Bicycle Mechanics - Are pre-STI front derailers STI compatible?

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Gonzo Bob
09-11-04, 11:14 PM
I have an old bike from the late-80's with Shimano 600 7-speed indexed downtube shifters. Can an STI shifter work with the front derailer (double)?


seely
09-11-04, 11:18 PM
Nope... it will work on the rear though. I have a 9spd Tiagra STI on my 8spd 600. Dont ask why but it hits all 9 gears. One of the guys I worked with turned me on to this... not sure if all the 600's were capable of 9 though.

capsicum
09-11-04, 11:19 PM
Why would do you want sti on a double front, if I may ask? Just set the high and low stops on the derailer an thats it, just flip the friction shift lever all the way, one way or the other, boda boom shift complete.


Gonzo Bob
09-11-04, 11:29 PM
Why would do you want sti on a double front, if I may ask?

Well, it's more a matter of looking into STI for the rear. The rear shifter isn't indexing so well any more. So I'm looking into switching to STI and was wondering if I should get a pair of levers or just the rear.

Indolent58
09-11-04, 11:43 PM
Shimano 8sp STI is compatible with Shimano 7sp, at least for the rear. Sora is the only 8sp group still in production, but you can pick up older Ultegra or 105 levers on eBay. But since STIs do develop slop over time, you may be better off with Sora.

The question in my mind would be why your rear isn't indexing well now. Indexed downtube shifters are dead simple and don't wear out easily. If the shifter itself is still giving you positive clicks, the problem is more likely in the adjustment, the cable, and possibly the rear derailleur.

Gonzo Bob
09-11-04, 11:50 PM
If the shifter itself is still giving you positive clicks...

It's not. Most of the time it still settles into gear. But it's slowly getting worse and eventually it will probably fail.

I googled this and found that pre-STI FDs may work OK with an alternate cable attachment...

"This isn't a DA-vs-Ultegra incompatibility issue; rather the
FD-6400 derailleur predates STI levers. When STI appeared,
they made new front derailleurs with a shorter arm so that
the der moves farther for a given cable pull.

Peter's suggestion of clamping the cable on the side of the
clamp bolt nearer the pivot shortens the lever arm and should
work. I even got an STI triple to work this way, though it was
a bit marginal and had more cable rub than is desirable"

capsicum
09-12-04, 02:43 AM
Just switch the rear if thats what you want. Don't worry about the front, or just get a friction lever for the front if the index is worn out. Heck even pro racers use STI rear, with a friction front.(Armstrong for example).

You may be able to put a 9 speed cassette on that hub, I don't think they are any wider, then you really have options. I know 8 and 9 speed mtb cassettes are the same width but not sure on road.

sydney
09-12-04, 06:59 AM
It's not. Most of the time it still settles into gear. But it's slowly getting worse and eventually it will probably fail.

I googled this and found that pre-STI FDs may work OK with an alternate cable attachment...

"This isn't a DA-vs-Ultegra incompatibility issue; rather the
FD-6400 derailleur predates STI levers. When STI appeared,
they made new front derailleurs with a shorter arm so that
the der moves farther for a given cable pull.

Peter's suggestion of clamping the cable on the side of the
clamp bolt nearer the pivot shortens the lever arm and should
work. I even got an STI triple to work this way, though it was
a bit marginal and had more cable rub than is desirable"Yer right.It isn't always a given that it works.More likely with a double than a triple tho.