Edward Turner tells the story
behind the new Triumph Terrier
behind the new Triumph Terrier
This interview with Edward Turner printed in 'The Motorcyclist' magazine in January of 1953 gives an insight into the thought process and design of the new Triumph Terrier. A machine that was built and undergoing tests within eight weeks of its conception by Turner.
Discussing his new machine Edward Turner said, "I decided on a 150cc high performance machine because world economic conditions seemed to be moving in a direction where the very high rate of production of our expensive motorcycles cannot be maintained, whereas I naturally wish to maintain the present productive capacity of the Triumph factory.
"Why a 150cc? Because in providing a lightweight machine which has no pretentions towards very high speeds on the roads, a modern 150cc ohv engine will give off ample power to propel a rider and pillion passenger, if necessary at a reasonable cruising speed with a maximum of 60 mph, which is quite adequate for the vast majority of motorcyclists.
"It is a 4-stroke because the limitations of a 2-stroke are too many for a real high quality machine particularly in regard to lubrication. For a given capacity I wanted to provide a machine that would give maximum possible power, together with long life, which in my view can only be done with a 4-stroke engine where the lower end, main bearing and big ends are positively lubricated by pressure.
"For a high quality motorcycle, even though it may be a lightweight, I am of the opinion that the extra cost of overhead valves, a timing gear and a proper dry sump lubrication system, in proportion to the cost of machine is on the whole well worth while. Also the other advantage of the 4-stroke engine is in absolutely certain starting with positive carburetion, auto advance and retard and the fact that you can usually silence a 4-stroke without loss of efficiency to a greater degree than is possible with a 2-stroke.
"We have produced a 4-speed gearbox (which we consider necessary with this small 4-stroke engine) with some highly original features, such as the gear operation, a frame which is fundamentally strong and yet inherently simple in theme, a gas tank which has the merits of the greatest possible capacity for the smallest bulk and weight, etc.
"All bearing surfaces, valve guide lengths, proportions of gears and hub bearings are of very substantial size, so that it is estimated that although this little machine will work a good deal harder that its big brothers it will be well up to the job and offer trouble-free and faultless service for al least the equivalent period.
"It has been thought desirable to enclose the battery with a proper built-in air cleaner which matches up with the oil tank as regards shape and form, to provide an extremely neat unit which has the advantage of being easily cleaned.
"There is a multiplate clutch having a cush-drive unit in its hub (now being use on larger machines in the Triumph range), a spring frame and a version of the highly successful A.C. electrical equipment with rectifier which will give a very good driving light and provide ignition independently of the battery. The contact breaker unit is very accessible and readily adjustable for variations in ignition timing.
"The front fork is almost identical in design with the bigger Triumph motorcycles, having a very handsome nacelle (which as regards shape is even an improvement) and in which is neatly mounted the switch, speedometer and electric horn.
"The braking is adequate, 5 1/2" by 1" brakes giving a ratio of area to weight in excess of that for a big machine, and also a very long life.
"As regards performance, this cannot be specifically stated other than that the first prototype when assembled exceeded 60 mph and it is hoped that this machine will be able to cruise very happily at 50 mph carrying rider with full equipment."
Discussing his new machine Edward Turner said, "I decided on a 150cc high performance machine because world economic conditions seemed to be moving in a direction where the very high rate of production of our expensive motorcycles cannot be maintained, whereas I naturally wish to maintain the present productive capacity of the Triumph factory.
"Why a 150cc? Because in providing a lightweight machine which has no pretentions towards very high speeds on the roads, a modern 150cc ohv engine will give off ample power to propel a rider and pillion passenger, if necessary at a reasonable cruising speed with a maximum of 60 mph, which is quite adequate for the vast majority of motorcyclists.
"It is a 4-stroke because the limitations of a 2-stroke are too many for a real high quality machine particularly in regard to lubrication. For a given capacity I wanted to provide a machine that would give maximum possible power, together with long life, which in my view can only be done with a 4-stroke engine where the lower end, main bearing and big ends are positively lubricated by pressure.
"For a high quality motorcycle, even though it may be a lightweight, I am of the opinion that the extra cost of overhead valves, a timing gear and a proper dry sump lubrication system, in proportion to the cost of machine is on the whole well worth while. Also the other advantage of the 4-stroke engine is in absolutely certain starting with positive carburetion, auto advance and retard and the fact that you can usually silence a 4-stroke without loss of efficiency to a greater degree than is possible with a 2-stroke.
"We have produced a 4-speed gearbox (which we consider necessary with this small 4-stroke engine) with some highly original features, such as the gear operation, a frame which is fundamentally strong and yet inherently simple in theme, a gas tank which has the merits of the greatest possible capacity for the smallest bulk and weight, etc.
"All bearing surfaces, valve guide lengths, proportions of gears and hub bearings are of very substantial size, so that it is estimated that although this little machine will work a good deal harder that its big brothers it will be well up to the job and offer trouble-free and faultless service for al least the equivalent period.
"It has been thought desirable to enclose the battery with a proper built-in air cleaner which matches up with the oil tank as regards shape and form, to provide an extremely neat unit which has the advantage of being easily cleaned.
"There is a multiplate clutch having a cush-drive unit in its hub (now being use on larger machines in the Triumph range), a spring frame and a version of the highly successful A.C. electrical equipment with rectifier which will give a very good driving light and provide ignition independently of the battery. The contact breaker unit is very accessible and readily adjustable for variations in ignition timing.
"The front fork is almost identical in design with the bigger Triumph motorcycles, having a very handsome nacelle (which as regards shape is even an improvement) and in which is neatly mounted the switch, speedometer and electric horn.
"The braking is adequate, 5 1/2" by 1" brakes giving a ratio of area to weight in excess of that for a big machine, and also a very long life.
"As regards performance, this cannot be specifically stated other than that the first prototype when assembled exceeded 60 mph and it is hoped that this machine will be able to cruise very happily at 50 mph carrying rider with full equipment."