The Suzuki T20 was the first production six speed motorcycle in the world. It was first manufactured in 1965 ( but introduced as a 1966 model) and was produced until the end of the 1968 model year. It was superseded by an updated version which was designated the T250-1. It was a 247 cc two-stroke twin with many advanced features for the time and its superb performance and reliability helped establish Suzuki's position as a major motorcycle manufacturer.

In the UK the T20 was called the 'Super Six' although in the USA the bike was designated as an X6 with the advertising department tacking on the name of "Hustler".
Advertising brochures produced by Suzuki

Suzuki

is a Japanese multinational corporation headquartered in Hamamatsu, Japan that specializes in manufacturing compact automobiles and 4x4 vehicles, a full range of motorcycles, all-terrain vehicles , outboard marine engines, wheelchairs and a variety of other small internal combustion engines...

 listed the following features to be found on the new model:

• Claimed power of 29 hp
• Claimed weight of 297 lb (135 kg)
• Racing type double leading shoe 8 inch front brake
• Aluminium alloy twin cylinder engine
• Close ratio 6-speed transmission
• Twin 24 mm carburettors
• POSI-FORCE lubrication
• Air pump
• Scientifically designed quiet efficient mufflers
• Safe powerful 8 inch rear brake
• Wide type tail lamp
• Safe bright turn signal lamps
• 3 position adjustable shock absorbers
• Wide, comfortable dual seat
• 3.7 US gal (14 litre) gasoline tank
• Racing type throttle
• Easy-to-read tachometer and speedometer
• Sturdy oil damped telescopic front fork
• 12 volt fully approved lighting system

In comparison to British motorcycles at the time, this was indeed a very high specification, and the T20 model sold in thousands in many countries around the globe.

POSI-FORCE System

The T20 was equipped with a 247 cc two-stroke powerplant, which meant that oil needed to be mixed with gasoline prior to injection into the cylinder. Simple two-stroke designs simply achieved this by requiring the user to combine oil and gas together (a solution known as pre-mix) before filling the fuel tank. However, in an advanced system like the T20, which was expected to operate for longer periods at higher RPMs, this would have been unsuitable. An excess amount of oil would be burned using pre-mix under these conditions, resulting in reduced performance and dirtier emissions, which in turn would cause the exhaust system to become laden with deposits, further reducing performance. The T20 solves this problem by incorporating a once-through oil injection system known as POSI-FORCE, which consists of an engine-driven oil pump coupled to the throttle, which is designed to provide the proper amount of oil needed at the current RPM and throttle opening. The pump draws clean oil from a separate oil tank, and pumps it through hoses into the crankcase, where it is injected into the engine from a nozzle located between the intake manifold and the cylinder. A separate oil injection point is also provided for the main bearing(s) and big end rod bearings of the crankshaft. This dual-point injection made the Posi-Force system far superior to the competitions' single point per cylinder systems. Suzuki would continue to use this system on many of their two-stroke motorcycle designs for many years.

Racing

The T20 immediately had real success on the race course in the 1960s, and many are still used to this day in Classic Racing

Classic Racing

-Definition:The term "Classic Racing" in the United Kingdom is generally accepted as racing as defined under the rules and or auspices of the Classic Racing Motorcycle Club...

 meetings around the world. The T20 has had notable success in the Manx Grand Prix

Manx Grand Prix

The Manx Grand Prix motorcycle races are held on the Isle of Man TT Course every year for a two-week period usually spanning the end of August and early September. The 'MGP' or 'Manx' is considered to be the amateur riders' alternative to the Isle of Man TT Races held in May and June...

 and some riders have managed to lap the famous Isle of Man

Isle of Man

The Isle of Man , otherwise known simply as Mann , is a self-governing British Crown Dependency, located in the Irish Sea between the islands of Great Britain and Ireland, within the British Isles. The head of state is Queen Elizabeth II, who holds the title of Lord of Mann. The Lord of Mann is...

course at over 100 mph on heavily modified T20s.

External links

• Motorcycle Classics article on 1967 Suzuki X-6 Hustler