The landmark Colleda ST1 is Suzuki’s first fully fledged motorcycle (i.e., a model not powered by a cycle motor) to feature a 2-stroke engine. The Colleda CO that debuted the previous year was Suzuki’s first real motorcycle and was equipped with a 4-stroke engine. The two main engineering policies for the ST1 were to reduce engine noise and develop a durable motorcycle that did not break down. Improvements included preventing slapping noise by adopting an extremely long stroke and reducing the noise from the clutch by using an internal gear for the engagement between the clutch housing and clutch facing. In addition, durability was improved through a careful design process with a zero-tolerance approach to breakage. Durability enhancement measures include the use of four bearings to support the crankshaft and the first adoption of a retainer on the big end bearing of the connecting rod. The engine generates maximum horsepower of 5.5 PS. Sales of the Colleda ST1 exceeded 100,000 units by 1961, and it formed the basis of the subsequent K series of business models.

The Colleda ST3 combines a durable and specially designed channel frame with a 125 cm³ 2-stroke engine that generates maximum horsepower of 7 PS. It satisfies all the requirements of a practical model, including acceleration, hill-climbing performance, and excellent fuel economy of 70 km/L*. Stable riding performance was realized by a low center of gravity and carefully designed handlebar turning and cushioning characteristics. Superb ride comfort was also achieved by adopting hydraulic type telescopic front forks and a sprung rear cushion. Another notable characteristic of the Colleda ST3 is the same horseshoe-shaped headlight as the Colleda TT, which became a feature of Suzuki’s subsequent motorcycles.
* Suzuki’s internal test results. Figures may vary depending on the rider’s skill or riding conditions.

The Colleda ST5 features an improved cylinder that increased its maximum horsepower to 7.5 PS. Its constant mesh foot-operated 3-speed transmission was designed with a gear ratio that matches the engine performance. This transmission realizes smooth shifts in riding conditions from the top speed of 85 km/h to riding over steep hills. A fully enclosed and completely corrosion-resistant chain case was adopted that prevents chain stretching and sprocket wear. The suspension was designed for both ride comfort and carrying cargo by combining hydraulic type telescopic front forks to soften impacts from the road surface with a swing type rear cushion with relatively stiff springs.

The Colleda ST6A features a new and rationally designed air-cooled 1-cylinder engine. This 125 cm³ 2-stroke engine generates maximum horsepower of 8 PS with ample torque from low to high rpms. At the time, this model was well-received thanks to the original Jet Line styling with its flowing arrangement of parts such as the pentagonal fuel tank, tool box, and saddle. It is also equipped with a high-performance electric dynamo that also functions as a starter, adding even greater user friendliness to virtually malfunction-free operation and superb economy. A model was also released that displayed the “S” brand logo on the fuel tank for the first time.

The Colleda 125SH mounts a practical type 2-stroke air-cooled 1-cylinder engine that emphasizes performance at low rpms on the same frame as the Colleda Sel Twin SB. This gutsy long-stroke engine also delivers excellent fuel economy of 70 km/L (40 km/h steady state fuel economy*). Other notable features of this model include covered telescopic front forks, a starter mechanism equipped with a powerful dynamo, and a 35-watt sealed beam headlight. The Colleda 125SH also features Suzuki’s aggressive-looking Jet Line styling.
* Suzuki’s internal test results. Figures may vary depending on the rider’s skill or riding conditions.

The Colleda 125SL mounts a 125 cm³ 2-stroke 1-cylinder engine on the same chassis adopted by the 2-cylinder 125SK. This gutsy and well-received long-stroke engine generates excellent torque at low rpms while delivering maximum torque of 10.8 N·m at 4,000 rpm. This is a tough and practical model that features a rotary 4-speed transmission, and realizes powerful hill climbing performance and excellent steady-speed fuel economy of 70 km/L*.
* Suzuki’s internal test results. Figures may vary depending on the rider’s skill or riding conditions.