The BSA Lightning was designed as the all-round sports machine of the 1960's, planned largely for export to the US market to complement the touring Thunderbolt and the later development, the supersports Spitfire. Development of the engine aimed to make it more reliable, quieter and less prone to oil leaks, with top speed sacrificed to improve mid-range and rideability. Nevertheless, with twin carburetors the A65L could still reach 108 mph (174 km/h).