Buell XB12S - 2005

The neighbourhood just got tougher. With the introduction of the Buell Lightning XB12S, Buell has taken Streetfighter motorcycles to a the extreme. The XB12S offers a different level of brute, naked performance, a volatile blend of dirt track attitude and the latest technology powered by a XB1203 V-Twin engine tuned to pound out a mountain of torque. From its flyscreen to its chopped-off tail, the Lightning XB12S sets the standard for streetfighter attitude.

Designed in the spirit of the original American streetfighter, the 1995 Buell Lighting S1, the Lightning XB12S, offers upright ergonomics, uncompromised agility and a big, rowdy engine that puts out the kind of power street riders lust for; 100 hp (74.6kW)* and 81 ft. lbs. (109.7Nm)* torque. The Lightning XB12S captures the soul, spirit, emotions of the S1 and combines them with the radical, modern technology of the highly acclaimed Buell Firebolt XB12R.

"The Lightning XB9S was our small-block bike. It's engine is quick, snappy and revhappy," said Erik Buell, chairman and chief technical officer at Buell Motorcycle Company. "The new Lightning XB12S is like ordering the hot, big-block version of the same motorcycle. You get classic V-Twin torque. The XB12S is just as agile and sophisticated as the XB9S, but the power is almost brutal."

The Lightning XB12S is designed to excel in the cut-and-thrust world of urban streets and aggressive, back-road twisties. Start with an ultra-short 52-inch (1320mm) wheelbase and 21-degree fork angle. Wide, flat handlebars maximize rider input in the turns. The massive aluminium frame and swingarm are designed to provide exceptional chassis rigidity, and both do double-duty. The frame carries 14 litres (3.7 gallons) of fuel, while the swingarm acts as the engine oil reservoir. In each case, this helps lower the bike's overall centre of gravity. The muffler is located below the engine for the same reason. The result is a motorcycle that's willing to change direction the instant rider input occurs.

Stopping power is provided courtesy of the Buell Zero Torsional Load (ZTL) front brake system that mounts a 375mm rotor near the wheel rim, rather than on the hub. Gripped by a six-piston caliper, braking forces are transferred optimally to the rim, virtually eliminating torsional load on the front wheel. Braking response and feel are outstanding, and a very lightweight, six-spoke cast aluminium wheel reduces unsprung weight and steering inertia. The front is supported by a fully adjustable 43mm Showa upside-down fork.

The Lightning XB12S is targeted towards sport bike riders worldwide, looking for a premium motorcycle designed for the real world. They are experienced riders, who have owned already one, or several sport bikes. They understand the limits of the race-replica style, but still want to own a motorcycle that allows for and rewards athletic riding. They understand that handling, agility, and acceleration are more important in real world situations than maximum horsepower. They embrace the vision that look, sound and feel, in one word "character", is one of the most important dimensions of a motorcycles appeal. They are passionate about motorcycling and their motorcycle is an expression of their personality, taste, and attitude. They appreciate and enjoy attention to detail, premium components, smart technical solutions and innovation.

Engine

A Torque-monster 1203cc V-Twin powers the Lightning Streetfighter The Buell Lightning XB1203 engine is a fuel-injected 45-degree, air/oil/fan cooled, fuel-injected V-Twin. The engine is based on the XB984 engine from the Buell Lightning XB9S, stroked from 3.125 inches to 3.812 inches to achieve a new displacement of 1203cc. The bore remains 3.500 inches, and the compression ratio is 10:1. The intake throttle body diameter is 49mm.

To keep the torque band fat, 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 Lightning exhaust tone. The header pipe diameter is 1.75 inches and the intake throttle body diameter is 49mm. All this enables the XB12S to pump out 100 hp (74.6kW)* and 81 ft. lbs. (109.7Nm)* of torque. (Australian specifications may differ). The XB12S engine 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.

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. This 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 XB12S 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 Lightning engine. 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 Lightning performance and technology are not enough to make its rider the centre of attention, its styling will finish the job. The XB12S features a dirt track race inspired flyscreen, combined with a classic round-tube handlebar and an ultra short aluminium tail section all creating the unique Streetfighter look and attitude. The XB12S is now available in three colours, with the new Thrust Blue added to Midnight Black or Racing Red option, all offsetting the Graphite Grey frame and swingarm, as well as translucent amber wheels. The ventilated tail section is magnesium tone and polished alloy, while the same magnesium tone is used on the primary cover, cam cover and front module.

Michael Samarzja, Buell's Styling Director explains the Lightning's design: "The goal for the design team in styling the Lightning was to capture the heritage of the S1, S1W and X1 in the flavour of the new XB chassis. We wanted all the aggression of the ultra short S1, the original Buell Streetfighter. We wanted the signature cast tailsection of the X1. The first styled/structural cast bodywork on a motorcycle. And we wanted the technical advantages of the new XB chassis. Short, rigid, narrow, light. Downdraft fuel injection with no airbox on the side of the bike. Density - wheels, a motor and a place to sit. Broad-shouldered and muscular. A modern day flat track racer for the street."

The Trilogy of Technology

The Lightning XB12S along with the 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 both Lightning models 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 on the XB12S 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 Lightning 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 Lightning 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 Lightning XB12S 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 tire 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 Lightning features an asymmetrical and minimal front flyscreen resembling a number plate mounted over small, efficient dual headlights stuffed tight into the front end and held by a beautiful casting integrating all the components together. The key is located to the left side of the casting and new high contrast and visibility gauge graphics with superior night visibility include an accentuated tachometer. The ultra short cast aluminium tail section with it's signature Buell upswept line is aggressive, extremely light and minimal, leading the eye to the signature tailpiece. Painted in Black Chrome powdercoat, it matches to the front module casting. New tooling processes provide a beautiful surface finish.

Ergonomics

The ergonomics of the Lightning are radically different from those of the Firebolt. The handlebar, seat and footpegs location redefine the riding position, to achieve a true Streetfighter feel combined with a perfect sense of control. The front end of the motorcycle is so short, that the bike totally disappears when riding, giving a feeling of flight. These unique characteristics further reinforce the sensation of being directly connected with the road.

The bike is very narrow and extraordinarily agile, thanks to its low overall weight, incredible level of mass centralization, short wheelbase and the increased lever provided by the wide handlebar. The rigidity of the chassis ensures perfect stability and an immediate, unfiltered response to rider inputs. The relaxed riding position and the comfortable seat allow hours and hours of unlimited fun.

Bodywork

The ultra minimalist Lightning body parts are made of Surlyn molded-in-color plastics for better surface finish and scratch resistance. The XB12S is available in Midnight Black, Racing Red and Thrust Blue

Electrical/Dashboard

The XB engine features a three-phase high output alternator. The forced-air cooling system involves an ECM (Electronic Control module) controlled fan. The Lightning dash board, inspired by classic American hot-rod components features 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.

Quality/Development Process

In 2000, Buell put in place a whole new Development Process. The Lightning XB12S model has been developed following this Process which consists of 4 phases:

Technical Specification:

Colours