I have a few old rear ders in boxes--Dura Ace 7400, 7401 and an old short cage XT der (7 speed era). I used all of these with 7 speed bikes. Will any of these work with 8 speed/130 spacing? Do they have enough travel? Thanks.

yes, on friction.

The Dura Ace will work fine with indexing too. They have spenty of travel. Just remember that pre-7700 Dura Ace derailleurs have unique geometry and need Dura Ace shifters if you are using 8 speed shifters.

Dura Ace 9 speed shifters will shift 8 speed when using a 7400 series derailleur. You hook up the cable the normal way and bingo....it shifts for 8 speed spacing(it's because of the geometry difference between 7400 and 7700 derailleurs). Shimano engineers are pretty darm smart when it comes to keeping old parts running............

Are you sure? I assumed that the Dura Ace 7400 and 7401 rear derailleurs were were built for the 8sp dura ace cable pull, which was uniquely different from the ultegra cable pull that has been kept to till today. In which case they should definitely not work with 9sp shifters.l Or did that only happen in the 7402 and 7403 models?

Positive. As long as you use 8 speed cassette and any 7400 series rear derailleur, 9 speed shifters work. Look at Dura Ace 7700 barcons. They are labeled as "for 7700 9 speed or 7400 8 speed"....It is designed that way. I have a bike that uses 9 speed downtube shifters and everything else is 7400 series. It works perfectly


You are correct about the cable pull. It is different with 7400 series but the 9 speed shifters take that into account and shift for 8 speed. Basically when you click 7700 shifters with a 7400 rear derailleur, it moves the derailleur the proper amount for 8 speed spacing. However when connected to a 7700 rear derailleur, it moves for 9 speed spacing..This only works because the cable pull is different between the 7400 and 7700 rear derailleurs. As I stated in my first post, some engineer at Shimano was really thinking..............

Wrong. Shimano 8 speed dura ace will not work with 9 speed. Even if you fix the cable in a different position, you won't get good shifting along the entire range. Shimano 8 speed ultegra will work with shimano 9 speed shifters. Look it up.

I've heard of it being tried, and I think Sheldon Brown seemed to think that it was possible, but the 9 speed cable pull was matched with the 8 speed ultegra derailleur geometry, which was distinctly different from pre-97 dura ace. I seem to recall that some 9 sp barcons were incorrectly or ambiguously labeled as being compatible with 8 speed. But maybe some people have gotten it to work pretty reasonably?

Unless you've tried it, please don't tell me what will work and what won't work. It works perfectly and it was designed that way. You connect the cable in the normal postion and 9 speed Dura Ace shifters shift for 8 speed when using a 7400 series derailleur...

You are missing the point about the cable pull. You are correct that they matched the cable pull of the Ultegra 8 speed geometry when they designed the 9 speed Dura Ace derailleur but the 9 speed DA SHIFTERS will shift 8 speed when attached to a 7400 series Dura Ace rear derailleur...This won't work with other Shimano 8 speed rear derailleurs.

Bottom line, when you attach 9 speed shifters to an 8 speed Dura Ace rear derailleur, it will shift 8 speed. Again this only works because of the unique geometry/cable pull of the 7400 series rear derailleur.

I run 8 speed Dura Ace right now on a bike with 9 speed Dura Ace shifters and it works flawlessly...........

And by the way, Sheldon confirms what I said.

http://www.sheldonbrown.com/dura-ace.html

Look at the forth line down on the chart. It says that any 9 speed Shimano shifters will shift 8 speed when attached to a 1984-1996 Dura Ace rear derailleur(7400 series). This isn't some backyard mechanic's home remedy. It was designed that way by Shimano

I apologize for having misread what you were saying. I and some others have tried to use 9 speed shifters on 8 speed dura ace derailleurs without success. But reading through your posts more carefully I assume that you were using an 8 speed cassette with an unused click on the 9sp shifter. I've never tried this but that seems very reasonably possible. Sorry for being a knucklehead and wasting your time. Mea culpa!

I'll be using 8 speed Ultegra bar end shifters with an 8 speed casette. I'm leaning toward using the old 7 speed era XT der, which is in the best shape (the DA ders have tons of miles on them). So it will have plenty of travel? Thanks.

The XT will have more than enough travel..no worries

Hey all--

I hope I'm not too late to get in on this thread since it's very close to an issue that I'm dealing with right now.

I have a 1994 road bike with a 7-speed cassette in the back (126mm spacing). It's a Cannondale so there's no hope of spreading the dropouts.

I also have a Dura-Ace 74xx RD. The exact model # escapes me at the moment but the cage is stamped with 6-7 SIS.

After riding a new bike with STI I began to wonder about upgrading my Cannondale's downtube shifters to STI.

It appears, however, that the 7400 series of rear-derailleurs are incompatible with most modern shifters. WHY exactly is this? It sounds like the geometry of the RD's parallelogram results in a different amount of travel per unit of cable pull?

So what? Off to Ebay for some old DA 7-speed downtube shifters?

Thanks for any info-- this is all been rather confusing.

If it's a 7400 series, it make no difference which model. All the 7400 series have the same geometry and amount of travel , and you are correct, it is different than Shimano's other derailleurs. You can go with 7 speed Dura Ace downtube shifters or:

As I stated in my posts above, any Shimano 9 speed shifters will shift a 7400 series rear derailleur when shifting 8 cogs... You just don't use the extra click. They were designed by Shimano to work this way.. You can read the above posts(or sheldonbrown.com) as to why but it works perfectly.

Now here is where I'm going to confuse you:idea:

It will also shift 7 speed since the spacers between individual cogs of 7 and 8 speed cassettes is almost identical ( I don't remember the exact number but it is around a .1mm difference and it's well within the play built into the shifters). You can use 9 speed shifters when using a 74XX Dura Ace rear derailleur and having 7 cogs in the back. You simply don't use the 2 extra clicks. My only caution is while this setup has been used by many people with no problems, but it wasn't actually designed to work that way. In other words, Shimano didn't engineer it to work. People found out it worked through trial and error.