Dura-Ace 10 hubs/cogs are indeed different...smaller...in order to get enough teeth of the 10mm pitch chain onto a cog (minimum size was 14T, even with the smaller thread diameter).
D/A 10 - 33mm x 1.058mm pitch (or 1.299" x 24tpi (or, illogically, 33mm x 24tpi))
The rest of 'em I'll leave to the experts, but I believe the following to be the case:
I.S.O. - 1.375" x 24tpi (or 34.92mm x 1.058mm pitch) British - 1.370" x 24tpi (or 34.80mm x 1.058mm pitch) Italian - 1.378" x 24tpi (or 35.00mm x 1.058mm pitch)
I believe that there were some 10mm pitch cogs made for regular track hubs (I'm interested in some, if anyone has any), but I've never heard of 1/2" pitch cogs for D/A 10 hubs.
Scott Minneman San Francisco, CA
-----Original Message----- From: classicrendezvous-bounces@bikelist.org [mailto:classicrendezvous-bounces@bikelist.org] On Behalf Of Bob Freitas Sent: Thursday, February 23, 2006 8:26 PM To: CLASSIC RENDEZVOUS Subject: [CR]Dura ace 10
I have recently purchased a track wheel which had a Dura ace 10 cog fitted, are these threaded differently? seems Campy or 888 marked track cogs just drop on over threads on hub.
BOB FREITAS
MILL VALLEY,CA