Rear cog compatability

I just got my first fixed off ebay and I am loving it. However the bike is currently set up with 44/18 gearing which I think is just a little low for my commute. I would like to get a 17t cog (and possibly a 16t) and I was wondering how I can tell which cogs will fit my hub? There seem to be a few different styles of interface. I would take a look myself but I don't have a chainwhip or lockring remover yet.

The hub is a Maillard track hub, I am not sure what vintage. Any ideas what will fit and who might sell them?

Cheers,
Tony

First you need to see what width of cog it is: 3/32" or 1/8" (ie narrow road chain or wider track chain).

Thats it really. Hub-jub.co.uk, Condor, Brick Lane, Brixton Cycles should all be able to help you out from there.

Obviously as we're dealing with bike parts, nothings that easy. There are actually multiple threading standards for hubs/cogs. Typically you see either ISO or English threading

I.S.O. 1.375" x 24 tpi 34.92 x 1.048 mm
English 1.370" x 24 tpi 34.80 x 1.058 mm

But you can also see:

French 34.7 x 1 mm 1.366" x 25.4 tpi
Italian 35 mm x 24 tpi 1.378" x 1.058 mm

ISO, English and Italian are all semi-interchangeable but you're best sticking to one threading standard if you can.

Maillards may be a little weird though, they're french made (?) but I think they have ISO threading (as they tried to compete with Campy).

The only other weird thing you see is the Miche cog carrier systems. Pretty obvious to spot.

Actually you may have a french threaded hub.

Are there any discernable markings on the hub? These Maillard 700s on Ebay claim to be French threaded:
http://cgi.ebay.com/MAILLARD-rear-hub-700-pro-PISTA-NOS_W0QQitemZ170132576899QQcmdZViewItem

No-one makes french threaded cogs any more AFAIK

So:

1) Post some more details about the hub here or
2) Go to your LBS and have them figure it out.

pip Actually you may have a french threaded hub.

Are there any discernable markings on the hub? These Maillard 700s on Ebay claim to be French threaded:
http://cgi.ebay.com/MAILLARD-rear-hub-700-pro-PISTA-NOS_W0QQitemZ170132576899QQcmdZViewItem

No-one makes french threaded cogs any more AFAIK

As luck would have it I can just make out a very faded "700" on the barrel of the hub. It is etched in the steel itself, not a sticker like on the ebay link but otherwise it looks like a less shiny version of what you linked to.
The chain is 1/8" but it sounds like it is probably a French thread. Thanks for the pointer in the right direction!
Anyone got a 17t or 16t French threaded cog they would like to swap for some pound notes by any chance?