S1 Lightning was faster and lighter than the others but had a very narrow seat. The S3 Thunderbolt was a touring bike that had a wider seat and more comfortable riding position, but was also heavier. The M2 Cyclone filled the gap between the sport and touring models with a bigger seat than the S1 Lightning and lighter and faster than the S3 Thunderbolt. The M2 was only available with the 1,203 cc engine and five-speed transmission. The frame was tubular CrMo steel. Blast (2000–2009) The Blast was Buell's only model to use a single-cylinder engine. With displacement and dry weight, it was their smallest model, often used in Harley-Davidson's "Rider's Edge" new rider instruction/riding schools. This filled Harley CEO Jeff Bleustein's idea of having a make-specific training bike, since many students end up buying a bike from the dealer where they trained. The Blast came from a quick proof-of-concept at the Buell factory. It originally used half of a Sportster 883 engine. The engine ended up 80 percent over budget and very expensive compared to the higher-technology Rotax engines available from outside the company. Cycle World wrote "Such an overrun would be unheard of from an outside supplier, but when your supplier also owns you, you grin and bear it." The Blast was ultimately the most expensive development project Buell undertook. Because the engine was overpriced, it ended up making money for Harley while losing money for Buell. It was regarded as a technical success. In July 2009, Buell ran an ad campaign stating that the Blast would no longer appear in their line-up. The ad showed a Buell Blast being destroyed in an automobile crusher. XB-series (2003–2010) 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 , but the Aerocharger supplier deal fell through when Harley-Davidson decided to engineer one 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 of $7,995 to $9,995. It was a popular bike, but never sold at Harley marketing department's expected volume, partly due to the significantly higher price. Buell introduced the