There are masses of books on this subject written by all and sundry most of which they got out of the Green un and the Blue un, no one ever got the chance to interview Turner himself as no one at the time was in the slightest bothered, he died when his twin was still being produced although he retired in 1963. Those who really knew him included the late Jack Wickes, and Hughie Hancox is who still fettling Triumphs.
I read from a Classic Bike dated 1993 recently that the first Triumph twin was a parallel side valve in 1913, the Great War intervened and the twin shelved until 1933 when Val Page produced the 650cc ohv with semi unit gearbox. Page must be considered the father of the parallel twin but it took Turner's expertise to evolve the rather overweight design into a sales winner.
The article goes on some more at length. The above of course is true, up to a point, Page did design the model 6/1 and it was so good you never see any, when I enquired about this lack of survivors my friends rolled in mirth as they said its crankshaft was related to the one in the Austin Seven, my blank look gave forth more merriment as they explained the crankshaft was made from a large paper clip, what they meant was flimsy.
The statement in CB also leads the unwary to believe that Turner rehashed the model 6/1 or that is what I take the word 'evolve' to mean and that is'nt true at all, Turner never copied anyone other than Chevrolet when he needed to know what a crankshaft looked like for his V8.
The truth of Turner's original Speed Twin started in the late 1920's. Turner had a one man shop in somewhere like Fulham, he dreamt up a design for a compact ohc with unit construction four cylinder engine and hawked it around the British industry, the world was in the depths of the worst depression this century and many manufacturers went to the wall, those that survived did so with utilitarian low priced machines, no one wanted to embark on a costly new design. Except Jack Sangster at Ariel who gave Turner a small office and the services of a junior draughtsman, the draughtsman was Jack Wickes.
This was 1928 and Turner had his prototype up and running in quick time, however when it was on bench testing Turner had a 360' crankshaft made up and fitted this into the rear of his Square Four and left the coupling gear to the front crank off, hey presto Turner was running a parallel twin; and looking over his shoulder was Ariel's chief designer Val Page.
Page then left Ariel and went to Triumph, back at Ariel Turner took over the hot seat and rehashed the entire range including a 4 valve Red Hunter, those designs where effectively the last four strokes from Ariel and their pre war reputation as sporting machines was well earned, like his four they lasted until 1959.
In mid 1936, Turner fell out with Sangster and went to Triumph, Page saw him coming and went back to Ariel. Turner again set about reshaping the Triumph range, all singles except the 6/1 and the Tiger 70, 80 and 90 appeared of 250, 350 and 500cc respectively, the numbers denoted their claimed maximum speeds, they are particularly attractive machines, Turner also went back to his twin concept, the model 6/1 had been dropped and the time was ripe for another new concept in the Turner mould.
Speed Twin made it in the September of 1937 in time for the 1938 season, amazing that this man could turn out an entirely new design and get it right first time in so short a time, they don't do it today and judging by recall figures they don't always get it right either.
The original Speed Twin had a 6 stud engine and was road tested by the magazines of the day to have a mean maximum of 94mph and an astounding 107mph quarter mile was timed, this was a tourer and it was beating the hot sportsters of the day hands down.
For the following season a more sporting machine was envisaged and the engine was given 8 studs to hold it together, privateers had been busy supercharging the early Speed Twins and the lightweight construction of the 6 stud motor had shown its inability to sustain power increase. The new machine was given the title Tiger 100 again to denote its speed abilities and was a winner from the start, just as that got going the war intervened and there the matter rested.
Speed Twin could hold its own against anything from anyone, and Tiger 100 had them beaten, Turner was obsessed with weight saving and castings where weighed before and after machining, yet fragility was never a shortcoming with them, nor as time has proven their ability to keep on going on.
Whilst scanning the older mags for info I came across the road test for the superb Gilera Saturno of 1946 and the typically 'we do it our way' Guzzi Falcone Sport of 1952, both have much the same perfomance but at 85mph they are well down on Speed Twin and not even in the same dimension as Tiger 100.
Turner's twin had stolen a march on the others, it was light, easier to start and more flexible, the bit about higher rpm's being available with the twin where as valid then as they are today.
Turner himself never thought of his creation as a racer, in fact he did everything he could to dissuade people from racing them, even to the point of catching 2 employees supercharging their own bike so he stood there whilst they smashed it with sledgehammers. However he had no control over privateers and they where racing them, hence the factory was coerced into making available parts, again Turner did his upmost to discourage these ventures, he knew better than anyone that the design was never stressed for racing, that it did only pays the man more compliments.
During the war Triumph where bombed out and the move to Meriden was made, military twin production was undertaken with the 350cc model 3T they also had contracts for portable generator sets for aircraft use and for these square alloy barrels where made, as soon as the war stopped the privateers got hold of surplus barrels and fitted them to Tiger 100's, Triumph made them a close ratio box and a new cam was fitted to the inlet which together with larger valves improved their already impressive performance, the Triumph GP model was born.
It won the first post war Manx GP against factory oposition in the form of 1939 racers dragged out of cellars, it also won Daytona in 1950 and the Americans where clamouring for more. In 1950 the supply of war surplus alloy barrels ran out and the GP model was dropped leaving only the standard Tiger 100 for the racers to buy, pressure was applied to the factory in no small way by American's and the upshot was that Turner designed a new close finned alloy barrel and had them die cast but he would not budge in that the factory would never again be involved in supplying racers, what he did do however was to initiate tuning kits that you could buy to tune your Tiger.
