Having only front brake is almost common for fixed gear bikes because they can break rear by retention and fixie counts as a commuter bike. Also it might be a

Having only front brake is almost common for fixed gear bikes because they can break rear by retention and fixie counts as a commuter bike. Also it might be a decent config for learning some BMX tricks because if you want to be able to do a barspin you can not have both brakes. And if you have a bicycle with a coaster hub and a front brake and your chain is off than you are effectively having only front brakes.