Buell introduced the XB frame in the 2002 XB9R Firebolt sportbike. The XB12R Firebolt was introduced in 2004 and was initially sold alongside the smaller displacement Firebolt XB9R.
The XB powertrain still had its roots with the Harley Sportster powertrain, and was designed for both projects. Unfortunately, it was designed by Harley with minimum input from Buell. A turbocharger was to be sourced from Aerocharger to help pump the XB horsepower to 150hp, but the Aerocharger supplier deal fell through and thus Buell began development of a turbo in-house. That project was a failure, despite "millions of dollars" spent.
Before the first XB was sold, the cost was well over the target, leading to a sales price increase from the original price point of $7995 to $9995. It was a popular bike, but never sold at Harley marketing departments expected volume, partly due to the significantly higher price.
