acorn_user

Hi all,
some of you may have seen my post in the cross forum about converting my Dawes in a cross bike.

I'm planning on using Suntour command shifters to do this. They are marked "accushift plus" and are 7 speed (friction front).

I also have a scratched but nice XC Pro rear mech. It also says accushift plus, but there is no obvious model number.

The reason I ask is that I'm not sure whether I'm going to be able to use these in conjunction with a Shimano 7 speed cassette and keep indexing. I'm happy to rely on friction, but I keep seeing XC Pro rear hubs on fleabay. Which kind am I looking for? Can I run Powerflo, Microlite or Microdrive? Or should I wait for a freewheel one?

Failing that, can you use spacers on HG cassettes?

Thanks very much!
David

mrmw

I do it, and it works perfectly, unbelievably perfectly. My Setup:
--Suntour Command Shifters, seven speed indexed
--Suntour XC Comp long cage rear derailleur
--Suntour Accushift rear derailleur cable housing
--Shimano XT six of eight cassette, custom spaced plus one custom cog, 13-14-16-18-21-24-28.

Detail:
1. Start with a Shimano HG Eight speed cassette. Either a model HG-70 (good because its bolted together, not riveted together like an HG50), or a Deore XT eight speed cassette--whose largest five cogs are riveted onto a lightweight carrier but whose 3 smallest cogs are 'free'. (I started with an 11-12-14-16-18-21-24-28 XT eight speed cassette, see bullet {3}, below for the how-to).

2. Dense and Granular Theory:
--Where you want to wind up is with center to center spacing of 5.3mm between cogs 1 and 2 and cogs 2 and 3 (the physically smaller end of the cassette), and spacings of 4.8mm between the larger end of the cassette for cogs 3 to 7.
--SheldonBrown.com teaches that Suntour 7 speed cog width (all cogs)=2 mm, with center to center spacing of 5.0 mm and 4.8 mm, first and second position spacer width=3.0mm and third through seventh position spacers=2.8mm.
--In contrast to sheldonbrown.com, the rosetta stone link below teaches that Suntour Accushift first and second position spacers are 3.3 mm and first and second position center to center spacing is 5.3mm; and confirms the sheldonbrown.com taught 4.8mm third through seventh position center to center spacing.
--SheldonBrown.com teaches that eight speed Shimano HG cassette cogs are 1.8 mm thick and has spacers=3.0mm; and that 9 speed Shimano HG spacers are 2.56mm.
--Our target custom spacing is 5.3 mm between cogs 1 and 2 and cogs 2 and 3 to work with a Suntour Accushift 7 speed shifter coupled with a Suntour Accushift rear derailleur.
--0.5*1.8mm/cog *2cogs +2.56mm+1mm =5.36mm. Six hundredths of a millimeter off is well within smooth index tolerance.

3. Practice:
This is actually pretty easy. Plug and chug.
--From your Shimano HG eight speed cassette, lose two cogs, the two smallest, since one or both incorporate built in spacers which will fubar (f__k up beyond all relief) the custom spacing.
--Now you have six cogs left.
--Add one cog, a new smallest cog. Now you have seven cogs.
--for your new cog, use either an 8 speed cog(1.8mm) or a 9 speed cog (1.78mm) . If you use 9 spd cog, you will have a slightly improved first position spacing of 5.35mm (only five hundredths of a mm out of spec).
--To space the cassette's physically smaller end between cog 1 and 2 and cog 2 and 3, use a custom spacer set consisting of a 9 speed spacer (2.56mm) plus a 1mm spacer.
--If a 9 speed first position cog with built in spacer is used, then all you have to add between cog 1 and 2 is a 1mm spacer; and use the 2.56mm + 1mm spacers between cogs 2 and 3.
--the remainder of the eight speed cassette is center to center factory spaced at 4.8mm .

Sheldon Brown teaches that suntour Accushift seven speed spacing is 5mm and 4.8mm at ths link:
https://www.sheldonbrown.com/cribsheet-spacig.html

I tried that, and it worked, but it was clunky.

Subsequently I found this link, and it was the rosetta stone:
https://cgi.ebay.com/New-Old-Stock-Su...QQcmdZViewItem

Because its an ebay listing, and will go away, attached is the picture showing the second position 7 speed Suntour Accushift spacer marked 3.3mm, and here is an excerpt:
"Here is a set of five (5) black plastic spacers for a Suntour Accushift Plus (AP) cassette. This offering includes four (4) spacers that measure 2.8 mm thick and one marked spacer that measures 3.3 mm thick. Based on the complete Suntour AP cassettes we have in stock, as well as from doing some catalog research, it appears these spacers should (in most cases) properly "space" the six (6) tallest sprockets in a 7 or 8 speed Accushift Plus cassette (and this would appear to include most AP II or Powerflo models).

