ehcoplex

I've got a couple Suntour 6sp freewheels in my parts bin I'd like to get apart so I can (hopefully..) do some cog swapping. I can't find anything that indicates what the models are- to my eye they look the same, but maybe not. Can any experts tell (& tell me if the cogs are likely to be interchangeable)?
I'm also having a bear of a time getting the second cogs off both of them- the smallest were tough, but I got 'em off. Is there any trick or idiosyncrasy with the second & third cogs on these? Or is it just about brute force...?
Thx



(I thought the one on the left had gold cogs- turns out its just yellowed grease....!)

pastorbobnlnh 

Both are the a New Winner model and the four smaller sprockets thread off with normal threads (lefty loosey). Soak theeads with penetrating oil and use heat if stubborn.

The two largest sprockets are splined and slip off. Keep us posted.

52telecaster

Thanks man. I've only ever removed the outside cog. Cool to know how it works.

oneclick 

Stubborn sprockets need either two whips with long handles or one and a sprocket-vise.
I lke the second method better because
a) you only have to control (direction) one tool; and
b) you can use both arms on the same tool, which gives you a different form of better control - force modulation.

A sprocket vise is easy to improvise if you have a normal bench vise.
Get four big pan-head screws and fix the freewheel to a block of wood, each screw in a tooth-valley of the outer-most sprocket.
Tighten the bench vise like you mean it, the tighter the jaws the better the scews will grip.

John Nolan 

NIce tip on the sprocket vise.

Velo Mule

Here is what I had used:

It is a piece of pine. Usually I would select pine for projects that are straight grained, however for this I thought that that knot might actually have some benefit.



I have holes for the two sizes that I had worked on. 28 and 30 teeth. There is a block screwed and glued underneath to engage into the vise or in this case a Workmate.

Here it is with a Regina Freewheel:




This is not the sturdiest kit. It is still possible to put so much force into getting your cogs off that the wood splits. So far, this has held up, but those screw holes will open up and the screws will bend with each time that I use this wooden cog vise. I would love to make this out of aluminum or better yet steel, but I haven't needed to do that yet. I'll probably wait until I break this one and go flying into a tool box or the floor before making a better version. I've broken some chain whips in this process too.

I like taking the cogs off not only to mix and match them into a custom freewheel but sometimes just to clean them up really well. I can get a bit fanatical and I like my old freewheels.

ehcoplex

I’d been going at them with 2 whips, which can sure be awkward. The wood/screws/vise setup looks just the ticket. Alas, no suitable bench vise, but I think I can attach the setup to something… As far as the heat application, pastorbobnlnh , do you mean localized with a torch, or the whole thing in the oven for a while?

3alarmer 

.
...I use the 50/50 mix of acetone and ATF as the penetrant for freewheel disassembly, a MAPP gas torch, and one of the old commercially made Bicycle Research freewheel vise things, along with the biggest, most brutal chain whip I could find, the one from Park Tool. Even with all of this, they are often very difficult to disassemble.

ehcoplex

Not elegant, but it did the trick and I didn’t have to venture out to the freezing cold work shed and rummage around for anything! I’ll build myself something better when it’s warm again…

PhilFo 

One of these days I’m going to make myself a copy of the Bicycle Research freewheel vise. It is a block of aluminum with a cylinder sticking out of the top that the freewheel rests on. There is an a 8” length of chain attached which wraps around the cog closest to the main block. All this sits in a bench vise and makes freewheel repairs a cinch, all you need is a long chain whip. It wouldn’t be hard to reproduce this either by having the whole thing machined or just by cobbling some bits together. I think I rebuilt a few thousand Suntour, Atom and Regina freewheels using one of these tools, over the years. I did 120 alone in a few weeks at the last bike shop I worked at. Just blew through a few hundred pounds of freewheels, yanked old cogs off, replaced with new (spaced for Shimano) and either set them up on used bikes for sale or sold them for repairs.
The Suntour New Winner and Winner Pro freewheels were, in my opinion, the pinnacle of modular, customizable gearing. They could be respaced to work perfectly with any manufacturer’s indexing, granted, you can’t go past 7 cogs. The few 8 speed freewheels out there required too much space and only a couple high end hub manufacturers, had axles that wouldn’t bend.

