BSA Rocket 3/Triumph Trident adaptations only, available from the factory as part-numbered inventory. Williams' team won consecutive 750 cc production races at the Isle of Man TT for the five years between 1971 and 1975, and in the new F750 event for race-specification machines, Triumph and BSA machines with Rob North frames placed first and second. Bert Hopwood recommended a production version of the racing triple, producing at 8,250 rpm, but his suggestion was not adopted. Further racing development was done in Duarte, California under racing manager Dan Macias. Tom Mellor set four world speed records at the Bonneville Salt Flats in September 2008
Triumph Speed Four and other minor concessions to its streetfighter style; the frame and fully adjustable suspension are race-ready. The engine is a 599 cc inline-four-cylinder engine, as used in the TT600. The bike has a top speed of and a time of 4.5 seconds. "Motorcyclist" tested the 2002 Speed Four's time at 11.65 seconds @ and time at 3.71 seconds. The Speed Four was voted No.1 for handling and suspension in "Ride" magazine's 2008 Rider Power Survey. The Triumph Daytona 675 was second in the same category. Triumph UK After Sales has confirmed that 4,606 Speed Fours were produced from 2002 through