> Are there different threads for the reverse-threaded ramp
> on Campagnolo
> track hubs? I ask because I have a Campagnolo rear track
> hub, with a 64
> date, and the Campagnolo lockring fits smoothly on the ramp
> and screws in
> easily, though its threading is not indicated. An English
> threaded cog
> screws onto the cog threads. When using the Campagnolo
> lockring on another
> track hub, one marked as having English threads, the lockring
> fits loosely
> and does not secure a cog. Using a different Engish threaded
> lockring on
> the Campagnolo hub, it begins to screw onto the ramp, but
> then immediately
> tightens. It probably could be screwed onto the hub, but it
> would take
> force to get it on the ramp close to the cog.
>
> I am asking then what threads, aside from English,
> did Campagnolo make track
> hubs, and would it have been common to have the cog
> threading one dimension and the ramp another?
Tom,
You might not believe this answer - because it will seem to
run counter to the experience you've described - but as far as
I know, what I'm about to write is true. If I'm mistaken, then
perhaps someone will chime in and we'll both get some "higher
education."
OK - here goes: Campagnolo made track hubs with only one
style of threading. The threads for the sprocket are the same
as the threading for Italian threaded freewheels, i.e 35 mm x
24 tpi. This is close enough to British threading, and there
is enough variance in manufacturing tolerances, that British
(or ISO) threaded sprockets will fit on Campagnolo hubs and
vice versa.
The lockrings are another matter. British/ISO lockrings are
1.29" x 24 TPI and Campagnolo lockrings are 1.32" x 24 TPI.
They don't interchange.
For whatever it's worth, here's the story for French track
stuff. The lock rings on French track hubs are 33mm x 1mm.
Yet... the modern French track hubs use British/ISO threading
for the sprocket. But, the sprockets for older French track
hubs used the same threading as French freewheels. The trick
is to know when a particular French manufacturer switched from
"full French" threading to the "mixte" style. I don't.
Best regards,
Fred Rednor -Arlignton, Virginia (USA)