In my years in the Hebburn Vics 1950 to 1955 most riders couldn't afford bikes with derailleur gears
So they rode fixed wheel one caliper on the front was the law then. I still used it when I made a comeback in 1978 at Eighteen stone. Took me 4 months to get down to Eleven and a half stone won lots of Veterans medals for the over 40s. Good old fixed wheel.