I was planning on buying a bike that is already converted to single speed. For $50 he offered to make it fixed. Seems kinda cheap when you consider a new hub or rear wheel is in order. I asked him about this. He replies:
"The hub is a freewheel hub and allows for a singlespeed or fixed, I have several methods for this... don't worry about cogs slipping in general, the way I do it works great. In fact, I was just discussing with sheldon brown that he should put a couple of things on his site, one of them being getting a cog locked super tight."
I wish he would have elaborated more. It just seems a little sketchy. I wasn't looking for a fixed anyway but the thought has crossed my mind. I told him I would consider having him "fix" the bike but if it involves changing the hub and not altering the freewheel setup.
man I feel like the guy I'm talking to over email is a user of these forums.
Disclaimer: I'm not hatin', I just want advice.