thook

hello peoples,

i have two 7spd suntour AP freewheels i'd like to try and use on two different builds. for shifting, i'd prefer some barcons or perhaps the command shifters...whichever pops up at a price i can manage. obviously, there are downtube shifters, but i don't care for them off pavement which i do alot of. a few technicalities on AP shifters are beyond me, though.

first, is the front shifting friction?
second, is the rear friction/indexed or just indexed?
third, do i need a set of AP specific derailleurs? (moot on front if friction). i have some suntour friction rear cyclones (two MkII's and one 3k) and one X-1 rear labeled as AP from an early giant boulder atx mountain bike.
fourth, some of the AP shifters i see on ebay say 5/6/7spd compatible. i'm assuming that simply means the spacing is the same across, but i wonder if maybe the 6spd shifters might luckily have that "extra" click like my old shimano XT 7spd thumbies have (making them capable of shifting 8spd) ???
lastly, if DT shifters are my only affordable option, will they only mount on bosses or will they mount on a suntour downtube clamp? or, (just occurred to me) will they mount on bar end pods of suntour or other brand? if the latter is the case, then DT shifters would certainly be another option for me

as a side note, what's the best way to lube the freewheels without dismantling them?

thanks a bunch!

clubman 

Complicated. If you can read this and get it, you're all set.
https://www.yellowjersey.org/Suntour21.pdf

Classtime 

Yep. You have to love Suntour to go Index. Fun idea though to build TWO bikes around a couple of exotic free wheels. Try two wheel sets and one bike first. I will likely try again but my first foray into 7 speed Suntour Acushift did not go well.

clubman 

I've has 7 speed barcon indexing work well twice. 8 speed is a crap shoot. Far less tolerance in the setup of Suntour.

dddd

Use Accushift shifters only with Accushift derailers (note that 3040-series parts are only compatible with each other).

For 7s Accushift, it's best to use 9s Shimano chain, and use only Accushift or Alpha 7s freewheels.

Lube the shifter internally to enhance indexing.

You don't want anything to do with the index-friction setting, which combines worst features of both, only worse.

Accushift 7s always works well for me when I abide by the above!

You can mount Accushift DT levers on almost any clamp as long as the inner hub of the shift lever is rigidly attached to the clamp and the lever itself doesn't rub on anything.

T-Mar

Accushift Plus was SunTour 2nd version of their Accushift, indexed shifting system, upgrading it be Shimano Hyperglide equivalent. The main change was revamped freewheel cogs with new profiles and gates, to improve shifting, particularly under load. There was also a modified Accushift Plus chain and Powering chainrings, to improve shifting. The shift levers included a friction mode similar to a light index whereby the levers still clicked to guide the cyclist in gear selection.

The front Command shifters that I've seen have been a Power Ratchet friction function. The rear is selectible indexed or friction/light index.

Accushift Plus was designed to be backwards compatible with Accushift derailleurs but not pre-Accushift derailleurs, though some members have reported success in getting pre-Accushift derailleurs to index. I haven't heard of, or experienced the 3040 incapatability issue.

Most members lubricate freewheels by cleaning them off well, then dribbling light oil along the gap between the inner and outer bodies. Spinning the freewheel as you do this, faciltates drawing the oil into the body.

scarlson 

I've gotten Accushift 7-speed to work well with modern Shimano freewheels (both 14-34 megarange and 14-28 normal sorta thing) and KMC 8-speed chains. It's just like any other index system, you get the hanger straight and use only derailleurs that were designed to work with the matching shifters. I've used some shifters that will have three settings: UL, for index shifting with SunTour's narrow-spaced Ultra-7 freewheel; F, for friction shifting; and RE (regular), for index shifting with most standard-spaced 5- or 6-speed freewheels. The UL setting is the one for 7-speed freewheels of all kinds, because all 7-speed freewheels are "ultra" spaced. The ones I've used have an extra click and I've wondered about taking them to 8-speed, but I've never had the free time to try.

thook

good gawd...lol! i'll pour over it more while nothing's happening at work tomorrow. thanks!

thook

i do, but we'll see. after having read about 1/4 of the page in the link from yellow jersey, my enthusiasm for suntour has wained a tad. the technicalities seem a little daunting right now. but, rebuilding engines did at first, too.

if i do go through with it, the freewheels are barely worn

thook

well, 7spd is as far up as i'm gonna go with gearing. and since i have these two AP freewheels, i just thought it might be fun to take advantage of the suntour indexing. my mention of 8spd's is in reference to the shimano thumbies capability only

thook

would you mind clarifying? are you trying to say avoid getting shifters that have both as options? iow's, stick with shifters that index only?

ps. i should mention i have atleast one shimano 9spd chain. so, that's good

thook

i've replied in red. hope that works well enough

thanks all!!

dddd

I don't know about "powershift", but the later freewheels with modern cog tooth features were branded PowerFlow, which helped indexing, though the freewheel bodies seemed to be made to much lower quality standards than the previous Alpha freewheels (I believe that by this time, production had moved to a different factory, in Taiwan instead of Japan).

