Thumbing the starter, the Speed Twin roars to life with a deep rumble. Here’s a stock exhaust that doesn’t make the motor sound like it’s been sucking helium. The 1,200cc engine is in the same state of tune as the Thruxton’s (low-inertia crank, high-compression ratio), but features a new clutch assembly with reduced rotating mass, magnesium cam covers, and lighter side covers that shed 5.5 pounds from the engine alone. Overall, the Speed Twin is an impressive 22 pounds lighter than the Thruxton. Let that sink in.