Monster-torque

" The XB1203 engine is the same physical size as the XB984 engine, so it offers an even better torque-to-weight ratio. High-flow heads and lightweight valve train give the engine crisp throttle response, but power delivery is smooth and steady, thanks to the engine's broad torque band, Buell InterActive Exhaust, and snatch-free belt drive. "With the engine in the Firebolt XB12R, we offer power that will satisfy the most demanding sport rider. Not just peak horsepower, but the kind of ground-pounding, mid-range torque you can use to accelerate instantly in any situation."

Buell Motorcycles introduced a whole new category of motorcycles with the launch of the 2003 Buell Firebolt XB9R: the original Sport Fighter. True to the Buell tradition of building Street Fighter motorcycles, the Firebolt XB12R features aggressive styling with minimalist bikini fairing, an exposed V-Twin engine full of character and enormous amounts of torque, and above all, delivers a great riding experience on real roads. The Buell Firebolt is designed to appeal to experienced riders used to sport bikes but now looking for a motorcycle that has performance they can enjoy in the real world every day. Not lap times but the emotion and pleasure of you and your Firebolt beating a twisty road into submission.

Premium components. Razor-sharp reflexes. A bottomless supply of torque. The Buell Firebolt XB12R is built to dominate your favourite roads. The 1203cc engine - Tuned For Torque The heart of the Buell Firebolt XB12R is its XB1203 engine - a 1203cc light-weight 45-degree, air/oil/fan cooled, fuel-injected V-Twin based on the 984cc engine that debuted in the Firebolt XB9R. The XB12R engine achieves its displacement boost through an increase in stroke, from 3.125 inches to 3.812 inches.

The engine has a bore of 3.500 inches. The compression ratio is 10:1. To further broaden its torque band, the 1203cc engine is equipped with Buell InterActive Exhaust. An electronic actuator activates a butterfly valve housed in the muffler to adjust back-pressure by alternating between two gas flow paths. The engine ECM monitors engine speed and throttle position while activating the valve to optimise torque and horsepower for the riding condition. At wide-open throttle, for example, the valve is opened at low rpm to reduce back-pressure so the engine can gain rpm quickly. The valve closes in the mid-range to increase acceleration torque, and then opens again at high rpm to maximize horsepower.

The Buell InterActive Exhaust System brings out the rich, throaty rumble of the Firebolt exhaust tone. The header pipe diameter is 1.75 inches and the intake throttle body diameter is 49mm. All this enables the Buell Firebolt XB12R to pump out 100 hp (74.6kW)* and 81 ft. lbs. (109.7Nm)* of torque. (Australian specifications may differ). A stiffer clutch spring and 14mm pitch aramid reinforced Hibrex belt with Flexten Plus technology are fitted to handle the torque demands of the 1203cc engine. ( Hibrex and Flexten are registered trademarks of the Goodyear Tire & Rubber Company.)

Significant developmental efforts have been put forth in producing great torque over a broad rpm band. This effort began with the development of a zero loss intake system and very exhaustive research to obtain the best intake/exhaust tuning. It also found application in the new, high flow, head shape and the profile of the camshafts, with less overlap for an optimum mid-range power. The lightweight valve train includes smaller diameter valves and ensures higher rpm stability. The algorithm of the Dynamic Digital Fuel Injection has been redefined to achieve the torque, smoothness and driveability objectives of the development team, all signature of the overall XB concept.

The 1203cc engine includes an oiling circuit similar to the Harley-Davidson Twin Cam 88, with piston oil jets. The engine also features a reed valve that pulls oil from the cylinder head thereby reducing oil carry-over to the air box. The use of piston jets and oil cooler, combine with a state of the art forced air flow that includes a high flow fan cooler and wind tunnel developed air flow control channel around the engine, drastically reduces the oil temperature in any condition. With the addition of large fin cylinder and cylinder heads, the simplicity and compactness of the engines is enhanced while ensuring very well controlled engine temperature.

Bodywork The minimalist Firebolt body parts are made of Surlyn moulded-in-colour plastics. Developed in relationship with Dupont de Nemours, they use a strong, flexible material. The colour is moulded into the bodywork during the casting stage, giving the bike a finer finish and avoiding defects associated with a conventional painting process. In the event of a minor spill, blemishes can be polished out of this material.

Electrical / Dashboard The XB engine features a three-phase high output alternator. The Buell Firebolt's forced-air cooling system involves an ECM (Electronic Control module) controlled fan. The dashboard includes the speedometer, tachometer, indicator lights, low fuel warning indicator, two trip odometers, one fuel odometer which starts to count mileage when the low fuel light goes on, and a clock. Storage A small storage space is provided under the pillion seat to store a small anti-theft device or some personal belongings. It is accessed through the keyhole located beneath the tail section.