Highlights

• This Square Four Deluxe Model features fishtail mufflers, chromed and pinstriped rims, a detachable rear wheel, larger gas tank, and a side stand
• This was the last year of production before Ariel focused on single cylinder machines for the military during World War II
• It still shows the 1000 inscription on the side cover as opposed to the Square Four present on later versions produced during the 1950s
• It features a new (for 1939) spring frame which is 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