The fixed gear bicycle he oldest and simplest type of bicycle is the "fixed-gear" bicycle. This is a single-speed bike without a freewheel: that is, whenever the bike is in motion, the pedals will go around. You cannot coast on a fixed-gear machine.
Many track bicycle any enthusiastic cyclists ride such bicycles by choice, at least part of the time. Why would anybody do that? It is not easy to put into words. There is an almost mystical connection between a fixed-gear cyclist and bicycle: it feels like an extension of your body to a greater extent than does a freewheel-equipped machine. If you are an enthusiastic, vigorous cyclist, you really should give it a try.
There are many reasons, including:
Fun, Fitness, Form, Feel & 'Ficciency!
by Sheldon "Coasting Is Bad For You" Brown
https://www.sheldonbrown.com/fixed.html
