Not fixed but there are 2 speed kick back, without or with coaster brakes, so you have a starting off gear and a once you get going , higher gear..
Sturmey-Archer | S2 Silver No cables , Other than the Brakes...


and a cable shifted gear hub which is using a fixed driver and has 3 speeds , direct and 2 reduction gears..

The S3-X ... ( I don't see it on the current site so it may be limited to what i already Out there .. in shops and online owner resales)

& abundant additional cable shifted non fixed internal gear hubs

not street fixie trendy ,but imminently practical for many decades to come..


Now If you are competing on a Velodrome - track that's another story..











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