vintagerando

I just got a bunch of parts in one purchase. I am missing the rear derailleur from a Ultegra 6500 group set. Can I use a Shimano 600 (rd-6400) with the Ultegra brifters (STI)?

Bill Kapaun

Supposedly-
VeloBase.com - Component: Shimano RD-6400, 600 Ultegra

bradtx

A possible problem will be whether the 6400 RD, if the 7S model, can span the wider 8+ cassette and shift into the innermost cog. This is also dependent on the width of the dropouts.

Brad

FastJake

The cable pull is the same so yes, it will work with your STI. I've used the 6400 7S RD to shift 8 cogs before and it reached. It worked for me, so I'd guess it will work for you too.

HillRider

I've successfully used "7-speed" Shimano rear derailleurs to shift an 8-speed cassette with 8-speed STI brifters on two different bikes. One was a '92 Deore LX derailleur on an old MTB with 135 mm dropout spacing that I "roadified" and the other a '92 Deore DX on a road bike with 128 mm spacing (took both 126 and 130 mm hubs). So, yes, it will work.

dtrain

Isn't 6500 9-speed? Should be fine...but double-check that cassette/chain and STI match.

Slash5

I have that same derailleur running 10 speed index with no problems.

bradtx

Perhaps I should have written thickness of the dropouts, rather than width, which would imply OLD.

Brad

FastJake

I understood what you meant but thinking about it some more, I've run 7S RDs with 8 cogs many times on steel, aluminum, and probably carbon frames with various thickness dropouts and never had one not reach.

Eric S.

I'm currently running a 7sp-era Ultegra derailleur on a 10sp cassette and 10sp Microshift bar con. Works fine!

Jordanmilo

I hate to wake up such an old thread but I'm trying to get my 6400 to index on a 7x2 drivetrain and am having problems. Here's a link to the topic I started; I'd be grateful for any advice. Thanks.