This site is dedicated to enthusiast bikers.
Also known as the cub or moped, it is a motorcycle with the riding ease of a scooter. The first and most successful model ever is the venerable Honda C70, which revolutionized riding in the ‘60s and is still being produced in other parts of the world. The term “underbone” came from the large single spar frame that connect the front steering neck to the lower center of the frame and acts like the spine of the bike. The gas tank is under the seat, the frame is hidden by body panels while the motor is mounted low near the bike’s center line, usually coupled to a wet-clutch semi-automatic 4-speed rotary gear box.
It’s actually a sportier STANDARD BIKE except the engine and the suspension is tweaked for serious speeds and leaned-out cornering. The rider leans more forward, his hands hold on to handle on the handle bars that are mounted at almost the same level as the gas tank. The frame is generally exposed and sometimes, a small front fairing called a bikini fairing diverts some air above the rider’s helmet. Engine ranges from 150cc singles to 1600cc 4-bangers that can run up to nearly 200 kph.
Basically, a SPORT BIKE minus the body fairin.
Its a long low bike with a long wheelbase(the distance between the centers of the front and rear wheels); the handlebar is normally mounted on a level between the rider’s chest and his chin while the foot pegs are in a forward location. The front fork is more leaned back than the STANDARD BIKE and the engine-of-choice is usually a V-Twin with displacement ranging from 150cc to 2300cc. Harley-Davidson is the most iconic cruiser with the largest motor.
(Source: Motorcycle Magazine: http://www.motorcycle-ten.com)