The 650 GS was produced by Aprilia Motorcycles in Italy for BMW. Its 39.79 cubic inch (652 cc) single-cylinder four-valve rotax engine with chain drive is water cooled. BMW utilized road car technology in their cylinder head construction, employing fuel injection, digital motor electronics and a catalytic converter. It puts out 50 horsepower at 6500 rpm with 44.3 pound-feet of torque at 5000 rpm. It has a five-speed transmission.
The repositioned 4.6-gallon fuel tank (with a 1.2-gallon reserve) fits into the frame triangle beneath the seat. The lower center of gravity has improved handling, especially cornering on switchbacks. The air box, oil tank, coolant reservoir, electrical equipment box and battery are all under the tank cover. The twin exhausts are under the rear seat. The total redesign includes an asymmetrical placement of gauges on the cockpit and new handlebar controls. The hand grips are heated and there are three different options for seat height, although its stock height is at 30.7 inches. The bike weighs in at 425.5 lbs. It is 85.6 inches long and 35.8 inches wide, with a wheelbase of 58.2 inches. There are several hard and soft luggage options, including a soft back for a luggage rack and passenger seat and a hard top case and saddlebags.
The lightweight ABS antilock brake system was a combined development by BMW and Bosch Braking Systems. By using a cockpit-mounted switch, you can turn off the ABS to make it more suitable to off-road use. The front brake has a single 11.8-inch (300mm) disc with a two-piston floating caliper, while at the rear there is a 9.4-inch (240mm) disc with a single floating caliper. The front suspension boasts a Showa 1.6-inch (41mm) telescopic fork which provides 6.7 inches (170mm) of spring travel. An additional stabilizer was added in this redesign to strengthen the front forks, creating optimum smoothness in the ride.
