I run a rear brake and flip my wheel, obviously it depends on how long your drop outs are but I get 5 teeth difference and the brakes are on the rim in both positions... Althought that is in the standard position for brakes underside of seat stay would make it harder...
I do also ride fixed (from your post it looks like you do too) and have a front brake, so even if it weren't to work in one position I would probably get it to fit the wheel when polo gear is engadged and just use feet for braking on the road.
The only hub that might work as a drum brake whilst being 'fixed' is the s&a s3x hub, with a bit of modding. It's a geared fixed hub, but there has to be some play in it to change gears so all reports i've heard about it said don't bother. But you could easily replace one of the gears with something that jams (there are tutorials for modding s&a hubs on the net)... But obviously there is the possibility that if you changed gears at the wrong point it would jam completely!
I run a rear brake and flip my wheel, obviously it depends on how long your drop outs are but I get 5 teeth difference and the brakes are on the rim in both positions... Althought that is in the standard position for brakes underside of seat stay would make it harder...
I do also ride fixed (from your post it looks like you do too) and have a front brake, so even if it weren't to work in one position I would probably get it to fit the wheel when polo gear is engadged and just use feet for braking on the road.
The only hub that might work as a drum brake whilst being 'fixed' is the s&a s3x hub, with a bit of modding. It's a geared fixed hub, but there has to be some play in it to change gears so all reports i've heard about it said don't bother. But you could easily replace one of the gears with something that jams (there are tutorials for modding s&a hubs on the net)... But obviously there is the possibility that if you changed gears at the wrong point it would jam completely!