You can add a fixed or flip-flop hub to practically any bike. Stock 26" fixed wheels may be difficult to find though. I haven't seen them, but mainly for lack of never needing to look for one.
2011-09-02 16:28:26
10
Winter Project
Well it is that time again and I have to start planning for my winter project (the Map bike should be done by them.
I have decided that I would like to build a 26" single speed (fixed gear?)
so just wanted some advice from the tool junkies out there. - especially on the idea of fixed gear, I have never seen a 26" fixed gear wheel and wasnt really sure if they even make them. (I will be doing some googling after I post this.) but I was hoping for any advice you all could give.
Thanks
2011-09-02 16:21:47
You may be able to find a stock wheel. Finding a freewheel-only hub will likely be easier (the number of production singlespeeds is on the rise, and folks need to replace wheels), but if you look around hard enough, you should be able to find a fixed/free hub.
Another option is to find a freewheel only hub that accepts disc rotors, and use a TomiCog (assuming those are still around) for fixed gear scorchin'. Of course, that would exclude running a rear disc brake in fixed mode.....
2011-09-02 16:47:03
Whatever you do... Don't build a suicide hub like I did when I was a kid. Bad freaking idea.
2011-09-02 16:49:57
Im starting to think my winter project will be getting a fixed hub and learning to build a 26" wheel. 8-]
2011-09-02 16:53:02
Also a good plan. 
2011-09-02 16:54:58
Well thanks to the bycycling guide to complese bike repair and maintainence and youtube I rebuilt a wheel fromt he ground up.
cleaned the bearings
repacked the hub
relaced the wheel
trued it
stressed it
re-trued it
Im feeling pretty good about it, there is something to knowing that I can do these kind of things that gives me a very satisfied feeling.
2011-09-06 00:57:07
I hear ya... That's what keeps me learning and creating as well. 
2011-09-06 02:45:46
yeah me to, gonna do some work on the fall project, the Map Bike. I got another waterproof map from the guys at bikePgh so I can finish it.
2011-09-06 13:01:38
I would say there is nothing quite as satisfying as building a good wheel.
2011-09-06 13:45:51