Difference b/t old 6 speed hub and new fixed/ss hub
 

Ok guys, lets hope this isn't a stupid question! What is the difference between the threading on an old 6 speed freewheel rear hub and a new threaded fixed/ss hub. Will a new ss or fixed cog thread on and work on those old hubs or what kind of modification has to be done in order for this to work. Will there be chainline issues...etc? It seems like more people would do it if it was easy, so I'm guessing there are big differences...help!

The only difference between an older freewheel hub and a hub for a fixed gear is a set of smaller, counter rotating threads for a lockring. The lockring will hold on the fixed cog if you backpedal. If you are just building a single speed with a BMX freewheel then use a freewheel hub.

You may have to change the spacers around on your old hub to get the right chainline. A new flip/flop is generally going to be preset for 40-42mm chainline. Your old one probably will be off until you play with it.

Thanks a bunch guys! I've gotta get started on my new SS wheelset with my really cool old high flange hubs!

I am sitting here at my office desk with the set of hubs you are describing. I got them in a $100 box o' parts from another guy. He has put two normal sized nuts on the non-drive side to space things correctly. Then he's loctited a cog on the other side. I will not be going with the suicide hub, and already have a fixed gear bike, but I'm itching to build them up.