The WWII-Era Harley-Davidson That Was Originally Built For The Allied Troops – SlashGear

While the WLA was a capable bike in the European theaters, the same couldn’t be said for its use in the desert regions of North Africa, where the U.S. was fighting the Desert Fox, General Erwin Rommel, and his forces.

The V-twin engine of the WLA was overheating (as was the Indian 741), and the military needed a bike that would keep its cool. They also needed something that wouldn’t keep getting gummed up by the desert sand, so they tasked Harley and Indian to come up with a solution.

Harley-Davidson came up with the XA (Experimental Army), a design based on BMW’s R71, which Rommel’s Afrika Korps troops had been using with great success. The XA was an opposed-cylinder motorcycle with the cylinders stuck side by side instead of the usual slipstream inline design. The air-cooled design would keep the engine cool by placing them out in the wind. It did precisely that and plummeted oil temperatures by almost 100 degrees over the WLA models.

The 750cc, 23 horsepower engine had low compression and a top speed of only 65mph (via Hemmings), but it had high torque. They removed the chain and sprocket, notorious for getting torn up by sand, and replaced it with a shaft drive. The XA was equipped with a four-speed, but interestingly enough, this was Harley’s very first-hand clutch and foot shift motorcycle. The company wouldn’t use this setup again for ten years with the 1952 Panhead (via Wheels Through Time).