The gear oil would work fine, maybe not for many long years like internal greasing, but add ten drops every couple of years and I would expect top performance. Let it drain in the hot sun on a cloth or cardboard strip for a day or two after you initial soaking, better than having oil drain out onto your hub and spokes.

On Accushift shifters having a selector for "F7, friction light index", don't use this setting or you'll be disappointed. It would only be good possibly if your components were somewhat index-incompatible imo (I've tried it on a couple of bikes and it sucked in other words).

Using narrower-than-indicated chain with Accushift levers will prevent the chain from momentarily over-shifting to the next-larger rear cog than you are shifting too. Accushift levers featured ample "over-shift" movement (freeplay between the lever/spool and the indexing ring), which was to make up for the lack of advanced shifting enhancements of 1980's chains.
Shimano's 9sp chain is sufficiently narrow for Accu-7 spacing and features the measurably best ratio of any 9s chain in terms of bulged sideplate width versus pin width, so is ideal for use with Accu-7 setups.
Similarly, earlier 6sp Accushift setups work best with most any modern 7-8s chain.
Suntour would have done much better with their indexing efforts if only they had the sort of chains then that are available now.

clubman 

You weren't technically wrong about the 3 Pulley Cyclone. I sold one NOS last year, in the sealed bag and clearly labelled RD 3000

masi61

Your AP freewheel (7 speed) should work well with the X-1 rear derailleur. You should use compatible 7 speed accushift levers. On my touring bike I have a Winner Pro 7 speed touring ratio freewheel, an X-1 rear derailleur (I bought this NOS from Yellow Jersey for $55), and Superbe Pro index down tube braze-on levers. The front shifter is friction to an older Specialized road triple crank paired with a SunTour XCD rear derailleur. I’d have to look to see what chain is on there (I have multiple road bikes and I haven’t ridden this one in several years.

The shifting for this 3 x 7 combo is very good. Excellent actually. Different than Shimano I think since the clicks are a bit more positive (less soft) compared with Shimano.

Keep in mind that the AP freewheel has different spacing on the smaller cogs compared to the larger cogs. Sorry, the exact specification doesn’t come readily to mind, maybe the archived PDF file from Yellow Jersey lists it. I want to say that the bottom 3 cogs are like 2.8mm spacing, the remaining ones are 3.0mm spacing. It has to do with the sweep of the rear derailleur as it responds to the cable pull of the shift lever.

To the person who mixes and matches Shimano with the SunTour, I would say more power to you but I believe best performance comes from matching parts. People that get these mongrel systems to index sufficiently I believe are relying on Shimano’s patented floating upper pulley “Centeron” in order to approximate proper shift spacing. Better to use all matching parts, I think.

I also run a he SunTour Accushift 8 speed Superbe Pro cassette hub with command shifters in a 3 x 8 configuration which I cobbled together custom and it is equally awesome. Since 8 speed accushift cassettes that are not “Microshift” (with the outer 2 cogs threaded together as a sub-assembly) are about as rare as a white Unicorn, I had to merge an extra cog and spacer from a spare 7 speed AP-II cassette. It turned out fine and uses the same tighter cog spacing on the smaller cogs compared to the bigger cogs.

The quality level of the Superbe Pro cassette hub is comparable to Dura Ace 7400. Very heavy but lifetime durable. My freehub body got gummy and the chain would go slack when coasting so I drizzled a few drops of Pedro’s Synth Oil in there and it freed up almost right away and all is well now.

If you are unable to source the Command shifters and only able to locate the down tube levers but desire a handlebar mount there are still options. While I’m not sure about putting them onto bar end shifter pods (I think SRAM might make a set), Gevenalle sells there Audax brake levers that have braze-on mounts. These are not cheap @ $160, but represent a decent value since they are high quality.

Let it us know how you move forward with your project and if we can be of more assistance.

pastorbobnlnh 

IMO, the best way to service a freewheel is to service it like any other set of bearings and races: Disassemble, clean, lube with grease, reassemble.

A freewheel is not a secondary cut of beef which benefits from an overnight soak in the marinade. A freewheel is not the Thanksgiving Turkey which enjoys basting.

Would you squirt some magic elixir into your headset or bottom bracket and expect it to be magically healed from all internal contamination? Would you figure out some way to soak your entire wheel in a vat of witches' brew made from some esoteric automotive mix of ingredients in order to service the hub's bearings?

Please treat your vintage freewheel with respect and service it properly.

canklecat

I don't think I've used any Accushift Plus+ components. But my '89 Ironman came with the Suntour GPX group. It is picky, as Suntour's own tech manual advises. But not impossible to set up satisfactorily.