oneclick 

Three basic principles of heavy hand-tool work:
a) get something else to hold the part
b) get a longer/bigger lever
c) quick-and-done is better than slow-and-done.

ehcoplex

All apart and cleaned up. Of course I thought 'I'll keep 'em all in order and remember which spacer goes where......', but in the process of moving them around, cleaning, etc, now I can't... I'll assume I can find a diagram, or the knowledge-base here can help me out when I put these back together. Anyone know what the available tooth-count/ranges were for the screw-on and slip-on cogs? I'll have to spend some time with the gear calc to figure out what's going where (or what cog(s) I need to acquire)..
Interesting to note that the 'bottom' of the freewheel mechanisms are slightly different from each other..
Also interesting how these just feel 'high quality'- certainly compared to the IRD freewheel I've got apart to do some cog swapping. The cogs on the IRD just feel cheap & flimsy next to the Suntour.

Mr. Spadoni 

Do a search for Suntour Freewheel chart on the google and there is an image from Yellow Jersey that is of the original chart that shops would use for cogs and spacers. Also Sheldon Brown has an article that gives descriptions of the cogs and spacers with measurements which is helpful if like me, you can’t keep the parts in order.

pastorbobnlnh 

Suntour six-speed freewheels came as either standard or Ultra (narrow) spaced. So either for 120mm or 126mm rear spacing. Do you have any idea about the spacing of the bikes these two came off?

If the spacing is the same between all sprockets it is a standard spaced model. If there's a slight difference between the 2nd, 3rd and 4th, the spacing is narrow.

IIRC, the largest threaded sprocket would be a 24T.

ehcoplex

I think one was on a 120 and the other on a 126..... One of them did have a rather thick spacer (center left in the above photo..) that I sort of recall was behind the largest cog, but I might be mis-remembering that..... In any case, either/both are likely to be used on 126mm spaced bikes.

mountaindave 

Of course this is now hindsight, but I like to put all the sprockets and spacers in order in a zip tie or bent spoke or whatever, so I don’t mess things up. Works well for headset jobs too.

The large number of varying spacers, often doubled up, on SunTour FWs can be daunting. But the Ultra spaced 6 speed FWs are pretty handy on 120 spaced hubs. And their indexing capability with Shimano SIS can be a nice bonus.

PhilFo 

Biggest cog for the Winner / New Winner system is 32 teeth, smallest is 12. Same spread for the Winner-Pro but five of the cogs are splined instead of two. The spacers which really need attention are the beveled ones, as they have the bevel so as to not disturb the chain rolling on the next smallest cog which the spacer is supporting.
To get your mixed up spacers and shims back in order, just slip them over the freewheel body. If it fits over the splined portion, you know the spacer/shim fit between the largest two cogs. The other spacers/shims will fit between the threaded cogs. When reassembling, put your shim on the large cog side of the spacer in your standard spaced freewheel so it's not affected by tightening the small cog. Those shims are very thin steel foil which crease and break easily. If you get a crease in the shim, you could develop a creak in your drivetrain; same goes for a cracked shim.
If you want to really treat the freewheel to a spa day, flush it out using whatever degreaser you prefer, then lube it. Don't dismantle the freewheel body if you want to use it, no need to do that The freewheels are sealed better on the dropout side, so you'll want to flush with the hub side down. Once you get it really clean, you should hear nice sharp ticks of the pawls and a bit of rolling from the bearings. No scraping should be heard. If you hear scraping or feel binding after your cleaning, you may have a broken pawl spring which was staying quiet from 50-year-old hardened lube. Don't use this freewheel. I think I've only seen or heard broken springs a few times, and those were all on visibly rusty freewheels. Anyway, once this is all clean, wick in some good sticky lube oil, like Phil's Tenacious Oil or hypoid gear lube. Spend a while turning the freewheel, while dribbling the oil in from the dropout-side. Make sure the oil reaches the hub side bearings. It's easier to lube from the hub side as the freewheel bearings are often visible and the gap larger; the only reason I mentioned lubing from the other side is to prevent any old crap from being redeposited back into the body. Since the body is better sealed on the dropout side, it's harder for stuff to come out over there. Realistically, you may have to add oil to both sides. Regardless, a New Winner freewheel is really one of the best drive parts ever made.

pastorbobnlnh 

I don't want to be a disagreeable old fart, but the advice offered above on servicing a vintage freewheel is a temporary solution at best. We'd never service our hubs, bottom brackets, or headsets in such a fashion. Even the jockey wheel and pulley on a rear derailleur are disassembled, cleaned appropriately, and reassembled with grease.