Even so the close ratio gearbox and light alloy mudguards where still listed extra's, the last fling came in 1953 with the one year only Tiger 100C. This was a Tiger 100 with the race kit already fitted although it retained silencers and not open megaphones, only 560 of the Tiger 100C's where made and then things changed.
The US market in particular was and still is obsessed with size, no matter that a Speed Twin would run rings around the Harleys and Indians of the day they wanted bigger engines, and in 1949 Turner had given the world Thunderbird, an evocatively named 650cc twin, again a low compression tourer, it was a success from the word go particularly with the sidecar boys who needed big grunty motors and all they had where rattly snatchy old V twins. In 1954 the rigid frame of the Triumphs gave way to technological improvement and the swingarm frames where introduced along with a hot 650 known as the Tiger 110, the days of the Tiger 100 as their top of the range sports machine was all but over, Turner was'nt interested in racing so the 500cc class did inceasingly without. The kits had stopped also so Tiger tuning became the passtime of many a private workshop.
In 1958 Triumph launched a twin carb Tiger 110 and renamed it Bonnieville after the success on the salt flats with what was really a Thunderbird engine tuned and aside from the introduction of the new unit construction 3T Twentyone in 1957 followed by the unit Tiger 100 and the 650's in 1962 there the matter ended.
Bert Hopwood who had designed the Norton twin in 47 took over at Triumph, Hele joined him when Norton's closed down in 63 and together the did improve Triumphs legendary handling, they also knocked more power out of them but effectively the game was over.
Hopwood along with Hele did use one and a half Tiger 100's to produce the prototype Triple but that was put on the back burner until it was far to late and in the 70's the factory closed. Turner's old twin however lived on until 1988 when the last Bonnieville left the Harris factory at Newton Abbott in Devonshire by then a poor thing by comparrison to its forbears but that engine did see 51 years of production and always managed to hold its head up, if you see a bad Triumph twin and I certainly have then don't blame the bike blame the owner, because there is no excuse valid for a poor one all parts are available and easy to get.
My thanks go to Hughie Hancox for his insight into how Turner ticked. I have read a lot about Turner, I have him at Brooklands sitting in a sidecar and accusing a tester of malingering because he had stopped, the pool of oil under the stationery machine not counting as an excuse, I also have him sat in a limo and remarking to the driver why it was the car went faster in the reverse direction than when they went, he did'nt figure the wind assistance, nowhere can I find Turner ever having ridden a bike, this could explain the handling, he was obsessed with style at any expense and spindly fork stanchions and flimsy frames look good, in my own experience of the bikes you learn to live with the handling, well you either learn or supply parts for another Triton.
One other point for the pernickety, those 1951 tuning kits marked the first appearance in the parts list of the E3134 inlet camshaft, Hughie states that the E3134 was the same cam that had been used in the GP model which dates E3134 back to 1946 and not Bonnies launch as many people ( me included ) had supposed, hence Bonnie was not the all singing all dancing machine the scribes would have you believe but in reality what I've always been told, a twin carb Ton Ten of which the US market had already had the splayed head and carbs, the only other mod of note was the introduction of the 9 stud engine as heads where found to be cracking on the Ton Ten following the switch from iron to alloy.
The switch from iron heads to alloy for the Tiger 100 had also introduced to the discerning noisy valve gear, this was cured in part by the introduction of cams with quietening curves, engines fitted with 'ramp' cams have a small compass like wheel mark after their engine numbers, the iron engines mechanically speaking are as quiet as the grave.
So at the outset back in 1937, Turner created a twin that was no wider than the singles, weighed in at 5lbs less and cost 5 pounds more, the bike was born into a world of recession and political instability, it went racing, world record holding and at 20 years of age became the first production motorcycle to crack the ton lap where it mattered. It was designed for people with a very limited budget and it had to be user friendly from the maintenance standpoint. None of the latter constraints apply to machines of equivalent specification today, during its lifespan it saw the introduction of shell bearings, many tell me they recall the Ferrari running around the tracks labeled 'Thinwall Special' run by Vandervell Bearings who later made their own very successful racer the Vanwall, larger diameter mains where added and it trickled along very nicely and gave countless thousands pleasure, indeed thousands are still getting pleasure from their 60 year old twin. If success were measured by longevity Triumph are still world beaters.
I stand by my friends in their viewpoint of the older Triumphs are better, true the 65 model year was the first with good handling and by 68 they handled on a par with anything else, but they where losing their styling edge and the quality of bought-in components like carbs and electrics was becoming iffy in the quest to cut costs and maximise profit, I have seen US spec machines with some wonderful batteryless ignition systems fitted and wondered just what kind of people would chuck a battery down the loo to save weight and then have huge high bars that stop you going fast, but that US ignition narrowed the amount of automatic advance and retard the engine has so US spec machines must all be lumpy brutes at low revs, I know this from the experience of my machines manual advance/retard, if you don't retard them they run lumpy and the ton ten needs retard by the time the speeds down to 40 to get the best from it.
Turner's styling was his own work, many attribute it to Jack Wickes who was responsible for the post 65 tank badges, but Jack said Turner always gave him a rough sketch to work from, he just put the meat on the bone.
Good job I don't own a Norton innit :-)
[Some very minor edits were made to this article, fixing obvious spelling errors and adding the odd comma and fullstop. No information on who AH is or how Sheldon came by this piece. Ed.]