Sutherland's 5th Edition (1990) lists the following lockring threads:
Campagnolo - 1.32" x 24 TPI
English - 1.29" x 24 TPI
French - 33 mm x 1.0 mm
I would think that those with old French track bikes must have a difficult time finding lockrings. The cogs are probably even worse, since they are probably much rarer than French threaded freewheels, and unlike the lockrings of which you need only one, you need a variety of cogs to change ratios to match conditions, plus they eventually wear out.
Anyone know what the cog thread was on older Campy track hubs (I assume the current ones are ISO)? Did they use one thread consistently, or were they available with Italian, English and French thread like the road hubs?
Regards,
Jerry Moos
Houston, TX
> This is a bit esoteric, but may be important to some folks: There is more
> than one "standard" for lock ring threading for fixed gear hubs. I was
> trying to fit a lock ring to an "FB" (Italian) hub this morning, and the
> first rings I tried just wouldn't fit. So, using the hubs available, I
did
> a bit of measuring. Sure enough, I got the following results (where I'm
> using lines of dashes to let you know where the line breaks are, since
this
> can get messy with email):
>
> F.B. (Italian): 1.313" (33.4 mm)
> -----------------------------------------
> Harden (G.B.) 1.290" (32.75 mm)
> ------------------------------------------
> Paramount (US) 1.305" (33.2 mm)
>
> The Paramount hub barrel has been rechromed, so I suspect it is the same
as
> the Harden, and that this is a "British Standard." I did not check the
> thread gauge, since threading on seemed no worse than class B (will work,
> but doesn't feel perfect).
>
> The one lockring I found that did fit the FB was real loose on the Harden
> (sort of like a 14 mm pedal in a 9/16" hole). If you find such loose
fits,
> I would not recommend using them if you count on the lock ring for
braking.
>
> I don't have a Campy track hub to check. There was no info in Sutherland
> 2nd Ed, the only one I have.
>
> Your mileage may vary...
>
> harvey sachs
> mcLean va