Now I ALWAYS hear people talk about how useless a rear brake is on a fixed-gear bicycle. Someone said on youtube (which I think was pretty ignorant- its up to you what YOU think) that a rear brake actually makes riding worse because it locks up the rear wheel- isn't locking up the rear wheel how you brake on a fixed-gear ANYWAY?

Well in any case, consider this:

Just because your feet are "moving" on the pedals does not mean you are exerting power on the wheels. Thats how I slowed down when my cog/lockring were jacked up. When you do not exert power on the pedals, you are not powering the bike- you are in effect coasting- but the pedals still move because of the nature of the gear being fixed to the wheel.

So you can essentially coast on a fixed gear by simply not exerting power to the pedals, and letting your legs loose- which would by implication mean that a rear brake is not useless at all.

Just my two cents. Any other people wanna put in theirs?