rigidity. Buell engines were designed to be street-friendly both in fuel efficiency (up to with the Blast), and in torque (the 1,203 cc version produces ). They are also simple and easy to maintain. Most Buell two-cylinder engines utilize computer controlled ducted forced air cooling (variable speed fan that only activates as required), two valves per cylinder, a single throttle body, zero maintenance hydraulic valve actuation, and zero maintenance gear-driven cams. Buell advanced their 1190 platform significantly under the Erik Buell Racing tenure. Engine technology improved to the EV-V2 1190cc 72 degree V-Twin that produces 185 horsepower at 10,600 rpm and 102 ft. lbs. of torque at 8200 rpm. Buell models Tube-frame bikes (1984–2002) RW 750 Road Warrior (1984) The RW 750 was a development of the Barton Formula One racing motorcycle. Buell bought the parts and tooling from the failed Barton concern and developed the RW 750 for his own use and for sale to private entrants. The engine was a liquid-cooled two-stroke square four. Buell's development resulted in a more competitive racer, but production ceased when the AMA discontinued the Formula One class. RR 1000 Battletwin (1987–1988) The RR 1000 Battletwin was a street sportbike using a modified Road Warrior chassis and a Harley-Davidson XR1000 engine. Buell invented the Isoplanar engine mounting system to allow the heavy, vibration-prone engine to be used as a structural member of the frame without transmitting the engine vibrations to the frame. Lack of space caused Buell to put the suspension components under the engine. The linkage caused the spring and the shock absorber to extend when the wheel went up. Variations on the RR 1000 Battletwin include the RR 1200 Battletwin (1988–1990), the RS 1200 Westwind (1989), the RS 1200/5 Westwind (1990–1992) and the RSS 1200 Westwind (1991). S2 Thunderbolt (1994–1995) Two-seater with Road Warrior-based chassis and Sportster engine. The S2T Thunderbolt (1995–1996) was a touring version, with saddlebags. The S2 was very expensive to develop (around $100,000), and 1,399 units were sold in the first year—well over the 300 units Buell had projected. S1 Lightning (1996–1998) The S1 Lightning was a more fundamental sportbike than the S3 Thunderbolt and M2 Cyclone that it was marketed alongside and the production on this model was stopped at 5000 after only 3 years. Variants of this version of the Lightning were the S1 Lightning (1996/1997/1998) and the S1W White Lightning (1998). The S1W came