Ariel Square Four


  • Deluxe model featuring fishtail mufflers, chromed and pinstriped rims, quickly-detachable rear wheel, larger gas tank, and side stand
  • Last year of production before Ariel focused on single cylinder machines for the military during 1940 - 1945
  • Still shows the “1000” inscription on the side cover as opposed to the “Square Four” present on later versions produced during the 1950’s
  • Features a new for 1939 spring frame - essentially a plunger-style rear suspension for improved comfort
  • The 1000 cc square four was a compact design that held four pistons in a square layout with a centrally located cam in the center of a vertically split crankcase