pastorbobnlnh 

Jon,

They all appear to be facing in the same direction to me, beveled tooth side out. Which all the threaded cogs do. I've always wondered if it matters, as long as you are consistent when adding the cogs to the body.

Sometime last year this thread inspired me as I stumbled across a 38T Perfect/ProComp cog on ebay. Below is my rendition of the really low geared freewheel. I built it around a very nice ProComp six speed body (and IIRC is standard not Ultra spaced). In my case I kept the first five gears closer together with a larger 8T jump for the final bailout. 15-18-21-26-30-38.



My plan is to mount this to my Campagnolo equipped '62 Schwinn Continental with the long cage Gran Sport RD that our C&V member Henry III customized, mount a set of 27 X 1 & 3/8 knobbies, and take it light trail riding, aka vintage cyclocross.

jimmuller 

Why the 21 to 26 jump? A 25 instead of 26 in that spot would give much more consistent intervals.

pastorbobnlnh 

Jim, great idea and suggestion. I always appreciate advise from my "gear head" engineering buddies. IIRC, I do have a 25T Perfect cog and will give that a try. I'll keep you posted.

Tom the tank

Here is my "new" Suntour Perfect AG. The cogs are 14.17.20.24.28.34. I have a 38t cog on the way, but is spins so nicely I am hesitant to start tearing apart the freewheel. As is, with the 52/42 chainrings up front, I will get the following gears:

100.9 81.5
83.1 67.1
70.6 57.1
58.9 47.5
50.5 40.8
41.6 33.6

The 38t would result in a modestly lower gear.

37.2 30.0

I'm unsure which cog I would sacrifice to swap in the 38t. All the middle gears seem pretty useful. I could build it up like a Shimano MegaRange, with a 10t jump bail out gear between 28 and 38. Or I could drop the highest gear. As I'm planning to use only five speeds the 14t will likely not be used, other than as a lockring. If I do that I'll get 70.6 to 30.0 gear inches using the 20.24.28.34.38 teeth. Rather pedestrian, but decent cruising gears, and climbing gears for mountainous Montreal.

Any opinions or advice?

pastorbobnlnh 

Tom,

The top two cogs (in your case the 14T & 17T) are threaded and once removed the other cogs slip off splines on the freewheel body. None of this affects the internal workings of your freewheel, so don't worry about removing them.

One option would be to replace the 24T and 28T with 26T and 30T. I have those but probably not in silver.

Tom the tank

Hmmm. My 5 speed suntour had the exact same 14-28 cogs. I'll see if I can source the 26 and 30 locally before I hit you up Pastor Bob. I think I'll try the 14-34 and see how I like it. In the meantime, I'll mess around with the 5 speed for practice. Thanks for the advice.

pastorbobnlnh 

Tom,

I meant to respond to this last night as well: Unfortunately with the Suntour Perfect/ProComp freewheel body, you can't do this because the first two cogs are threaded. In theory you could if a 20T threaded cog was available. The largest threaded I've seen is the 18T, and I've only ever had a few of these. Even finding a first position 15T threaded cog for the first one on my 15-38 was a rare bird. I would have liked to have started with the 18T cog and then tried to have nice even spaces between the 20 tooth range to the 38T. Something like 18-21-24-28-34-38.

In many respects the Suntour Perfect/ProComp had to have been one of the simpler yet most customizable 5 & 6 speed freewheel systems back in the '70s. But there were still limitations. The Suntour Winner family of freewheels took customization to a higher level, but at the cost of extreme complexity.

What I'd love to invent is a series of freewheel bodies with spacers that allow us to cannibalize modern Shimano/SRAM/Sunrace, etc., cassettes and custom build our own 5, 6, and 7 speed freewheels. Two or three different body widths and the appropriate spacers could fit all our 120mm, 126mm, and even 130mm spaced hubs. They might need a special made lock ring, but I'd do my best to make it possible to utilize the existing ones. In many respects this would solve all our woes in finding that perfectly geared freewheel for our vintage rides.

noglider 

Pastor Bob, wasn't the Regina freewheel perfect in that respect? You could build anything you wanted. It was complicated, though.

The Golden Boy 

I know- Old reply to an old question on an old thread...

I have a Suntour XC Comp working in Friction with a 34T cog. I do not think it will handle much more.

Looking at the Suntour LeTech that came with my Voyageur- I think that would handle a 38. The triple pivot is an amazing beast.


This isn't mine, and only the first pivot appears to be engaged on that puny little cog back there.

pastorbobnlnh 

Tom,

Regina BX & CX and the Suntour Winner family had somewhat more variation in how they could be customized, i.e. 5, 6 or 7 speeds, wider range (especially in the high gears with 12T & 13T cogs), but they did this at the expense of having variations in where threaded cogs went on the body.

For instance, the New Winner (first generation) has room for two splinned cogs in the largest position, then takes one size threaded cogs in the mid positions, and finally a top small cog with yet a different thread diameter. Therefore you'd need three different set of cogs and three different diameter of spacers (Perfect/ProComp only needs two). Then there are the multible variety of the smallest threaded together.

Regina CX, BX, Corsa and Oros all need at least 4-5 variation of cogs. Sachs about the same. Shimano has to have at least 6 different variations on cog mounts.

Thus, IMO, the Perfect/ProComp bodies were the simplest to customize.

CrankyFranky

I'm with you! I've had the same Perfect FW bodies installed on my two road bikes since 1983 - only swapping out cogs as they wear, and occasionally flushing and re-lubricating. It's a pity that it's virtually impossible to find unworn 19 tooth non-threaded cogs (center cog on a five speed) - that is the gear that I use most on flat terrain when touring. Sigh.

pastorbobnlnh 

Like this one?