SunTour Accushift Query/Serendipity!

[WyvernRH]

A while back I acquired Mclachlan road bike http://bicycles.net.au/forums/viewtopic ... =mclachlan Now as noted in the thread it has SunTour GPX Accushift gear levers and I dumped the crappy SunTour Blaze Rear derailleur for a NOS 1970's SunTour VX-S rear derailleur which comes from a period way,way before modern indexing was thought of. I also fitted a modern Shimano 6 speed 14-28 'twisted teeth' freewheel and ran the bike on the 'F' (friction) setting on the gear lever.
Now to the point... I was having problems with the friction setting as the lever kept loosening off causing the derailleur to slip. So out on a run in desperation I looked at the R/H lever which has two other settings 'RE' a short distance ahead of the middle 'F' setting and 'U/L' twice as far aft of the 'F'. So left to right:
'U/L' //////////'F'/////'RE'
Now if you selected either of these other settings some sort of indexing ratchet is activated (neither is a retro-friction setting sadly). Much to my surprise if 'U/L" was selected the derailleur (70's non-index remember) indexed perfectly across the Shimano 6 speed block! Selecting 'RE' sort of worked but not well (slipping, rattly) and not at all at either end of the block which was what I would have expected from an Accushift/Shimano combination.

So, what are these two settings? Did Suntour provide an alternate 'Shimano compatable' setting? I don't remember that and I was around at the time. I rode all the way home in the 'U/L" setting and it performed flawlessly. Is it the combination of the non-Accushift 70's derailleur and the GPX Accushift lever in this 'U/L' setting that allows this to work? I was going to swap the levers for an earlier 'Powershift' retro-friction pair but for the time being I am happily enjoying the serendipity of the working 'U/L' position.

If anyone has any idea what or why the three positions and what the 'U/L' and 'RE' stand for I would really like to know. This setup certainly works a lot better than the Accushift I remember from the late 80's!

Cheers
Richard

[ldrcycles]

Surely it would have to be a happy coincidence, given how much SunTour were struggling to do basic development of new gear at that time I can't imagine they would have taken the time and effort to design Accushift to work with their biggest competitor's equipment.

Like I've said before the GPX group I have works beautifully (i'll be fitting it to my Tarini if the frame doesn't sell before the Noosa Strade Bianche), I can't remember if it has the settings you mention, i'll have to check the next time i'm out at the farm.

[frailer5]

Running these, AFAICanTell, on the Keith Davis Pegasus I have. To a 7-speed Shimano Hyper-Glide. Embarrassed to admit I haven't experimented at all; just going friction. Bernard, the mech who did work on it at Stanmore, before it closed, said something about the indexing (one of them), working pretty well except for either the smallest or largest, (I wasn't listening properly, as I was wetting myself with excitement at the time with anticipation about riding over the Bridge shortly thereafter).
He now works a bit at Ashbury Cycles, so I hear, so I might drop by and pay attention some time.
But, I'll give the indexing settings a shot on my work commute Tuesday. I'm interested in any answers as well.

Of course, these may be a little different to the ones you're referring to.

[Velo13]

Your experience is a happy accident! Enjoy.

During the late 80s and early 90s Suntour had several different incarnations of index shifting, to the point that similar parts a year or so apart would not index together. Of course there were also 6,7 and 8 speed Suntour cassettes and different sprocket spacings ...

However, this lever was designed to cater for three modes:

P is friction (non-indexed) shifting with any freewheel, number of cogs, and spacing (IIRC it has a retro-friction "feel").
UL is for index shifting with the Suntour "Winner System" 7-Speed freewheels (5.0mm sprocket ctc).
RE is for index shifting on a standard spaced 6-speed freewheel (5.5mm sprocket ctc).

UL and RE modes will be designed to work with a specific series of derailleurs including your "crappy SunTour Blaze" which IMHO is a very fine shifting derailleur.

I am a huge fan of frankengearing (see my CX bike here), so am happy it has worked out for you, even if not designed to do so ....

[frailer5]

Butting in here before WyvernRH has a chance to get back... UL sounds like the one for me to try 1st. The Pegasus is '87, reasonably sure, so that could possibly date the levers, although he could have had them in stock from a little earlier.
Good info.

[WyvernRH]

However, this lever was designed to cater for three modes:
P is friction (non-indexed) shifting with any freewheel, number of cogs, and spacing (IIRC it has a retro-friction "feel").
UL is for index shifting with the Suntour "Winner System" 7-Speed freewheels (5.0mm sprocket ctc).
RE is for index shifting on a standard spaced 6-speed freewheel (5.5mm sprocket ctc).....

Aha! Yes, I have found a catalog page on the web that describes it exactly as you say.
http://home.comcast.net/~bobequus/image ... page-1.jpg

I was around when the Accushift stuff hit the market in the UK back in the 80's and I remember that the original stuff was hell on earth to set up and required constant adjustment. Most people skipped the indexing and used powershift or retro-friction gear levers of some other make (Simplex were very popular). Never really understood the attraction of downtube shifters with indexing anyway, especially with SunTour derailleurs being pretty light and accurate changers. That is why I was quite amazed that the mix and match GPX/Vx-S/Shimano setup works so well. Actually it requires two clicks to get onto the smallest sprocket and two clicks to climb back again but only one for the rest of the block. IRRC SunTour did have different spacing on the outside cogs on their 'standard' 6/7 speeds. (not sure about the 'narrow' blocks, I'll have to dig out my old Barnett manual from the period)

UL and RE modes will be designed to work with a specific series of derailleurs including your "crappy SunTour Blaze" which IMHO is a very fine shifting derailleur.....

