I have some into possession of a 600 8 sp. rear derailleur (double), and it seems like replacing my RSX 7 spd. RD (triple) would be an upgrade. Two questions:

1. The RSX RD definitely has a longer cage. Are they interchangable? I was under the impression that a rear derailleur was a rear derailleur. Aside from chain length considerations (I might have to knock a couple links out), is this doable?

2. Is this, in fact, an upgrade? From my research, 600 became Ultegra, and RSX was more or less bottom of the barrel. Now, I'm happy with my RSX RD and have had no trouble, but I like to tinker. Worthwhile?

Thanks for the help.

The derailleurs should be a straight swap, chain length will be OK. Is it any much of an upgrade? I wouldn't bother unless the orignal was worn out. I'd put the 600 aside until you need it.

Fair enough. Thanks.

May as well keep the RSX. If it works well and isn't busted, don't switch it out. I like RSX stuff, personally.

You can swap if you don't need the full wrapping capability of a long cage. If you're running a triple crank with a wide spaced cassette (like a 12-27), you probably shouldn't.

You need to stay with the triple RD if you're running a triple crankset. It's the small chainring and smaller cogs that create a chainwrap problem if you have a short cage derailleur.

Al

That makes sense. I realized that later in the day. The RSX rear works fine, so I'll stick with that.