In turn, Harley developed the WLA model, based on the civilian WL with its 740cc side-valve V-twin engine, but extensively modified for dedicated military use. Among the changes were blackout lights, engine guards, high-mounted exhausts, a cut-away rear mudguard to prevent mud accumulation, a more efficient air filter, ammunition boxes, a leather scabbard for the Thompson submachine gun, a six-volt generator and mixed-use tyres suitable for off-road terrain.
The first examples entered service in 1940, but after the attack on Pearl Harbor in 1941, production increased dramatically, with around 70,000 WLAs built by 1945.
As expected, the WLA designation carried specific meaning: W referred to Harley-Davidson’s Flathead engine series, L to the “high-compression” variant (though in practice the compression ratio was kept low to allow the use of poorer-quality fuels), and A stood for Army, indicating service with the U.S. military.
These Harley-Davidson WLAs were used primarily for escort duties, reconnaissance, patrol work and dispatch riding between military units. However, they did not serve exclusively with the U.S. Army: around 26,000 were supplied to the Soviet Army through the Lend-Lease Act, most of them fitted with M72 sidecars which, among other roles, were used to carry an 82mm mortar.
Within the U.S. Army, the Harley-Davidson WLA saw extensive use across the European, North African and Pacific theatres, ridden by soldiers known as Dispatch Riders.
After the war, many WLAs were sold off as military surplus and ended up in the hands of civilians and motorcycle clubs. Numerous examples were modified and would go on to directly influence the Bobber and Chopper movements of the 1950s and 1960s.