AND it was/is so much prettier/classier than the fugly Deore stuff!

Yup.

That is amazing.

Probably. The only drawback of early SunTours is their long cable travel. I originally built the UO-8 for my wife, with Schwinn TwinStik shifters and a SunTour VGT rear derailleur. I had to grind down the right lever stop to secure adequate cable wrap to hit all 5 gears in back, leaving me no motion to spare.
When I have used SunTour derailleurs with early Campag. or plastic Simplex downtube levers, I have had to swing the lever through a wide arc to hit all of the gears.

I've used old Suntour derailers with Shimano indexed levers a couple of times, but there was a catch in that these pre-index Suntour (or shimano or even Campy) derailers feature a " Shimano Dura-Ace 74xx-type" actuation ratio.
So one should either use 74xx index levers with same # of cogs and clicks,
OR
...use any non-Dura-Ace Shimano indexed 7 or 8s lever with a regular-spaced 6s cogset to achieve proper indexing motion with any pre-index-era rear derailer.
OR
...use a Suntour (non-3xxx-series) 7s Accushift lever together with your pre-index derailer and any good index-compatible 7s cogset.

I recommend sticking with the wider standard 5/6-speed cog spacing when using older derailers that weren't made for indexing (though one might get decent shifting using 7s spacing if the cogs are ramped and in their proper sequence).

Never try to make an Allvit derailer index, because it's actuation ratio is unfortunately non-linear.

But even a Gran-Turismo rear derailer will index standard 6s spacing using 6s Dura-Ace 74xx levers (or using Shimano non-Dura-Ace 7/8s index levers), but shifting will be unresponsive unless one drills a new spring anchor hole or two to alter the A/B pivots spring tension balance (so as to bring the top pulley closer to the cogset).
The setup below is not being helped by the sheer length of the old, race-worn cabling up to the non-D-A Shimano 7s bar-end levers (DT levers would shift much better).

Unless the cable stretches to the point that you'd have to re-attach the cable- otherwise, you just move the lever a little further... Maybe I just don't grasp the concept of the barrel adjuster in a friction setup.

The old VX and other decoratively etched/pantographed parts have a much stronger "70s" aesthetic to them- and look totally anachronistic on a mid-80s or later bike.

Every Power Ratchet/SunTour anything combo I've tried worked super. Now I haven't gone higher than 7-speed so I don't know how well the relatively coarsely spaced ratchet teeth would do with the quick shifting Cyclone and narrow 9-speed or higher cassette. (The Superbe friction shifter with that combo is sweet.)

Great job with the experimenting. Interesting (and cool!) to hear about the Suntour indexing. I tried a Cyclone M II long cage on a 6-speed indexed system, and unfortunately it did not work, but digging into this stuff is where a lot of the fun of vintage bike ownership is at!

I've used old Suntour rear derailleurs with Shimano Index shifters. To make taking out cable seating/stretch easier I used a bolt to thread the rear of the derailleur to then accept a barrel adjuster. Or a person could by a proper tap and thread it.

A lot of people just love those old Suntour rear derailleurs as they work so well.

Cheers

I've run a V Luxe short cage with a SunRace 13-25 and Shimano indexed shifters. Worked perfectly.

Top

The Duopar will actually shift to a 38T sprocket and completely handle a 50-42-31 triple and a 16-38 six-speed freewheel, even when cross chaining.



[MENTION=452633]52telecaster[/MENTION] , great job on the gearing experiment. I get all tingly when we push the envelope on our gearing! It's one of the things I miss about living on a flat barrier island. Now I find myself building closely spaced gearing.

That's interesting. I've been playing with mine lately and found it didn't really like a 36 - seemed like the upper jockey wheel was a bit too close. It worked but was noisy and fiddly. When I switched to a 12-32 9sp, the shifting improved dramatically and all was quiet. It looks like your rear wheel may be sitting farther forward in the dropouts than mine so maybe I'll fool around with that. Any other ideas? I suppose there could be a difference in the hangers as well?

pastorbobnlnh - wow, the duopar is even better than I thought!

I generally don't need them as wide as I make them but it never hurts to have the security when touring, and touring is my favorite thing to do on a bike. I have lately invested in some lighter camping gear so I can get by with just two panniers up front, a saddle bag and maybe some front platform stuff. Life's short and I enjoy solo touring.

That jump from 21 to 28 and a step down from the 44 to 26 up front will be a jump from 57GI to 25.3GI.