Dura Ace 7400 compability
 

I have a Dura Ace 7400 7 speed groupset, with 7 speed casette, front derailleur, 7 speed downtube shifters, and i'm looking for the last bit, a rear derailleur. I see most of the 7402-derailleurs is 8 speed, will these work with my 7 speed setup?

Should, but if I'm wrong, this is the place to be corrected.

Yes, it's compatible.

Dura Ace, up through the 8S had a unique pull ratio for the rear derailleur. Your DT shifters will need to be a DA 7s or 8S to match the RD. The other work arounds are to use any 9S indexed shifter with the DA RD or to match a non DA RD with a non DA shifter. Friction shifting is also an option.

Brad

Ok, thanks. I have these downtube shifters:

http://bikeforums.net/attachment.php...hmentid=514627
I may be new to this, so the only thing i know about them is that they are "7 fach" which I suppose is 7 speed... :)
So I can start looking for 8 speed derailleurs aswell? Thank you, make it a lot easier!

despite all the various indexing and ratios- RD's move directly in relation to the indexing (or lack there-of) of the shifter. as far as i've experienced, any shimano compatible RD from 7-10 speed will work with any shifter from 7-10.

I may easily be wrong. just reporting what I have done.

Sorry, DA 740X is the exception, they have a different cable pull than the others.

There are some workarounds, but best to just match 740X with 740X.

Agree with Doc. Old DA has a unique cable pull ratio.
But to answer the OP's Q, the 74xx RD will be compatible with other 74xx as long as the cassette and shifters are matching with respect to the number of speeds.
IIRC some gens of later DA RD's provided an alternative cable routing that allowed compatibility with the 74xx cable pull ratio in addition to the "regular" shimano pull ratio.

Just need to use a 740X RD.

Brad

So the answer is yes.