Originally Posted by
JohnDThompson
No. Both sides of most Helicomatic rear hubs use non-standard 5/32" balls, with the cones and cups to match that size. Standard hubs use 1/4" balls. There is apparently a "Sport" model Helicomatic hub that uses standard 1/4" balls, but I've never seen one in the flesh.
http://www.borgercompagnie.com/helicomatic/specs.html
OK, looks like John has solved the mystery. I'm not sure how to confirm if my hub is a 500 or Sport model, but if I remember right it's a 500, in which case I'm outta luck. Also if I recall correctly, I wasn't able to find cones for the standard Atom Sport hub, which seems odd given that it was a widely-used hub (wasn't it?) Shouldn't some LBS out there have a few of these in their bin?