I got the best shifting with a SunRace 7-speed 13-25 chromed MFR30 freewheel, combined with a KMC Z72 chain. Snick-snick from the downtube shifter, no clunking sounds from the rear derailleur, no slight rattly sound from the chain.

Once the right components were in place, index shifting with the GPX group was a delight. No need to finesse anything, such as slightly over-shifting in certain cogs to be sure it connected.

I also replaced the original plain Suntour 52/42 chainrings with Vuelta. The 39T small ring is plain, but the 50T big ring is ramped and pinned, and shifts much more smoothly than the original Suntour 52T. No more dropped chains or hesitant shifts on climbs.

In comparison, the original Suntour Alpha 7-speed 13-24 and my recent replacement 13-26 freewheels are picky. They lack the fancypants tooth shapes of the SunRace, which was borrowed/stolen from Shimano's designed. The Suntour freewheels do not like the fancy KMC chains like the Z72 and Z50, with shaped, beveled/chamfered side plates. Those chains invariably cause slight rattling in the middle cogs as the Suntour freewheel wants to grab the chain and shift no matter how much I fiddle with drivetrain adjustments. The Suntour prefers plain sideplate narrow chains, so for now I'm using a KMC Z33.

I'm gonna try @dddd's suggestion to try a Shimano 9-speed chain. But for now the Suntour 13-26 is behaving acceptably with a KMC Z33 that I already had -- it was slightly used with another bike/freewheel, so it's probably not an ideal example of what to expect from a plain KMC narrow chain.

No idea if any of this applies to the Accushift Plus components.

thook

yeah, i just don't have part of an afternoon right now to take apart these freewheels that have likely never been apart since they were manufactured. you know how it is; maaaayyybe they will come apart fairly easy.....maaaayyybe they won't! iow's, i know a proper cleaning and greasing is ideal, but i'm confident nothing will die if i band aid them for the moment. plus, i either need to buy or make another chain whip to do it

i'll keep your F7 recommendation in mind! thanks

while i've yet to finish reading the yellow jersey link provided above, i have read far enough to be familiar with the mention and nature of the "over-shift" feature. the use of a 9spd chain makes sense, then

thook

********** i never mentioned anything about a 3 pulley cyclone. i don't have one nor am i looking to get one. what i have is what's shown in the image i linked. you got me a little puzzled, man

clubman 

Doh, sorry. I looked at that Cyclone ad and saw 3 pulleys. And as the fog lifts, I think the 3 pulley Cyclone was a 6200. Fading memories.

The Golden Boy 

From my experience: Accushift 6 speed is easy- use Accushift shifters with Accushift (or Accushift Plus) derailleurs and either an Accushift or Shimano or SunRace or (...) 6 speed freewheel and magic happens. I've used the Shimano 6-7-8 chain, the KMC chain and SRAM PC 870 and 850 chains.

After 6 speed, we go into weird territory. Some people have experienced all kinds of different things- Suntour shifters working with Shimano derailleurs and Shimano cassettes...

I just know that I've had trouble with every combination of 7 speed Accushift and Shimano shifter/derailleur + Shimano freewheel that I've played with. I'm inclined to let people play with it- I would *guess* that if you use new housing (not NOS "new"- but new, quality housing) your success rate will be higher.

As an aside- someone posted an ad (Yeti?) that had XC Pro thumb shifters as an option to use with M900 XTR derailleurs.

As far as shifters... I've got 2 sets of Command Shifters running 6 speed Accushift derailleurs (I think both are XC Comp right now) Shimano freewheels. I also have a set of Command Shifters that I've set up for 10 speed- but that's a whole 'nother thing. Yes- the front shifter on Command Shifters are ultra-fine ratcheted- it's more fine than the old Power Shifters style of ratcheting.

Here's my Trek 400 Elance- (I lied, it's XC Pro.)


1986 Trek 400 Elance by Dave The Golden Boy, on Flickr


1986 Trek 400 Elance by Dave The Golden Boy, on Flickr


Here's my Trek 620 (this one has XC Comp and Bullseye pulleys):


1985 Trek 620 by Dave The Golden Boy, on Flickr


1985 Trek 620 by Dave The Golden Boy, on Flickr

thook

thank you for sharing your experience.

re: gevenalle....yeah, for that price i could just get some NOS AP barcon shifters on ebay....which is way out of my price range. i just wouldn't even do it even if i had that kinda money, though. it's a bike... not a ferrari...lol

i remember, now, about the cog spacing. thanks!

thook

duly noted.....

thook

fair enough....and thank you for the input. i had thought of simply getting a hyperglide freewheel and calling it good, but the purest part of me was begging for a compromise; stick with the suntour freewheels and give the AP shifting a try though likely a hyperglide freewheel/shimano barcons would be superior in function. i mean, ultimately function is the name of the game, but since my recent univega was a gift and so beautifully vintage i want to try and keep the build of it as close to the era as possible.

thook

lol.....tricky human brains, eh?