The 2005 Buell Firebolt XB12R

Designed to deliver handling and performance that will satisfy the most demanding sport-riders, the 2005 Buell Firebolt XB12R motorcycle combines technological brilliance and American V-Twin power.

To flick a Buell Firebolt down a rural backroad is to experience handling so responsive it's almost intuitive. Twist the throttle and feel all the torquey, mid-range muscle you need to power out of turns or blast away from traffic.

The XB12R packs a 1203cc air/oil/fan cooled V-Twin torque-monster engine rated at 100hp (74.6kW)* and 81 ft. lbs. (109.7Nm)* of tyre-twisting torque. "We developed the ultimate sportbike architecture around the Firebolt XB9R," said Erik Buell, Chairman and Chief Technical Officer at Buell Motorcycle Company. " 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.

Engine

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. The XB12R also features a compensated clutch that enhances the overall transmission smoothness, improves traction and reduces the clutch lever effort by using a new, lower spring rate.

The charging system is made of a 3 phase "Trident" unit that provides a significantly higher output, out of a minimal inertia design. The XB intake system features a high volume air box with a high flow filter. The entire volume above the engine is available for this intake system thanks to the fuel location in the frame. The XB also features a downdraft Ram Air intake that increases airflow and power at high speeds. The muffler is installed underneath the engine in order to lower the centre of gravity and to centralise masses. The muffler features a very large volume for maximum performance.

The XB exhaust system also features a high velocity header with computer developed staggered length primary tubes for optimum mid-range power and torque. Any technical description would be incomplete without talking about the character of the Buell Firebolt engines. This very unique, inimitable Buell characteristic is a subtle combination of look, sound and feel: The feel resulting from the high torque push and the perfectly filtered but perceivable low frequency vibration that best provides the feeling of force. The sound, which is enhanced by the very modern engine technology that significantly reduces mechanical noises and allows a good exhaust note. The look of a unique, marvellous, simple, aluminium piece of art.

Styling and Colour options

If Firebolt performance and technology are not enough to make its rider the centre of attention, its styling will finish the job. The XB12R is available in 3 colours; Midnight Black, Racing Red, and new for 2005, Thrust Blue. All models feature a graphite-grey frame and swingarm, black-and-amber, tail and airbox graphics, magnesium tone chin spoiler and clutch and cam covers, and a wild amber windscreen. The cast aluminium wheels receive an exclusive, high-gloss translucent paint process that produces a beautiful amber colour with natural variations and depth. The perforated seat cover completes the premium look.

The Trilogy of Technology

The Buell Firebolt XB12R is the latest expression of the Buell Trilogy of Tech design philosophy, focused on three elements: frame rigidity, mass centralization, and low unsprung weight.

The rigid aluminium frame is a light-weight, multi-functional structure that serves as both a solid backbone for the motorcycle and as a 14 litre (3.7 gallon) fuel reservoir. Using the frame to carry fuel significantly lowers the centre of gravity and reduces the moment of inertia, both of which improve the bike's reaction to rider input. Mass centralization and a centre of gravity are further enhanced by locating the muffler below the engine. The massive aluminium swingarm doubles as the engine oil reservoir, and is supported by an adjustable Showa shock absorber.

The Buell Zero Torsional Load (ZTL) front brake system feeds braking forces from a six-piston caliper through a 375mm inside-out rotor mounted near the wheel rim to virtually eliminate torsional loads to the front wheel. This permits the use of a lightweight, six-spoke cast aluminium wheel that significantly reduces unsprung weight and steering inertia. The front end is suspended by a fully adjustable 43mm Showa inverted fork.

The final key to the uncanny agility of the Buell Firebolt is a chassis geometry that combines a 21-degree fork angle and 83mm of trail with a compact, 52-inch (1320mm) wheelbase. Fifty-two percent of the bike's mass is carried on the front wheel. The result is a sport motorcycle with the quick reflexes of a GP racer, a bike that will flick into a corner instantly and hold a line that other sportbikes can't touch.

Belt Drive

The Buell belt drive features an additional idler pulley that ensures a constant path length of the belt. All the well-known advantages of a belt drive, such as smoothness, durability and maintenance ease, are enhanced with this new configuration. However, the most significant advantage of this new technology is the total absence of any lash in the transmission thus optimising power control. Furthermore, the constant belt geometry limits the influence of the secondary transmission to the rear suspension. No adjustment is required, which simplifies maintenance and reduces the number of parts and the weight of the rear axle assembly. 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.)

