Fixed gear or single speed bikes have narrow tyres and are kept very simple without extraneous accessories. They are generally ridden in street clothes.
Fixed gear bikes have the pedals directly connected to the wheels so that you have to pedal all of the time the bicycle is moving—even downhill. They are known as ‘fixies’. A reasonably high level of skill (or nerve!) is required to ride a fixed gear bike as they often don’t have breaks and are controlled by the speed of the peddling.
A single speed bike has only one gear but allows you to coast on the bike, ie. on a hill the wheels will continue to go around when you stop pedalling. These bikes do have brakes.
