spunkyj

I have a chance to get some late-80s 7-speed Dura Ace STI shifters. I am wondering how well these will work with my 7/8 speed 600 Tricolor derailleurs using Sheldon Brown's "alternate cable routing".

My question is, how good is the alternate cable routing solution? Does this make the Dura Ace brifters and 600 derailleurs compatible or might I have problems? While it would be nice to upgrade from downtube shifters, its not absolutely necessary, and don't want to take the trouble if I'm left with a half-baked system.

I'd appreciate thoughts of all the mechanics out there. Thanks!

spunkyj

bump!

Really, no advice from the mechanics out there? Sheldon Brown says it will work if you "have to use" old Dura Ace shifters with a different Shimano derailleur:
https://sheldonbrown.com/dura-ace.html#alternate

What I want to find out is the meaning of the words "if you have to use". Will it only sort-of work?

TugaDude

I think if it "sort of worked", Sheldon would have admitted that. He says they are compatible. To me, that means functions as intended. You'll never know till you try. I'm sure with the proper barrel adjusters you can get the tension just right and it will work out fine.

urbanknight

I would imagine any alternate method not intentionally designed into the items by the manufacturer would run the risk of not working as well, but if Sheldon thought it was a good idea, it is probably close enough that with careful adjustments, you won't be disappointed.

cycle_maven

I don't know the cable pull ratio of the 600 tricolor series, but the alternate cable routing will definitely work with modern derailleurs to mate DA 7-speed shifters with a 7-speed cassette. Likely it will work fine if the 600 tricolor stuff was indexed in the first place.

Check out: https://www.ctc.org.uk/desktopdefault.aspx?tabid=3946

spunkyj

Check out: https://www.ctc.org.uk/desktopdefault.aspx?tabid=3946[/QUOTE]

Thanks for the link. On that website it says:
"Currrent Dura-Ace mechs are nevertheless designed with an alternative cable route that gives the old shift ratio, so they can also work with old Dura-Ace shifters."

Does the alternate cable routing require a derailleur designed for this in mind? Or can the cable be put in the alternate position for any derailleur. My 600 tri-color stuff is probably contemporary with or older than the DA STIs.

JiveTurkey

Using the alternate cable routing, you can mate the Dura Ace 7-speed shifter with any modern Shimano indexed rear derailleur (whether it says 7, 8, 9, or 10-speed) EXCEPT newer 10-speed Dina-Sys MTB RDs. You need to use a 7-speed cassette.

spunkyj

So "modern" means anything indexed? I.e. my not-so-modern tri-color derailleur will do the trick?

FastJake

Correct. The tri-color 600 stuff was indexed, has the same pull ratio of all the "modern" groups.

I wasn't aware 7-speed DA STI shifters existed. I thought they were all 8-speed.

JiveTurkey

spunkyj, have you used the brifters and know they're 7-speed? If they're off the bike now, remember that there will be one fewer clicks for how many gears it has. So, an 8-speed will have 7 clicks and a 7-speed will have 6 clicks.

spunkyj

I haven't purchased the shifters yet. They've been up for sale for a while now on my local craigslist ($100). Wanted to first determine if they would be compatible with my bike.

The seller claims they are 7400 Dura Ace 7 Sp STI, and in good working condition. I suppose its possible he or she is mistaken about the number of speeds--especially if there is no record of 7 speed on the WWW....

JiveTurkey

Well, if they happen to be 8-speed, then the only major issue will be the need for an 8-speed cassette. So, wait to get the shifter before getting a cassette. Are your rear dropouts spaced at 130mm already?

7- and 8-speed drivetrains use the same chain. Using a 7-speed front derailleur, though, may cause some chain rub since the 8-speed cassette is overall wider than 7-speed.

spunkyj

Thanks for all the advice. Passed on the DA brifters and went with some non-DA ones.