jimmuller 

A high-flange Campy hub you find at a junkyard.

CrankyFranky

Erm... now that we've drifted into freehub territory for a few days, and me knowing nada about this, can one buy such a freehub and simply buy individual cogs/spacers to make one's own custom ratio, but with old-school 5-speed rear spacing? This would solve many problems for slow, arthritic folks like me - and finally allow me to forget about triple-izing my old 120mm frames. I never use a ratio higher than 87 gear inches these days.

In the last 30 years, I've had only two Suntour perfect 5 speed freewheels on my two road bikes and I've finally run out of 19T middle cogs just by wearing 'em out while touring. PastorBob sure is right about the fw bodies lasting forever. Just keep 'em clean 'n lubed. Now those new Suntour OLD freehubs ...

dddd

I'm not aware of any 5-6-speed cassettes (or reasonably-priced spacers) for sale at retail, but someone here might have a stash of these items.

jeirvine 

So what thickness cogs do those new 120mm free hubs use anyway? I would assume one could put together any number of 5/6 speed corsets given the right assortment of spacers, and those would be dead simple to machine or 3D print (compared to custom freewheel cogs.)

noglider 

You probably could make your own set of cogs to put on a freehub, but the work involved could be very, uh, involved.

I may have some cogs you can use, if you like, but even rebuilding freewheels is of questionable wisdom. (Sorry Pastor Bob.)

nfmisso

Freehub spacers can be aluminum tubing cut to length and double disk ground. Shimano and others generally use injection molded plastic spacers due to their high volume. 3D printing would be a waste, and is not capable of holding the thickness tolerances.

Even easier for a person without a lather; would be just to super glue three pieces of shim stock to the inside (so you know the chain won't hit them) of all the cogs except the largest. Shim stock can be purchased in a wide variety of thickness and materials.

Choose the number of cogs you want on the cassettes - get all the same, ie all 7 speed or all 9 speed for example, measure and/or look up the cog spacing for the cassettes you purchase, take them apart. Calculate how thick the shim stock needs to be. It is a LOT cheaper and easier to purchase complete cassette than to try to find individual cogs. Niagara has 13-23 and 13-30 HG50 7 speed cassettes on sale now for less than $15-

For example, lets say you purchase Shimano HG (or compatible) 7 speed cassettes which have 5.0mm center to center spacing; and you want to make a standard 5 speed 5.5mm spacing; you will need to add 0.5mm (.020") thick shims to the cogs and re-use the original spacers between the cogs. The 5 speed cassette will be 8mm too narrow (23.85 vs 31.9mm) for a 7 speed free hub - which will have to be solved.

Ref: Sheldon Brown's Bicycle Frame and Cassette Spacing Crib Sheet

jyl

I had a part cut by a water jet place. $60 minimum order and I got ten pieces, cut from 1/4" 6061 aluminum. I suppose one could have splined cogs cut in the same manner. No fancy tooth profiles. Aluminum cogs won't last long but at <$10 the pop maybe that's okay? Or the waterjet guys can cut steel too. Just need CAD files.

Darth Lefty 

They take 8 speed cogs and spacers, no need to invent anything.

Jeff Wills

From this previous thread: https://www.bikeforums.net/classic-vi...-sunxcd-2.html the speculation was that they would use 6 cogs of an 8-speed cassette. Not sure if that's for real.

noglider 

Aluminum cogs are baaaaad. Even if I were wealthy and thought nothing of replacing a $10 item every month or whatever, the time and labor would be stupid.

jyl

But . . . so . . . light

Jeff Wills

Allow me to introduce you to the French temptress: Sachs-Huret Jubilee derailleur (2200)

Darth Lefty 

There must be a diameter where it's ok, especially for the higher gears, if skip-tooth freewheels and aluminum chainrings are possible.

noglider 

True, but most freewheel cogs are 24t and smaller. I might do it with a 28t but not smaller. This is based on having done no relevant experiments with this.

ThermionicScott 

28T+ chainrings seem to last long enough when made of aluminum. Since it's generally the smallest cogs that wear out first, you could probably get away with making aluminum cogs in 20+. Both kinda depend on the rider and terrain, though.

Aristotle80

I just had a NOS 28H Dura Ace freewheel hub built up, early 80s era. (The hard part was finding a 28H rim that looked vaguely C&V instead of modern aero style. The shop basically said Mavic didn't have anything like that anymore, which disappointed me a bit.) Perfect for my 140-150Lb weight range, it's far and away the nicest wheel I've ever used. My experience in freewheels has been that some wear a lot faster than others. My French made 6speed FWs seem to wear a lot faster than the Shimano and Suntour FWs, I don't think the metallurgy was as good. I really only use the middle four cogs on 6 speeds, the 14t little ones and the 26-28t low gears always stay shiny. I enjoy taking the chain off the bike to clean it in detail, which I think helps everything last longer. I'd never use the removable pin type chains for that reason, and like KMC and SRAM.

Jeff Wills

French freewheel cogs are made of brie.