I'm just putting this out there for the mental ************ aspect since I don't personally intend to try it:

say you've got rear wheel you really like with a nice freewheel hub. You want to convert it to fixed and don't want to make it a suicide hub. Couldn't you take the whole wheel to a good machinist, and have him lathe down the leading edge of the threads, and reverse thread lock ring threads? It seems like most freewheel hubs have a wide threaded area. There should be enough material there to do this? Is this really crazy, or is it just crazy enough to work?

For much less money and effort you could just buy a real track hub.

Now this IS suicide. A top shelf hub will have just the right amount of material to make it strong. Not lots of extra weight creating material to confound the marketing department.
Example.
The new Campy hub weighs 100 grams more than last years for you fixed gear enthusiasts who want to machine some of it off.

Maybe it could be done on some beefy older hubs. This has already been brought up, nobody has done it yet.

If you don't want to take off TOO much metal, you could have the machinist take off less for a larger diameter lockring, and then have him make you a custom lockring too.

I agree it's likely not cost effective, but it does seem doable. If hub manufacturers were THAT concerned with the lightest possible hub, they would not use standard sizing, and you'd have to buy proprietary freewheels for every brand. I don't think the couple mm difference between freewheel diameter, and lock ring diameter would usually not have much effect on overall durability of a hub.

I don't have any particular desire to try this, but I do think it would be a relatively straight forward job for a competent machinist, and probably would not cost all that much.

Still cost-wise, it probably would not be worthwhile for an inexpensive hub, and would likely be a travesty to perform this operation on a high end hub.

as a person who has worked in a machine shop, I'll chip in with these comments:
1) you'd have to take apart the wheel down to the hub for this - I seriously doubt anyone would do this with the spokes and rim attached
2) its actually not -that- easy to put those fine pitch left hand threads on there
3) by the time you've paid the machinist $60 for the job you shoulda just bought a track hub from ebay
4) nice hubs probably have rolled threads which are quite a bit stronger than cut threads and you'd be hard pressed to find a machinist with the right threadforming tool to make the left hand rolled threads for you.

I say, nice idea but save your money and time

Suicide hubs are safe enough so that you don't have to mess with all that jazz.

If you have ever had the pleasure of attempting to remove a cog from your stripped suicide hub you know how precious little metal there is on the hub between the aluminum treads and the steel bearing cup.

Enjoy

Ditto from someone else with machine shop experience. As jondrums pointed out, any shop that might have that kind of threadforming tool just lying around would most likely charge you more than $60 just to set up.

I also can't see how it could be done on a machine that could keep decent tolerances without the hub being separated from the rim and spokes.

The guy most likely willing to give it a try will be some old timer who chucks your hub into a some gigantic pre-WWII turning center, futzes around for about six Pall Malls, and ruins your hub on the first pass, blaming the material with a shrug. Every town has this guy.

P.S.: Huh-huh. "'Chip' in".

hey I SAID it was a crazy idea