Potential Numpty Question - Where can I buy a single cog ?

Fuzz Monkey Five
Fuzz Monkey Five Posts: 194
edited April 2008 in MTB workshop & tech
I took my rear wheel apart today to fix a broken spoke and noticed that two teeth are broken on a cog (22T I think) on the rear wheel.

I've looked on the web (evans, wiggle, chain reaction etc) and can't see just a single Shimano cog, all they sell are full 9 speed casettes. Can you buy a single cog ? Or is it a new rear casette ?

Cheers,
Dan.