1. V-Twin


Without the V-Twin, American motorcycle production would almost cease to exist; all current models from Harley-Davidson, Indian (pictured) and Victory are only available with a V-Twin powerplant. Even though Ducati has recently been describing its engines as L-Twins in an attempt to distinguish them, they are simply 90-degree V-Twins rotated forward in their frames. Moto Guzzis also use 90-degree V-Twins, which have perfect primary balance as opposed to narrower-angle V-Twins. All the Japanese brands have V-Twins in their lineup, as does KTM, Aprilia and most defunct motorcycle manufacturers. The V-Twin configuration is arguably the best combination of aesthetics, economy, sound, and performance.