6 bhp, 584 cc horizontal twin engine.

In the early 1920s, Harley-Davidson experimented with a fore-and-aft twin, similar to the contemporary Douglas in the UK. The Flat Twin Sport Model was built between 1919-23; it was developed during WWI and introduced in November 1918.

The horizontal twin displaced 584 cc and carried the engine and three-speed transmission low in the chassis. In addition to the fully enclosed chain guard, which saw the chain lubricated by a spray of oil from a breather pipe, the Sport model could be had with full electric lights. Coil ignition was reserved for the WJ model, while magneto ignition and accessory gaslights were used on the WF model. Smooth and economical, it proved itself to be quite popular in Europe as well.

This rare WF Boxer is certainly an unusual motorcycle and quite rare, finished in the traditional shade of olive green with black. An older restoration that has aged well, the wheels are period-correct beaded-edge units, and an early headlamp is fitted along with a Bosch ZAV magneto. The brown leather sprung saddle is an original Mesinger item and is in lovely condition. Additional features include a rear carrier. Italian registered with old registration plates mounted to the front and rear, the paintwork is generally very presentable. An excellent example of early American motorcycling, this machine would make a welcome addition to any important Harley-Davidson collection.