Posted on Monday, July 09, 2007 - 09:16 am:

BUELL FOCUSED ON INTUITIVE DESIGN AND ENGINEERING
Innovation that Enhances the Motorcycle Riding Experience

EAST TROY, Wis. (July 8, 2007) – For 25 years, Erik Buell has worked to apply intuitive, innovative design with the single goal of enhancing the motorcycle riding experience. A Buell motorcycle is first and foremost a great-handling machine that responds immediately and accurately to rider input.

The Buell design philosophy is expressed in a set of core engineering principles that have been a guiding force at Buell since the very beginning of the company.

The Buell Trilogy of Tech

Chassis Rigidity: The aluminum frame, front fork, rear swing arm and even the engine (as a stressed member of the frame) are each designed to contribute to unparalleled chassis stiffness. Limiting flex throughout the chassis results in outstanding steering precision and enhances rider confidence and control. The Buell Intuitive Response Chassis (IRC) is centered on a frame that is designed to withstand extreme torsional loads. The IRC designed for the new Buell 1125R is the stiffest chassis ever offered by Buell.

Mass Centralization: The motorcycle's center of mass is located as low as possible and centralized within the chassis to make quick directional changes seem effortless. For example, the muffler is located below the engine and centrally between the wheels, rather than the high-and-aft position typical of most sportbikes. Fuel is carried within the hollow spars of the aluminum frame, rather than high on the motorcycle in a traditional fuel tank. On Buell XB models, the swing arm doubles as the engine oil reservoir. The longitudinal radiators on the new Buell 1125R place the weight of those components closer to the motorcycle's center of mass. The result is a motorcycle that feels intuitively responsive to rider input.

Low Unsprung Weight: Minimizing the mass inertia or weight of every component not supported by the motorcycle's suspension helps the tires stay in contact over changing road surfaces. It also reduces the rotational inertia of the wheels, cutting the gyroscopic effect and contributing to handling response. Buell was the first to introduce upside-down (inverted) forks on a production motorcycle in 1991. The new Buell Zero Torsional Load (ZTL2) front braking system, mounts a single 375 mm rotor near the wheel rim, gripped by an eight-piston caliper. The large-diameter rotor provides exceptional stopping power without the weight of dual rotors and calipers. Because braking forces are transmitted directly from the rim to the rotor, torsional load acting on the rest of the wheel is virtually eliminated. This permits the use of a very lightweight front wheel that also helps reduce steering inertia. The entire Buell XB wheel, brake, tire and axle assembly, for example, weighs 24.5 pounds, or 6.8 pounds less than the same components on a competitive Supersport 600-class motorcycle. On the new Buell 1125R, the rear brake caliper is mounted directly to the inside of the cast-aluminum swing arm, a design that saves another pound of unsprung weight.

Buell Multifunctional Design
Weight is often reduced when a single part can be designed to accomplish more than one task. The concept of multifunctional design is used whenever possible in Buell motorcycles, which have roughly 50 percent fewer parts than competitive sportbikes, and are thus also less complex. The prime example of Buell Multifunctional Design is the use of the frame as a fuel reservoir. Another is mounting the Buell 1125R rear brake caliper directly to the swing arm.

Buell Immediate Throttle Response System
To eliminate driveline lash and hesitation, the Buell Immediate Throttle Response System features an idler pulley that keeps the secondary drive tension constant as the rear wheel moves up and down through its suspension travel. The Goodyear Hibrex final drive belt with Flexten Plus technology used on all Buell models weighs just 1.06 pounds, compared to drive chains that weigh four to five pounds, making another significant contribution to minimizing unsprung weight. The drive belt is also incredibly strong, and requires no lubrication, scheduled service or replacement.

Buell Powertrain Philosophy
Buell understands that in most street-riding situations, abundant torque and a wide powerband are more satisfying and functional to the rider than peak horsepower. Buell V-Twin engines are designed with a broad, flat powerband that delivers loads of on-demand torque so the rider is not left waiting for rpm to rise or downshifting to get into the powerband. Buell V-Twin engines are compact and narrow in profile, another contributor to mass centralization. Buell DDFI 3 fuel injection delivers crisp throttle response in any riding situation. To enhance overall chassis rigidity, the engine is incorporated as a stressed member of the chassis.