Hey folks,
I’m back with another question for you guys.
This is what I have:
In order to convert this wheel to a fixed gear bike, what do I need? a thread-on single speed cog and a lockring?
thanks
An axle and bearings would be helpful but yes, a cog is necessary and a bottom bracket lockring is arguably useful. A reverse-threaded ‘track’ lockring won’t fit (search for suicide hub).
What sort of hub is that? It looks like either:
- a very cheap swaged steel hub from the 1970s or later (why bother with a hub that rubbish), or
- a pre-1970s French or English hub that is somewhat more likely to hold together.
+1 Track cog and bottom bracket lock ring. Some loctite will help as well 
- Life insurance.
Probs cheaper to buy an old track rear wheel :-o
Lets just say that opinions differ on the need for lockrings. I know several riders who choose not to fit lockrings while racking up more kilometers on fixed each year (>40,000 km for one fellow in 2007) than some riders do in 5 years. Mind you, they aren’t too interested in skidding.
A track cog and BB lockring should work OK, just be sure to (a) crank them on hard (by rotafix or in a vice) and (b) use a thread locker like they already said.
Track hubs are obviously better because of the reverse-threaded lockring, but cost considerably more, regardless of whether you buy a pre-built wheel or get one built up.