Frame

The Buell chassis includes a multifunctional aluminium frame. This masterpiece blends the functions of a traditional frame with a fuel tank. Its massive construction delivers an exceptional level of rigidity. The fuel is located in the bottom-end of the frame and therefore located much lower and more centred than on a traditionally configured bike. This lowers the centre of gravity and reduces the moment of inertia in pitch and roll. The overall weight of the frame is significantly lower than the weight of the traditional components that it replaces.

The Buell Firebolt also features the Buell patented Uniplanar system which allows the engine to participate in the frame rigidity AND filters most of the engine vibrations. The Firebolt frame is proudly showcased and exposed as a key styling element of the motorcycle.

The overall Firebolt chassis dimensions are as outstanding as the ones of a GP racer: 52 inch (1320 mm) wheelbase, 21 degree forks angle, 83 mm trail and 52% of the motorcycle weight rests on the front wheel. These exceptional specifications are made possible by a number of factors: The frame and chassis rigidity, the very low steer axis inertia, the position of the centre of gravity and the unique, very short configuration of the engine. And the aim remains the same: A very intuitive, natural motorcycle to ride through the twisties.

Swingarm

As per the frame, the swingarm is made of aluminium. A massive piece further enhancing the rigidity of the chassis. It forms, with the frame, this one line shape. When looked at from the left-hand side of the bike, it constitutes a line from the steering head to the rear wheel axle. And again, form meets functionality as the swingarm holds the oil reservoir around the arm pivot. This not only reduces the number of parts and the weight of the motorcycle, it also helps reduce the overall size of the bike by allowing for an easier packaging of elements such as the battery or the DDFI II electronic module. This perpetuates Buell's strength in delivering bikes with mass centralisation and a low centre of gravity.

ZTL Front disc brake / Rear brake

The Buell Firebolt XB12R features an innovative front brake composed of a 375 mm inside-out brake rotor combined with a six piston caliper. This configuration provides exceptional braking power and an excellent "feel" and "feedback" to the rider, while dramatically reducing the front un-sprung weight. The new Zero Torsional Load (ZTL) brake transfers the braking forces optimally from the rotor to the end of the spokes rim, without applying any significant torsion load to the spoke of the front wheel, allowing for the lightweight wheel design. The rear brake has also been optimised to ensure the proper balance between power and control.

Suspension

The fully adjustable Showa inverted forks ensure maximum rigidity and feedback. When combined with the optimised triple clamp and front wheel axle design, the result is an outstanding front-end rigidity. The forks' set-up delivers fantastic steering accuracy, while maintaining an excellent level of comfort and feedback to the rider. It is like having the front wheel mounted between the rider's thumbs! The rear suspension is made of a fully adjustable Showa rear shock absorber, directly installed between the frame and the swingarm in a semi-vertical position, allowing such a short wheelbase.

Wheels

Thanks to the front brake configuration and wheel design optimisation, the weight of the front wheel assembly has been reduced to an incredible value. In fact, the engineering team simplified all components in the front wheel area as a result of its constant pursuit of weight reduction. An example of this minimalist approach is the front wheel axle configuration, which includes a minimum number of parts (no spacer, nut, nor washer) while assuring the highest level of rigidity. And benefits are evident: The low un-sprung weight ensures that the tyre has contact with the road surface in any circumstances, while the low steering inertia is a key element for the bike's impressive agility.

The rear wheel also benefited from the engineering initiative of weight reduction among the un-sprung elements of the motorcycle. The rear tyre size (180mm) has been carefully chosen to optimise the combination of traction and agility. The combination of front and rear wheel assemblies delivers optimal agility, traction, comfort, weight reduction, serviceability and .style!

Front module / Tail section

The thixatropic cast magnesium front module carries all the front-end accessories such as headlamp, instrument panel, electrical components and fairing. It is extremely rigid in order to avoid excessive vibration and is part of the overall weight reduction effort.

The sub frame tail section is made of square aluminium tubing and is bolted to the main frame for easy replacement. Its optimised structure ensures rigidity and weight saving.

Ergonomics

Intense scrutiny was exercised in the development of the handlebar-seat-footpegs triangle to optimise the balance between performance and rider control.

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.

Quality/Development Process

In 2000, Buell put in place a whole new Development Process. The Buell Firebolt XB12R model has been developed following this process which consists of 4 phases:

Technical Specification