Though track bikes were designed to be used in a velodrome or outdoor track, they have become popular among bicycle couriers enthusiasts. Track bikes have no brakes and are in a fixed gear, so they can't coast. In order to stop, the rider must control his strides, which can be difficult if you're unfamiliar with fixed gear riding. These bikes are designed for speed and tight turns, with a higher bottom bracket and a seat post and handlebars that encourage an aerodynamic riding position. Riding a track bike in the streets is possible, but getting used to the bike can be a challenge.