me if im wrong) a 9 speed is backawards compatible meaning you can use it on a 9, 8, or 7speed. It just wont go side to side as far as its capable of. But you cant use a 8 speed derailluer on a 9 speed because it can't move side to side far enough to get to the 9th cog.

it should work fine with 8 speed. It just wont utilize all the travel thats required for 9 speed i believe. Ive never built a derailleur but im sure thats how it would work. A friend put one on a 7 speed and works fine. I believe it works like this, (btw some one correct me if im wrong) a 9 speed is backawards compatible meaning you can use it on a 9, 8, or 7speed. It just wont go side to side as far as its capable of. But you cant use a 8 speed derailluer on a 9 speed because it can't move side to side far enough to get to the 9th cog.

yep, that's pretty much it.

To clarify, if using a 9 on an old 7 speed system, you just have to turn the limit screws in further to match the range of the 7 speed system

L8R

on a similar note, can you use a xt crankset with a 7 speed cassette in terms of what chain you use? Will a chain made for 9 speed gearing still work fine with the 7 speed cassette, or would it be too thin? (and can a chain that fits a 7 speed cassette be too wide for a gearing made for 9 speed?) I can't imagine a 9 speed chain would bind or anything on the 7 speed cassette, would it?

on a similar note, can you use a xt crankset with a 7 speed cassette in terms of what chain you use? Will a chain made for 9 speed gearing still work fine with the 7 speed cassette, or would it be too thin? (and can a chain that fits a 7 speed cassette be too wide for a gearing made for 9 speed?) I can't imagine a 9 speed chain would bind or anything on the 7 speed cassette, would it?


read a2's post on this thread. Very informative
http://www.bikeforums.net/showthread.php?p=456682#post456682

Mine are 9 speed. Hopefully I can get around to getting the parts. I will let you know when I do. I was planning on getting short cages for all of them. My largest cog is 34 and the short (or mid) are working fine on the cassette.

Mine are 9 speed. Hopefully I can get around to getting the parts. I will let you know when I do. I was planning on getting short cages for all of them. My largest cog is 34 and the short (or mid) are working fine on the cassette.

Sounds good. Send me a PM if you get them some time soon.