Research on selected trusted websites does yield slightly different specs. on the spacing of Suntour's AP cassettes (7 and 8 speed models), but the differences are fairly mininmal. Most of our research indicates the tallest sprockets should be separated with 2.8 mm spacers, but there seems to be some difference of opinion when it comes to the smaller sprockets. According to selected website references, the consensus spacer width for the smaller sprockets appears to vary between 3.0 mm and 3.2 mm...and then there is a Suntour pamphlet that we have that specifies the width of the second position spacer (between the second and third sprockets on a 7-speed cassette) to be 3.3 mm. This same Suntour brochure also specifies the larger sprockets (the largest 5 to be specific) should be separated by 2.8 mm spacers, which is fairly consistent with our other research). So again, the only real differences here concern the smaller sprockets.

As a result of the slight variations noted above concerning spacer width, we decided to build/mount some AP cassettes from some spare parts we have available. The results were fairly conclusive as follows...using the five (5) spacers offered in this listing, we were able to build a 7-speed cassette by pulling all of the sprockets from one of our 7-speed Suntour cassette offerings (including the smallest threaded sprocket with a built-in spacer) and build a 7-speed cassette that mounted on a Suntour 7-speed AP freehub without any problems. We also noted the stack height of the cassette we built was extremely close (with 1/10 of a mm) to the stack height of this other 7-speed Suntour cassette offering.

We did the same with one of our 8-speed Micro-Drive cassettes, and using the two sprocket (connected) lockring that comes with our 8-speed Micro-Drive cassette offerings, we were able to mount our make shift cassette on an 8-speed Micro-Drive freehub without any problems (meaning the lockring threaded fine and cinched down on the cassette, as spaced by the spacers offered in this listing). Keep in mind though, for the 8-speed Micro-Drive setup, the two sprocket lockring does include two built-in spacers."

One more thing: The Suntour Accushift Tech manual posted at yellowjersey.org teaches that center to center spacing of the rear derailleur mounting bolt and the rear axle should be between 24 and 28mm.

I measured several Shimano SIS setups and they met this spec.

I'm running about 34 mm. If I slide the wheel forward 3/4" in the dropouts to reduce the rd/axle spacing to about 31mm, I get an ever so slight improvement in smoothness. Frankly, though, nowhere enough to justify the change in geometry.

And finally: I noticed a marked overall improvement in rd indexing precision and smoothness after I flushed the heck out of the rd with Tri-Flo spray lubricant. I had already cleaned and lubricated the rd before installing it, but after a particularly intense pollen season here in Atlanta this past spring, both front and rear der's were 'scratchy' whenever moved/pivoted. The Tri-Flow flush truly produced wonders. Its now part of my 1500 mile chain swap maintenance. Also, as the LBS taught me, I use teflon tubing under the bottom bracket to smooth cable movement and eliminate friction. They said they routinely do this on all indexed bikes when they work on them.

OrangeOkie

mrmw . . . looks like you hit the mother lode of info. Thanks for posting this.

acorn_user

Certainly looks like it. I am glad to see Orange Okie reply too

I think I have worked worked out the hubs too.
Microdrive chainrings are smaller, so you need smaller cogs in order to get a sensible gearing range. In order to make an 11t cog fit the hub, the made a section of the hub smaller. So Microdrive (i.e. 11t) hubs and cassettes, whilst not using unique spacing, do use unique cogsets and are not compatible with others.

Is that right? I'm sorely tempted to get an XC Pro rear hub for the time being. They are so pretty, and grease guard looks like a great plan for cross and commuting.

Thanks for all the input so far!

cudak888 

mrmw, I can't seem to figure out what you're using for the last cog - are you just using the lockring pressed against a pair of spacers? I'm a tad confused. Do you have a photo of the setup?

I might try doing this with a Shimano UG setup, if I can grind down the spacing on the threaded cogs sufficiently.

-Kurt

mrmw

Attached in the first figure is the schematic.

Attachment 2 & 3 are pix.

Shimano HG six of eight plus custom cog schematic, see figure, attached.
1. Lockring sized for the first cog, then
2. Very thin washer, hand scored with a flat blade screwdriver so it grips the lockring (or, just use a 9 speed first position cog and omit the washer)
3. first position 9 spd custom cog
4. 9 speed 2.56mm spacer (omit if custom 9 spd cog used has built in spacer) + 1mm spacer
6. 8 speed second position cog
7. 9 speed 2.56mm spacer + 1mm spacer
8. 8 speed third position cog
9. 8 speed 3.0mm spacer
10. ibid i.e. (8) and (9) up to and including the seventh and largest cog.

