HONDA The Power of Dreams

In 1964, Honda introduced the Benly CS90, a 90cc class bike with a rear seat. Its horizontal 4-stroke engine borrowed from the Super Cub 90 was mounted on a pressed backbone frame. The CS90 was easy to handle and highly economical with excellent fuel economy, making it popular mainly among young people.

In the late 1960s, however, Japanese manufacturers launched high-output sports models in this class, all powered by 2-stroke engines with a maximum output of 10.5 PS. Honda’s CS90, on the other hand, had a maximum output of 8 PS.

Compared to 4-strokes, 2-stroke engines have fewer parts and are lighter, allowing for a more compact design. They can also produce higher output and are widely used in small-displacement motorcycles. On the other hand, 4-stroke engines, which are Honda’s domain, have more parts, resulting in higher manufacturing costs, but have excellent fuel efficiency due to superior combustion efficiency, and high durability and reliability.

In response to competing manufacturers, Honda newly developed a 4-stroke single-cylinder OHC engine with a 15-degree forward tilt. Its maximum output was 10.5 PS at 10,500 rpm, the same as the 2-stroke engine. Its diamond frame was highly rigid.

The Benly CB90 was the smallest displacement model in the CB series, and its stylish appearance made it an instant hit with young people.

The Benly CB90 was revamped in 1972, with a version equipped with disc brakes added to the lineup. After this model, Honda’s simple single-cylinder road sport model would be succeeded by the CB125JX. Although the Benly CB90 was sold for only a few years, the newly developed engine would be used for a long time as the base engine for 125cc models.