The Mk.I 'Black Bomber' was first shown in UK during the Diamond Jubilee Brighton Speed Trials of September 1965, traditionally held along the seafront. The bike was newly imported and its engine was not run-in, yet in a semi-competition demonstration sprint, the CB450, ridden by Allan Robinson (a Honda staff member), achieved a standing-start kilomer time of 30.1 seconds and a terminal speed of 100 mph (160 km/h).
The CB450 had excellent engineering for the time, including reliable electrical components, an electric starter, and a horizontally split crankcase, all features distinct from current British twins. A radical feature was the valve springing: instead of the conventional coil springs, it used torsion bars - rods of steel that twisted to provide the spring effect.
This original low mileage example shows light use and original low mileage.