What is the difference between single speed bicycle and a fixed or fixie?

Question

bikes, bicycle

Answer 1

All fixies are single speeds, but not all single speeds are fixies.  That is, both types have only one final gear ratio.  But those that have a freewheel in the back are not fixies.  A fixie cannot be freewheeled, that is, you cannot coast.  If the rear wheel is moving your legs must be moving.

To complicate the answer, some single speeds have a flip-flop rear end, with a sprocket on each side.  One side is fixed and the other side freewheels.  So all you have to do to convert it is to remove the wheel and flip it over.  I have this setup on my track bike.  Since I no longer race on the tack I use it on the freewheel side for tooling around the neighborhood and some winter training.

Special note: if you introduce a freewheel to a single speed you will need brakes.  It's not a bad idea to have brakes on a fixie as well, but absolutely essential on a freewheel equipped single speed, at least on the front, and preferably at both ends.

See Sheldon Brown's single speed article on the link below.

Ben

Answer 2

Fixed and fixie are really the same and are a type of single speed, but what separates these into a sub-category is the fact that there is no freewheel hub. You cannot coast or back pedal. Since the rear sprocket is attached to the wheel if you stop pedaling your rear wheel will to or at least try to. Single speed just means that there is no shifting in the front or back. Bmx bikes are single speed but the also have a freewheel so the can  coast. Some bikes have a combination of the freewheel and fixed. They can coast but if you back pedal it acts as your brake

Answer 3

With no "freewheel", on a fixed wheel bike  if you pedal backwards, you go backwards, "fixed wheel" bikes are really only suited for track or trick, riding, since it also has no rear brake, the time taken to slow down is considerable, and they are usually used for speed work outs, at a proper track, where nothing will impede you, as you ride, try this on a road and you will have to pull your feet out pretty fast, or they will continue to go round with the pedals, until the bike comes to a rest, and possible knee damage will occur, if it is going at high speed....a single speed has no gearing, so you can not take advantage of differing gears to aid in you speed or effort, on slopes or differing surfaces, but it does mean that your feet can remain on the pedals, and the rear wheel can rotate without moving the pedals, unlike a fixed wheel bike.....