250cc Single Cylinder, 2 Stroke
|Bore / Stroke||53.3mm x 53.3mm|
|Horsepower||15.02 HP (11.2 KW) @ 6000RPM|
|Torque||14.01 ft/lbs (19.0 Nm) @ 4000RPM|
|Transmission||Gear box: 4-Speed
Final Drive: Chain
|Suspension||Front: Telescopic forks
Rear: Swing arm
|Length||76.18 inches (1935 mm)|
|Width||27.8 inches (706 mm)|
|Weight||140.0 kg (wet)|
|Recommended Oil||Yamalube 10w-40|
Yamaha, the youngest of the "Big Four" Japanese motorcycle manufacturers, didn't build its first two-wheeler until 1954, when it unveiled a copy of the DKW RT125, calling it the YA-1. This spidery motorcycle was a great success. It won handily the first cindertrack hillclimb ever held at Mount Asama, north of Tokyo, in both 125 and 250cc classes. It was a decisive moment for Yamaha.
Inspired by Adler
But Yamaha's competitors were not standing still, so in 1957 Yamaha launched a new 250cc model, this time based on the Adler MB250. The new bike's main difference was in its frame, which was a pressed steel copy of the German Adler's cradle frame. Maybe that wasn't such a good idea! The first racing versions of the 250 YD1, seen at Mount Asarna in 1957 and in the Catalina United States Grand Prix in 1958, went back to the original German cradle design.
A Brilliant Dynasty
This is a model born out of a pursuit of design originality. In the development as well, the design elements proceeded the engineering. Taking as its key words “A 250cc for the Japanese,” it was given a compact and easy to ride body size that fit the Japanese physique. What’s more, it embodied a “Dynamic design” that gave the impression of powerful dynamism in any situation. It also mounted Yamaha’s first 2-cylinder engine. In a Japanese market dominated at the time by utility models, the YD-1 brought a new image of sports performance.
Yamaha was a fast learner and, within a few years, its twin had cast off all traces of its origins and had given rise to a motorcycle dynasty. The first was the electric-start YD2. Then came the first dedicated sports models, the YDS1 and the YDS2 (the first model exported to Europe). Yamaha competed in its first French GP at Clermont-Ferrand in 1961 and returned in 1965 with a succession of famous riders -Vesco, Read, Redman, Ivy, Saarinen, and Agostini.
First US model
The first known Yamaha motorcycle in the US was purchased in Japan by Sgt. First Class Charles Butler of the US Army and brought to this country after his tour of duty in October 1957.
The bike has a 4-Speed transmission. Power was moderated via the Wet multi-disc clutch.
It came with a 2.50-16 front tire and a 2.50-16 rear tire. Stopping was achieved via Drum in the front and a Drum in the rear. The front suspension was a Telescopic forks while the rear was equipped with a Swing arm.
1957 - 1959 Yamaha YD-1
This is a model born out of a pursuit of design originality. Taking a 250cc for the Japanese as its key words, it was given a compact and easy to ride body size that fit the Japanese physique. It also embodied a dynamic design that gave the impression of powerful dynamism in any situation.
- Yamaha YD-2 upgraded the YD-1 in 1958 by introducing electric start.