smontanaro 

I think I know the answer, but thought I should check. Will an Accushift six-speed shifter work with an Ultra-spaced six-speed freewheel? I'm thinking, "no", because I had an Accushift six-speed setup which worked on a 126 OLD frame. That must have had regular spacing in the freewheel.

leecycle

Accushift 6sp will work with Suntour "AP" freewheels as well as with Shimano SIS or hyperglide 6sp freewheels.

The Golden Boy 

I have 6 speed Accushift running on 3 bikes- two with SIS 6 speed freewheels one with an IRD 5 speed. I have one bike with Ultra 6 and I haven't even attempted to stick the wheel in one of those Accushift equipped bikes.

Now I have to.

miamijim

In regards to Suntour branded freewheels...it's only compatible with those that have an 'alpaha' symbol or require a 4 notch removal tool.

The Golden Boy 

I thought the alpha indexing was different than both regular Accushift and SIS.

EDIT- I was thinking of the @3000 group- apparently the @3000 shifters only indexed between the appropriate @3000 derailleur.

I guess @4000 and up was normal cable pull.

ThermionicScott 

Would 7-speed Accushift shifters index correctly with a 6-speed Ultra freewheel? In my mind, the math works.

leaping_gnome

I have a 1987 Specialized Allez SE with original equipment Accushift Sprint 9000 and very low original miles. It came with a 6-speed (regular -spaced) Suntour Winner Pro 13-23 freewheel and the shifting worked very well. I swapped the freewheel to an Ultra-spaced AP 7-speed freewheel and changed the shifter from "RE" to "UT." It also shifted very well. The Accushift instructions say that an Ultra 6-speed cannot be used.
From the Suntour cog board the ULTRRAA spacing on a 7-speed is 3.2 - 3.3 - 2.9 - 2.9 - 2.7 - 2.7 and the spacing on a STRAA (6-speed Ultra) is 3.1 - 3.1 - 2.9 - 2.7 - 2.7. So the Accushift indexing mechanism cannot follow both spacing curves with one setting.
I understand that all the AP freewheels have a more accurate spacing tolerance to be compatible with Accushift, and that some "Accushift labeled" 7-speed Winner Pros were also shimmed to pass the "Accushift" tolerance. I will be trying a different Suntour 7-Speed Winner on my Accushift to see how well it works.

smontanaro 

@leaping_gnome What does it mean when you write, changed the shifter from "RE" to "UT"? What are "RE" and "UT"? Neither suggests "indexed" or "friction" to me. Thanks also for the cog board spacing. Might not be perfect, but lining up the last six of the 7-speed with the 6-speed spacings, I get:

Might be close enough, especially with an 8-speed chain, which might have a touch smaller overall width. I might also be able to mess around with spacers to make them line up better.

@ThermionicScott Thanks for the suggestion. I have a six-speed Accushift in-hand. Just looking to hang parts I already have on the frame.

If worse comes to worst, I can always flip the friction switch.

smontanaro 

One thing I find interesting/frustrating is that my left side lever seems to actually be a Power shifter. Why couldn't SunTour leave well enough alone and do Power Shift on the right? Hmmm... I've never disassembled an Accushift mechanism. I wonder if I could replace its innards with some Power Shifter innards.

The Golden Boy 

Suntour Sprint shifters:

smontanaro 

Cool, thanks. Will have to keep my eyes open...

The Golden Boy 

The answer is:

No.

I just put the Phil/Ultra 6 on my Trek 620 with 6 speed Command Shifters.

First 3 shifts without fail. Last 2- unreliable.

First time I clicked through, it was one click, one gear, with a little hesitation into 4th. Then it was wonky going back down.

I would say it's a "no go" at this station.

leaping_gnome

Here's a picture, I mis-remembered the "UT" - it's really "UL":

On the right shifter (left one in the photo) there's a little dial and index mark with the markings "RE" which means "Regular"; "UL", which means "Ultra"; and, I think, "F", which means "Friction". You loosen the D-ring thumbscrew and that allows you to turn the ring to line up the index with the "UL" mark for 7-speed indexing or "RE" for 6-speed (non Ultra) spacing. I should point out that the non-Ultra 6-speed spacing is 3.8 - 3.7 - 3.7 - 3.7 - 3.5.


The Suntour system was designed around minimum mis-alignment. The slop or tolerance in the pully wheels was minimized to make the Accuhift system work. The Shimano STI worked on the oppisite principal - make the gear teeth and ramps do the work and allow more slop in the derailleur and pullies. The Accushift ha a reputation for being finicky and the STI won the day.


I like Suntour but I agree with Golden Boy.