Hmm, well I must have a bad one then cos it is heavy, stiff in operation and generally badly finished. It compares badly both in finish and operation to the 70's Vx-S gear with which I replaced it. As far as I can tell, the Blaze gear had hardly been used too. The Blaze and GPX stuff (brake levers, gear levers, rear derailleur) appeared to have been added to the bike when it was 'Triathalon-ised' and then hardly ridden at all (maybe cos the gear changing was erratic? ).

As you say I think the UL setting working so well on the Shimano block is serendipity and (in my pessamistic mind) may not last. So, as the friction setting on the GPX levers is really not reliable I think I will have to be switching to some sort of retro-friction lever in the near future.
Cheers
Richard

[jonbays]

I would back Richard on this. I muck about a lot with old 10-12 speeds and I have found old Simplex friction shifters to be the GO to fix the problem. In the day a lot of racers, well those I used to listen to and follow anyway were very sceptical of the indexed shifter as if you had to swap wheels in a race the shift would be no good but with the friction shifter you just trim manually to suit the new wheel you got from your mate or team or whatever no trouble.

[morini]

Just spent the last month riding with Simplex Retro friction shifters due to my modern bike needing work, and they're good, but I tell you after using Campag 9 speed for the last 10 years I've been spoilt rotten. Friction is fun for a while and you need to rehone a few skills but I'm afraid indexing makes it sheer pleasure in comparison. Definitely worth working out Richard.

[frailer5]

UL works a treat. Was right under my nose... er, hand.

[WyvernRH]

Oh dear, sadly the good times didn't last. The changing slowly became more and more erratic and no amount of cable adjustment seemed to permanently fix it. Last straw was when the indexing couldn't hold the derailleur in bottom gear on a hilly ride today. Now I don't know about you chaps but that is one important gear for me! So GPX levers off into the spares box and Suntour PowerShift retro-friction levers on and all is sweet....
Sad, I thought I had actually got Accushift to work for once...
Cheers
Richard

[frailer5]

I'll reserve judgement for now... changing with fingers crossed, if that's possible. Thing is, with the levers on the middle friction position, I was getting slipping off, particularly on the largest sprocket (am very attached to it as well ). No amount of tightening seemed to help. With the UL setting, so far, no es un problema.

[WyvernRH]

I'll reserve judgement for now... changing with fingers crossed, if that's possible. Thing is, with the levers on the middle friction position, I was getting slipping off, particularly on the largest sprocket (am very attached to it as well ). No amount of tightening seemed to help. With the UL setting, so far, no es un problema.

Well if it is working for you stick with it! For me it was good while it lasted. Got to agree that the 'F' Friction setting sucked badly, it slipped anywhere above the middle cog of the freewheel. I have a suspicion that quality control was starting to go downhill at Suntour for the mid-lower end stuff by this point in time as some folk seem to be able to get Accushift to work reliably but others (like me) do not.
I will say that we have a set of SunTour 'Command' levers on our touring tandem which runs a SunTour XCE long arm rear derailleur across a 7 speed SunTour 13-32 freewheel and this has always worked perfectly in index mode. However it has so far been the only time I have got Accushift to work consistently well after many attempts.
Cheers
Richard

[frailer5]

Sorry it hasn't clicked in for you. (apologies for that pun...). My PowerShift levers went with the Sebring when I passed it on. Have to say, it was the only thing on it that I gave a second glance at. They are aesthetically pleasing; and work well. Can always pick some up on the bikerecyclery site, if it comes to it.

[Velo13]

I'll reserve judgement for now... changing with fingers crossed, if that's possible. Thing is, with the levers on the middle friction position, I was getting slipping off, particularly on the largest sprocket (am very attached to it as well ). No amount of tightening seemed to help. With the UL setting, so far, no es un problema.

Well if it is working for you stick with it! For me it was good while it lasted. Got to agree that the 'F' Friction setting sucked badly, it slipped anywhere above the middle cog of the freewheel. I have a suspicion that quality control was starting to go downhill at Suntour for the mid-lower end stuff by this point in time as some folk seem to be able to get Accushift to work reliably but others (like me) do not.

Were you guys running the derailleur cable directly under the BB, touching onto the BB? If so, the constant flex of the BB left and right, coupled with the friction of the cables on the BB surface/paint can work the cable little by little - bu9&ering up your shifting. I always put a little teflon sleeve through there, and the cable through it, to ensure that there is not friction - that might sort it.

[frailer5]

Interestingly, just checked mine, hanging on the wall at work, and said slide-tubes are in place, presumably from when Bernard at Stanmore Cycles did the upgrade stuff. He would have put new cables on.
But I also think my levers are slightly earlier than Richard's. The lever boss markings are a bit different.