The so-called Triumph Quadrant (aka "Quadrent") was a "bitsa" designed and built in secret by Doug Hele in 1973.

[1] It was a 1,000 cc four-cylinder motorcycle made up from Trident parts (although the camshaft was sourced from outside the factory).

An inside view is that Hele's efforts in building the Quadrant was a waste of precious resources that (given NVT's precarious status) should have been directed elsewhere, such as getting the 900 cc triple "Thunderbird III" to market sooner.

[2] The National Motorcycle Museum in the UK and Roy Bacon, the author of "Triumph Twins and Triples", hold a different opinion of the Triumph Quadrant prototype than the above posting: TRIUMPH 4 CYLINDER 1000cc PROTOTYPE .....the Experimental Department under Doug Hele and based at Kitts Green, looked ahead for a successor (to the Trident) and built this interesting four cylinder prototype which just had to be nicknamed "The Quadrant".

The cylinder block, the head and camboxes were all produced in the same way, but the crankshaft was built up and the camshafts specially made and carried cams with mild timing.