Stealth bikes may fill troops' need for lighter, faster transportation.

• Author: Machi, Vivienne

A couple of never-before seen militarized motorcycles grabbed headlines at this year's Special Operations Command's trade show in Tampa, Florida.

The hybrid-electric, off-road bikes appear to be more than curiosities, however. Because of their stealth-like features and flexible fueling options, there is a chance that they could one day be part of the military inventory.

Hybrid-electric motorcycles--that can be powered by either heavy fuels like diesel and jet fuel or by a lithium ion battery--offer a longer range and a quieter ride than other motorized vehicles, said Christopher Orlowski, a program manager at the Defense Advanced Research Projects Agency, who is leading the motorcycle research.

"Raids can require infiltration into an area, and if you can do it more quietly, then that can add benefits into the operation," he said.

The two prototypes--Logos Technologies' SilentHawk and LSA Autonomy's NightMare--were unveiled at the 2016 Special Operations Forces Industry Conference. They can each run for at least 120 miles on combined electric and heavy fuel sources, reach a top speed of 80 miles per hour and maneuver in and out of areas at about the noise level of a normal conversation. They can also charge portable electronics, saving precious space in soldiers' rucksacks, Orlowski said.

The program was funded in 2014 through small business innovation research grants, which provide funds to smaller companies to demonstrate the feasibility of a product or technology.

For the hybrid off-road motorcycles the objective was "to demonstrate a lightweight two-wheel drive hybrid-electric off-road motorcycle [... ] powered by heavy fuels, capable of short periods [of] electric-only propulsion, and usable as a portable electric power source for soldiers in the field," according to documents.

The stealth motorcycle effort is "not a traditional DARPA program," Orlowski said in an interview, "but it was in line with our mission to create disruptive programs for national security."

Hybrid-electric propulsion in a ground vehicle could be a benefit to special operators, although a motorcycle may not be the ideal vehicle, said James Hasik, a military vehicle expert and senior fellow at the Atlantic Council's Brent Scowcroft Center on International Security.

"In the late 1930s, everyone had a motorcycle unit, which was the reconnaissance team, similar to a cavalry on horseback," he said. But the same issues that rendered horseback cavalry obsolete --namely...