Recently, I built up a NOS set of C-Record HF Hubs, and wanted to make sure everything was hunky dory, in terms of the cog thread interface. After an evening of comparing cog threads amongst different hubs and cogs I have on hand I'd like to give a few small notes on cog threads to prevent other users from screwing up their cog threads.

-The C Record hub threads are 1.37" X 24tpi. Newer record hubs are 1.37" X 24tpi. From what i can tell, the c-record era is the turning point in cog threading for campy hubs. Older low flange record and high flange record seem to be split between italian thread 35 x 24F and british 1.37" X 24tpi thread. Perhaps other campy heads will want to chime in about this.

-I have a set of beat up high flange record hubs. they *appear* to have been italian threading, and someone had thread on a steel british cog, basically chasing down the threads from italian to british. (insert world cup jab here). All of my british cogs thread on nicely, however the original campagnolo cog 35 x 24F which came with it, threads on quite loosely.

-The italian threaded cog 35 x 24F threads on the newer c-record hub 1.37" X 24tpi, however a tiny bit loosely. The campagnolo italian thread cogs are marked "italiano 35 x 24F", whereas the british thread cogs read simply "made in italy". however, i also have one british thread campagnolo 13T cog which has no text at all as there is no space to engrave.

-I have an identical looking set of high flange record hubs, they are in better condition and have never had another cog threaded on. the threads are definitely 1.37" X 24tpi, and the cog is a newer campy one. the cog interface is perfect.

-I had a 18T EAI cog (1.37" X 24tpi) which i intended to use, on the c-record hubs. The cog threaded only 95% on. It left a small 1mm gap between the hub body and cog. Of all the other cogs i have, campagnolo, suntour and dura ace, none of them had this problem. I threaded the cog onto a bottom bracket chasing tool, to clean up the threads. A bit of cutting oil, and a few minutes later and it spun on like butter.

I fell hard for an immaculate pair of Campy sun logo track hubs and the found that I wasn't going to just pick up any cog or lock ring. And further, that there were two or possibly three different threads for these. I still have to try to determine which thread the hubs are--British or Italian--on the hub. I also have no real idea what the lock ring needs to be. Using a caliper I get 1.313" X 24tpi (in metric it's 23.1mm) for the lock ring threads, but what does that mean?
I'm not finding it easy to locate either part for a reasonable amount. That makes me first want to be sure what the heck I need.
One other question I have is how likely is it to find a cog in 3/32"?
Thanks for the great post. Much appreciated. I'd love to hear your opinion on the above issues.
Bob

I don't have any thread numbers but I have run a number of Miche track hubs. Most have had lockrings that are bigger diameter than the standard ISO - Italian? Same as some Campy. I just don't know. When I bought a SunTour 12 tooth lockring to use with an EAI 12 tooth, I couldn't start it on the threads. Had Ti Cycles drill and re-thread to the Miche standard. And again when I set up another bike fix gear and wanted to do the same.

Later, I learned the hard way that not all Miche track ups use the Italian(?) standard and killed one using one of my existing Miche lockrings.

Ti Cycles can re-thread to the larger lockring thread but - it may be very expensive. The SunTour lockrings are very hard steel and very hard on the lathe so the work is both slow and costly to the shop. They do not have the Miche dies but do have the superior lathe that can cut any threads. The re-threaded rings spin on beautifully. I love 'em but I paid a lot.

Just FYI this thread is from 2006 so the OP is long gone. However 79pmooney had good advice. You could also reach out to Phil Wood who does make Campag compatible lockings they might know. Also you might consider asking the mods to move this to Classic and Vintage there are some super knowledgeable people there who would probably know or check Sheldon Brown who knew just about everything.

OP here, I'm still around!
You need a campy thread locking. Either the one with a C-diamond logo, or a Phil wood.
Cog-wise:
-you could probably get a non-campy 3/32 on there but you may need a thin cog shim behind the cog to get the lockring to properly engage, as campy cogs are thick
-AFAIK Campy only ever made 3/32 cogs in aluminium, all other campy cogs I've had were 1/8 and steel

I stand corrected. Glad you are still here.

I've used Miche 1.32" x 24tpi LH lockrings in the past; good quality and a fraction of the price of Phil or Campagnolo lockrings. But they don't seem to be available anymore…

I've seen an older NOS Miche track hub with lockring for the cost of the lockring alone.
Like buying a whole 70s Mercedes for $300 just to salvage the mint, not cracked or Sun damaged dash.
Phil