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-   -   Sheldon Brown's Alternate Cable Routing (https://www.bikeforums.net/bicycle-mechanics/775425-sheldon-browns-alternate-cable-routing.html)

spunkyj 10-14-11 09:51 PM

Sheldon Brown's Alternate Cable Routing
 
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 11-01-11 01:12 PM

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:
http://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 11-01-11 01:26 PM

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 11-01-11 03:00 PM

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 11-01-11 04:07 PM

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: http://www.ctc.org.uk/desktopdefault.aspx?tabid=3946

spunkyj 11-01-11 05:19 PM

Check out: http://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 11-01-11 05:39 PM

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 11-01-11 05:48 PM


Originally Posted by JiveTurkey (Post 13441099)
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.

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

FastJake 11-01-11 08:04 PM


Originally Posted by spunkyj (Post 13441148)
So "modern" means anything indexed? I.e. my not-so-modern tri-color derailleur will do the trick? :D

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 11-01-11 11:05 PM


Originally Posted by FastJake (Post 13441654)
I wasn't aware 7-speed DA STI shifters existed. I thought they were all 8-speed.

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 11-02-11 10:26 AM


Originally Posted by JiveTurkey (Post 13442269)
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.

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 11-02-11 12:52 PM

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 11-07-11 05:01 PM

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


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