Host bike is a 1982 Schwinn Super Sport S/P. Front is 48/38/28 on the original Sugino AT crank and with the original Suntour Cylone MII front derailleur. Rear wheel is 105 hub 126mm OLD with Mavic A719 rim and 700x35mm tires. Top wind at my back gear is 102 gear inches, 90% of riding is on middle chainring across all seven rear cogs, gear range from about 37 to 87 gear inches. I like this so much its killed off almost all my covetous bike lust. OK, I have a line on a 63cm NOS Bob Jackson frame, I'm still interested in that one, and ever, a touring Paramount. And boy, all those chrome bikes are so pretty...

But really. The thing that was most important was to report the spacing rosetta stone and actual field test, so we who hate black box don't mess with innards' brifters can have the updated info in the permanent record.

Sincerely,
Steve (I've read every page at Sheldonbrown.com nine times, doh, because I learn something new every time) D.
Atlanta

acorn_user

Got this reply from the NOS Shop types...

Hello Dave...never thought of this. The Suntour Accushift and Shimano HG cogs are about the same width (if anything, the Suntour cogs might be a little wider...but no more than 0.1 mm...so probably within a tolerable range). The spacer widths are bound to be different...as these five Suntour spacers have a total width of 14.5 mm and 5 Shimano 7-speed spacers will have a total width of 15.5 mm (5 x 3.1 mm) and an 8-speed will have a total width of 15.0 mm (5 x 3.0 mm). Now if the Suntour cogs truly are a bit wider, then you might have a chance at making this work. Also, the Suntour spacers themselves will slide over a HyperGlide freehub, but they are a little big...so not a snug fit...but if the spacing works out and you can get your standard HG lockring to cinch down on your HG cogs with the Suntour spacers, then not sure the slighlty larger spacers would be a problem...as they would be locked into place. I guess my only real concern here is if the total spacing ends up being a little short...then that lockring may not be able to cinch down on your mix-n-match cassette. If this were the case, then I guess you could replace just one of the 2.8 mm spacers with one of your wider HG spacers...and that might be enough to do the trick...and hopefully still maintain functional Accushift shifting (although you might have to play with it a bit...to see what position works the best with a slightly wider spacer). Sorry for the long note...just trying to think through this to see if it might work for you...although we are not for sure...as we have never tried this ourselves...but hopefully some of our notes/thoughts help you out. Thanks for the interest. Scott

Might give this a go

Ranman

mrmw - great thread.

Are you running a 7 speed chain with this setup?

mrmw

Yes. Sram PC-58. They look to be lasting 1500 miles or so under my 240 pounds all in dry asphalted road conditions. I clean/relube about every 400 miles.

acorn_user

I wrote to Welsh engineering types Highpath Engineering. They can supply spacer sets for 18 pounds. So if the ebay source runs out, there is another! I will post more details after I speak to them again. It looks like all those Suntour bikes can be kept going after all

mrmw

I'm not sure where you are heading, however, a Shimano cassette will not fit over a Suntour cassette hub. Nor will a Suntour cassette fit over a Shimano cassette hub. They are splined differently, and they attach and secure very very differently.

My responses up thread are in the context of using a Shimano Hyperglide cassette hub and Shimano Hyperglide custom spaced 7 cog cassette with a Suntour Accushift rear derailleur combined with Suntour Accushift 7 spd shifters.

Just an fyi in case your were heading out into the fourth dimension without a tie back...

acorn_user

Wasn't heading in that direction. My question was about which Suntour cassettes fit which Suntour hubs, and whether it's possible to use Shimano HG cassettes with spacers on Shimano hubs to get indexing. I was worried about investing too much in a system with limited spares and using Shimano bits solves that!

curtisfong

Bump! I found an easier solution if anyone is still interested in this topic. Since Shimano 8sp spacing is 0.5mm less than Suntour on the 2 highest gears, I added two 0.5mm spacers (for cassettes or bottom brackets, mine was listed as a BB spacer) and it works great. Shimano 7 speed spacing is slightly different than 8, so if you want to run 7 speeds, buy an 8 speed cluster but leave off 1 of the gears. I'm using this with 7/8 speed Superbe Pro levers and an accushift superbe pro derailleur; 8sp cassettes from SRAM or Shimano are very cheap; so are the chains. Shifts are much better with this setup vs. a 12-26 winner pro freewheel.