A fixed gear bike translates to a bike that functions with a fixed rear wheel cog. Basically from a mechanical standpoint, the quintessential difference between riding freewheel or fixed is that with a freewheel cog there is a bearing that allows the back wheel to rotate free from the movement of the pedals, chain and allows riders to stop pedaling at any point of the ride to enjoy their momentum. On the contrary, fixed gear cogs intentionally lack the bearing that separates wheel movement from drivetrain movement, meaning the pedals move in a fixed sync with the rear wheels. Ultimately, you cannot coast while riding fixed, your pedals continue to move with the rotation of the bike.
Therefore, if you're riding fixed and your pedal moves the chain, which rotates the rear cog that spins your rear wheel, your bike will move in whichever direction the pedals/chain/cog move.
Yes, that means you can ride forward or backwards while riding fixed; However, that's only one of the benefits that come with these bikes. Fixed gear bikes are single speed, if you think this is unfortunate, try looking at it from the angle of less is more. As a result of being single speed, Fixies tend to weigh less than their multi-geared contenders -needing no shifters, cassettes, derailleurs, etc-. In terms of cycle efficiency, riding fixed takes the win as the transfer of user effort to the rear wheel is delivered almost seamlessly.
One of the most common questions surrounding fixie culture is how do you brake and stop one? Contrary to popular knowledge, all bikes sold in the US are required to come with at least a front brake, this standard does not exclude fixies. The most efficient way to slow one down is indeed using brakes; however, many find it more fitting to counteract against the rotation of the pedals by locking the pedals in a horizontal position, and in turn locking the rear wheel causing a skid stop.
Just as riding freewheel isn’t for everyone, neither is riding fixed. However, both come with advantages. With that in mind, all Loco Fixies and FG Cruisers® are shipped with flip-flop hubs allowing riders to switch from freewheel to fixed gear with the painless flip of the back wheel.