Originally Posted by
JohnDThompson
I wouldn't call it "a big mistake;" it's just kind of pointless. You already have a rear brake on a fixed gear: your legs. Since the effectiveness of the rear wheel brake is limited by friction with the road, your not likely to get any better braking performance by adding a caliper. At best you just redistribute the effort between your hand and your legs.
Once I spin up to where I'm bouncing on the saddle, I don't have much ability to brake using the pedals. That's pretty frightening on long downhills. I really want the rear brake.
em