Two Wheels, One Gear

Well, I lied. It has two gears, they are just, well, the same gear. Confused? My mountain bike is a single speed (remember, I like primes) and it has what's called a flip flop rear hub. One side freewheels, the other side is fixed, meaning you can't coast. Ever. If the wheels are moving, you're pedalling. Try that on the trails! To change from fixie to free and back again, you just unbolt the rear wheel, turn it around and bolt it back on.

Fixed offroad sounded like fun until I tried it. Then, not so much. It's a friggin' hoot in traffic though and I can see why messengers prefer it.