Triumph Quadrant

The Triumph Quadrant was a secret prototype built by Doug Hele in 1973, a 1,000 cc four-cylinder motorcycle assembled from Trident parts, although its camshaft came from outside the factory. The fourth cylinder came from grafting on an extra middle crankcase unit, but because the primary chaincase and final drive sprocket could not be relocated, the cylinder protruded on the right-hand side of the bike. Its top speed was reputedly 125 mph. Why Hele built it is something of a mystery, since the lopsided machine could never have reached production to compete with Japanese rivals such as the Honda CB750 and Kawasaki Z1, and some saw it as a waste of resources that should have gone to the 900 cc triple Thunderbird III.