A fixed-gear bike, also known as a fixie, is a type of bike that has a fixed rear wheel, which means that the pedals are directly connected to the rear wheel. Unlike a regular bike, a fixed-gear bike has no freewheel, so you cannot coast or stop pedaling while riding. This means that you must constantly pedal while riding a fixed-gear bike, and you can slow down or stop the bike by resisting the pedals with your legs.