You cannot overstate the impact of Edward Turner’s late 1937 Triumph Speed Twin.
No less a figure than Sir Malcolm Campbell, then three times World Land Speed record holder, in 1939 wrote: “In my opinion, the Triumph Speed Twin has no equal.”
A contemporary road test found that “much of the joy in driving the model… comes from the delightful way the machine will zoom from 30mph to 60, 70 or 80mph at the will of the rider without his having to touch any control other than the twistgrip.” They achieved a best-timed run, admittedly with the wind behind, of 107mph, “an amazing figure for a fully equipped 500.”
With all the adulation, it may be as well to remember that the Triumph twin’s debut had not been entirely trouble-free. The 1938 5T crankcases are unique, as the engine had to be redesigned for the following year with eight fixing studs at the cylinder/crankcase joint. Some of the first six stud batch had, as Turner’s then-assistant Bert Hopwood put it, “blown off their barrels.” But when later in life Hopwood was asked to name the ultimate British two-wheel design, he had generously chosen the Speed Twin.
Ivor Davies, Triumph’s