Granted, servicing a freewheel correctly is easier with specific tools, but the same applies to our BB and hubs (for instance, cone wrenches). Yet, with the exception of the Suntour New Winner and its adjustable outer bearing race, no special tools are needed except the specific freewheel removal tool and chain whip(s), if the sprockets need to be removed.

I'm traveling at the moment and replying from my phone, which is slow and tedious for this old fart. When I can access my PC I'll outline the steps with pictures. I contend it takes less time to correctly service a freewheel than to subject it to the flush and dribble mess.

oneclick 

A few minutes with a small grinder will make one of the Perfect-series 34t or 38t fit.

steelbikeguy

Your first post appeared to show a New Winner freewheel. It should say "Patent NWN" if it is. Here's a photo of one of mine...



SunTour had a little brochure that discussed the different configurations of the cogs in order to make 5, 6, or 7 speed freewheels. There was the option of "normal" spaced 5 or 6 speed freewheels, or "ultra" 6 or 7 speed freewheels. The "ultra" version used a narrower spacing between cogs, which is achieved by using thinner spacers. Here are two pages from that brochure:


high resolution version


high resolution version

Shops used to sell spare cogs, spacers, and bodies. They used a board with hooks to organize the parts, as well as to organize and explain them. Pretty clever, really! It also makes a great reference piece for hobbyists.

high resolution version

details on the spacers are at the bottom. Note that they are grouped by whether they are "normal" or "ultra" spacing. Also note that the bottom portion shows what spacers are used, and that a given configuration might use different spacers in a particular position, depending on what the cog sizes are. In some cases, it's harder to find the right spacer than the right cog.

high resolution version

and if you haven't already noticed, most cogs are marked with a code that indicates what type of cog it is, as well as the number of teeth. For instance "R20" indicates that it is a threaded cog that goes in the middle of the body, with a flange, and has teeth that are beveled on just one side.

Steve in Peoria

ehcoplex

Follow up/vent, or sorts.. I really need to sort out one of these Suntour freewheels (need to source a couple cogs) to replace the IRD I've got on the bike. Bought the IRD quite a while back, and had to buy a couple additional IRD cogs to get the ratios I wanted, but....... I'm really disappointed in it. Less than 50 miles on it and lots of play and a kind of grinding sound at certain points in the 'freewheeling' rotation. Yeah, should've paid more attention to the negative reviews online. And I'll add that their customer service was really vague and kinda ****** back when I inquired about some details about the cogs. Expensive lesson learned. Now to find the necessary cogs for the Suntour..... ah, more $$......

gkamieneski

I had thought the Winner FWs used a 4 notch tool, or was that when they went to Winner Pros?

jalwlb

IIRC the Winner and Winner Pro FW's do use a 4 notch tool. The New Winner FW like the one pictured above uses a 2 notch tool.

dddd

Removing stuck cogs is like removing a stuck crank bolt cover.

Take a sturdy drift like 5/16" diameter, or similar strong bolt perhaps (held with a locking plier).
Get a big hammer and lay the freewheel down on a smooth concrete surface.
Strike the frozen cog next to the outer periphery of the threaded body at several points around the body.

Cog should now unwind using a lot less torque than before.
I sometimes get final loosening result after repositioning the chain whip a few times.

To determine cog spacing, I place a 1/8" or 3mm Allen key between two of the larger cogs. Narrow spaced Ultra (or 7s) won't allow the key to turn.

oneclick 

Screw the block to a *length* of 2x4, and use that as one "whip", and your bestest longest whip on the sprocket you wish to remove.