Yep, their speed and agility can’t be beat.
How were they used? Relaying a critical order, getting ammo to a machine gun, or scouting miles ahead of an advancing unit.

The U.S. Army first successfully used Harley-Davidson motorcycles to hunt down Pancho Villa and his troops during the Mexican Revolution! The motorcycles gave the U.S. a speed advantage against the horse-mounted Mexican revolutionaries. Subsequently, the U.S. government ordered another 20,000 to keep our troops company in Europe during World War I.

The first time motorcycles were widely deployed as in WWI. Motorcycles were actually one of the most widely-used form of transportation in the Allied arsenal (the US alone ordered over 80,000: 50,000 Indians, 20,000 Harley-Davidsons, and various others.) They were quick (for their day), agile, durable, and able to navigate dangerous terrain with relative ease.

The Indian Motorcycle Company, at the time being the #1 American motorcycle manufacturer, focussed nearly all of its production resources on the war effort.

As a result, 50,000 Indian Powerplus Big Twins were produced, which were both faster and more maneuverable than the Harley alternatives due to an improved rear suspension.
1916 Indian Powerplus Big Twin

The Harley-Davidson Model 17 had a 61 cubic inch F-head engine (15 hp), with a 3-speed transmission and a gas tank mounted hand-shifter.

Most of these military motorcycles came outfitted with a variety of accessories, including hospital stretchers, passenger sidecars, shields, and fully automatic machine guns.
Harley Davidson Model 17F_J

The British government knew that they would need more effective means of delivering messages between troop formations on the front line. With the instability and unreliability of radio transmissions, the Brits decided that motorcycles would have a significant role.

After a lot of testing, the government settled on the Triumph Model H. The single cylinder-powered, air-cooled, 499cc motor was slow with only 4hp, but it proved exceptionally reliable on the battlefield and was consequently nicknamed “The Trusty”.
1915 Triumph Model H

Like their American allies, Brits outfitted their “Trusty” Triumphs with sidecars, machine guns, etc. During WWI, the British sent 30,000 of the Model H into battle.

Entire infantry units were mobilized on motorcycles. And, they also provided an ideal way to rapidly deploy machine gun crews into position. Medical units used them to evacuate wounded on stretcher-equipped sidecars and to return medical supplies and ammunition to the front lines. They were also used for reconnaissance and for doing security patrols.

While WWII is often said to be the pinnacle of the military motorcycle, it actually played a lesser role compared to the direct combat operations they saw in WWI. Where motorcycles really found their stride in the European theater was again as the transportation choice of messengers, helping to close the wide distances between mobile forward units.
Hundreds of military motorcycles

By World War II, Harley-Davidson had become a leading American motorcycle company, and when war again broke out in Europe, Harley-Davidson responded.

This time, they modified their popular civilian model, the WL, into the WLA. It was a sizable 550 pound machine powered by Harley’s reliable 45-inch flat-head motor. They were quick, easy to work on in the field, and could take a beating on the road. Over 70,000 WLAs were produced for the war effort,including thousands that went to the Allies.
1940 Harley-Davidson WLA

But as prolific as the WLA was, the Allies soon discovered how far their Harleys were lacking technologically when compared with captured German motorcycles.

The Indian 841 was a motorcycle designed for desert warfare. It pioneered the drive-train configuration later popularized by Moto Guzzi, having a longitudinally mounted air-cooled 90-degree V-twin with shaft drive to the rear wheel.
1941 Indian 841

During World War II, the US Army requested experimental motorcycle designs suitable for desert fighting and offered Indian $350,000 in exchange for 1,000 shaft-drive, side-valve, twin-cylinder test motorcycles. In response to this request, Indian designed and built the 841.

The Indian 841 was heavily inspired by the BMW R71 motorcycle, as was its competitor, the Harley-Davidson XA.
However, unlike the XA, the 841 was not a copy of the R71. Although its tubular frame, plunger rear suspension, four speed transmission, foot operated shifter, hand operated clutch and shaft drive were similar to the BMW’s, the 841 was different from the BMW in several aspects, most noticeably with its 90-degree longitudinal-crankshaft V-twin engine and girder fork. Also unlike the R71 and the XA, the 841 used a heel-and-toe shift pedal with heel-operated upshifts and toe-operated downshifts. The bike also had a low compression ratio of 5.1:1, meaning that it could be run on low-octane fuel.

The Indian 841 and the Harley-Davidson XA were both tested by the Army, but neither motorcycle was adopted for wider military use.

The BMW R71 with a 750cc (46 cubic inch) side-valve motor and shaft drive combination performed beautifully throughout Europe. When the fighting spread to North Africa in 1943, the R71 and R75 models proved impervious to the desert grit and grime that was beating up the Allies’ chain-driven bikes.
BMW R71_sidecar

So inspired were the Allies by the BMW design that many captured enemy R71s, resulted in America’s Harley-Davidson XA, the Soviet M72, the Chinese Chang Jiang 750 and the Russian Ural.

Like the “Trusty” Triumph of WWI, the Norton 16H was an exceptionally reliable single-cylinder bike that was good on gas, came with a 4-speed transmission, and had an excellent power-to-weight ratio, which made it both quick and nimble on the battlefield. By the end of the war, Norton had produced over 100,000 WD16Hs for the British Royal Army.
1932 Norton WD16H

During WWII, the British government announced that it was looking for a light, fast, reliable motorcycle to transport messages between commanders. BSA, the most popular motorcycle manufacturer in Britain at that time, came up with the M20…a heavy-framed, sidecar-mounted barge of a bike, powered by a low-compression 500cc single-cylinder. It worked so well that Britain’s War Office ordered more than 126,000 throughout the war!
1937 BSA M20

Royal Enfield was commissioned to develop several motorcycles for the war effort, but the tiny WD/RE was their most successful.
1939 Royal Enfield WD_RE

Known affectionately to British troops as the “Flying Flea”, the WD/RE were lightweight, 125cc motorcycles designed to be dropped into war zones by parachutes. The bikes were used by British paratroopers who had been dropped behind enemy lines. The “Flying Fleas” were troop favorites because their punchytwo-stroke motors could run on any gas, and they were light enough to carry over obstacles and through tight spaces.

Although they are used to a lesser extent, motorcycles continue to be evolved for military use. They have been used in most of the Middle East conflicts to some degree. They range from the Zero MMX (pictured below), an all-electric stealth machine (no sound, no heat signature) to models like the Hayes M1030 that can burn up to six different fuel types to stay operational in most possible circumstances.
Zero MMX electric


Resources used for this piece:
“The Complete Book of Police and Military Motorcycles”, Joseph Berk