GT380, popularly known as "Sanpachi" [Catalog is a Rearview Mirror of the Times, Part 16]

In 1969, Suzuki released the T350, a road sport model equipped with an air-cooled 2-stroke, 2-cylinder engine and a double-cradle frame.
It was an ambitious product that adopted a 6-speed transmission, which was advanced for its time.

= Eve of the GT380's Birth =

1969 T350

Suzuki's road sport lineup featured a range of distinctive models from 50cc to 500cc.

The T350 was positioned as a large model, second only to Suzuki's largest displacement model, the T500.

1969 Sports Type General Catalog

In 1970, the T350 adopted a slim headlight and a renewed color scheme.

Its pride and joy, the 2-stroke engine, featured an "Alfin cylinder" with a cast iron sleeve, a proprietary Suzuki technology, and was advertised as achieving high RPMs and high output without seizing.

1970 T350

1970 T350

Although it was a road sport model, it featured handlebars with a crossbar. At the time, this was likely adopted for structural integrity.

In 1971, the T350 evolved into the sportier-styled GT350.

The fuel tank shape was redesigned, and its capacity was increased by 3 liters to 15 liters.

The engine's cylinder head fin shape was modified to enhance heat dissipation.

Additionally, the headlight was changed from a slim type to a semi-spherical shape.

"GT" was adopted as Suzuki's road sport brand name, and a series was planned.

1971 GT350 The styling, viewed from below, is impressive

1971 GT350

= The 350cc Class Becomes More Competitive =

1971 Suzuki GT350

1970 Yamaha RX350

1971 Kawasaki 350SS

1971 Honda CB350 Senior

The GT350 had a displacement of 315cc, putting it at a disadvantage in terms of maximum output compared to other vehicles in the full-scale 350cc class.

The Yamaha RX350, also a 2-stroke, 2-cylinder model like the GT350, produced 36 PS, which was 2.5 PS higher.

The Kawasaki 350SS, a 2-stroke, 3-cylinder model, was the most powerful in its class with 43 PS.

The Honda CB350 Senior, a 4-stroke, 2-cylinder model, had a maximum output of 36 PS and appealed with its advanced features, including the adoption of front disc brakes.

Suzuki was compelled to introduce a new model into the fiercely competitive 350cc class.

= Birth of the Classless GT380 =

In early 1972, the long-awaited GT380 was born for Suzuki fans.

It featured a displacement of 380cc (371cc), exceeding the conventional class concept based on displacement.

With a bore and stroke identical to the GT250, it adopted a unique, classless approach by adding a third cylinder to create a 3-cylinder engine.

It is believed to have been influenced by the water-cooled 2-stroke, 3-cylinder GT750, which debuted in 1971.

Furthermore, it adopted Suzuki's proprietary Ram Air System, which increased air velocity to effectively cool the cylinder head.

The 3-cylinder engine with four exhaust mufflers also succeeded in creating a sense of weight and presence.

1972 GT380 The 3-cylinder and Ram Air System convey its power

An illustration of the Ram Air System. Although a simple mechanism, it was innovative at the time and is believed to have contributed to the nickname "Sanpachi."

1972 GT380 Pictured are racing riders Ron Grant (left) and Jody Nicholas (right) as riders

A photo that clearly shows the Ram Air System and the clean exhaust system. Its styling is imposing, surpassing the 350cc class.

April 1972 GT380 Disc Equipped with front disc brakes. Priced at 260,000 yen, 15,000 yen more than the GT380.

= Popularity Surges with the Introduction of the Mid-size License =

Due to the social issue of motorcycle gangs, a new regulation was introduced in September 1975, requiring a large motorcycle license for bikes over 401cc.

Obtaining a large motorcycle license was a difficult challenge with an extremely low pass rate, as there was no formal training system.

Consequently, there was a surge in people obtaining the mid-size license to ride motorcycles under 400cc.

Each motorcycle manufacturer was forced to develop new products in response to the sudden change in licensing regulations.

Honda, whose CB400 Four, released in December 1974, had a displacement of 408cc, had to develop a 398cc model to comply with the mid-size license.

Yamaha and Kawasaki also had to spend extra time and money on these regulatory changes, such as increasing the displacement of their existing 350cc models to 400cc.

The GT380, initially considered to have an awkward displacement, experienced a surge in popularity because it took time for other manufacturers to introduce their 400cc models.

Its body size, which gave an impression of a heavy motorcycle, and its 3-cylinder, 4-muffler setup were favored by fans.

From the 1975 general catalog. The GT380 was priced at 300,000 yen.

Photographed in 2024 at the Suzuki History Museum. This angle truly captures the essence of the "Sanpachi."