Buell XBRR Racing Kit Manual (2007)

Buell introduced the XBRR in January 2006 as a limited-production, race-only motorcycle designated for the 2007 model year. Developed from the XB12R Firebolt platform, it aimed to provide privateer teams with a purpose-built racer for professional-level competition. It also recalled the company's beginnings with Erik Buell's RW750 racing motorcycle in 1983. Unlike the road-going Firebolt, this special machine was intended exclusively for closed-course use, with a small customer production run and race-oriented specifications.

The machine targeted the AMA Formula Xtreme category, which accommodated a large-capacity air-cooled pushrod twin against more highly tuned multi-cylinder competitors. Buell increased displacement to 1,339 cc with a 103.6 mm bore and approximately 79 mm stroke, retained a 45-degree cylinder angle and adopted a 12.5:1 compression ratio. The XBRR's factory supplement specifies 150 corrected rear-wheel horsepower at 8,000 rpm, dual 62 mm downdraft throttle bodies and DDFI III electronic injection. Its air-cooled engine and mass-centralized layout made it a distinctive limited-production Formula Xtreme racing motorcycle, not simply a standard XB12R fitted with racing bodywork.

Although the bike shared the XB platform's approach to frame and swingarm design, it differed in suspension, driveline and rolling equipment. Fuel was carried in the frame and engine oil in the swingarm, while race-specific Öhlins suspension and steering hardware supported circuit setup. Cast-magnesium wheels reduced rotating mass, and a 520-series chain replaced the Firebolt's final-drive belt so teams could choose gearing for each track. A wet multi-plate clutch worked with a five-speed close-ratio gearbox and straight-cut gears. The factory XBRR specification lists a 369 lb dry weight and a 4.40 US gallon fuel capacity, illustrating the bike's focus on competition.

Four XBRRs entered the 2006 Daytona 200 with dealer-backed teams, but mechanical trouble curtailed the debut. Engineering changes followed before customer production, including redesigned driveline parts, ignition-related components and a larger oil cooler. Contemporary reporting on Buell's 2006 XBRR production records those revisions. Erik Buell later described the race project and the technical rules that prompted it in a first-person historical account, emphasizing the opportunity to build a competitive air-cooled twin for specialist racers.

The XBRR is best understood as a specialized offshoot of the Firebolt rather than a successive generation of street-going XB motorcycles. It preceded Buell's later move to the liquid-cooled 1125 sportbike family but used fundamentally different engine architecture and racing equipment. The Buell Firebolt manual category provides related street-machine reference material. The 2007 XBRR document is explicitly a factory service supplement: it describes the race motorcycle's unique specifications and selected servicing, while referring readers to the separately published 2006 XB12R Service Manual (99493-06Y) for operations not included.