Editing Yamaha YD-1

{{Infobox Motorcycle
|name             = '''Yamaha YD-1'''
|image            = [[Image:Yamaha-YD1.jpg|frameless|thumb|Yamaha YD1]]
|aka              = 
|manufacturer     = [[Yamaha]]
|parent_company   =
|production       = 1957
|model_year       =
|predecessor      =
|successor        =
|class            = [[Naked]]
|engine           = 250cc Single Cylinder, 2 Stroke
|bore_stroke      = 53.3mm x 53.3mm
|compression      =
|top_speed        =
|power            = 15.02 HP (11.2 KW) @ 6000RPM
|torque           = 14.01 ft/lbs (19.0 Nm) @ 4000RPM
|ignition         =
|spark_plug       =
|battery          =
|transmission     = Gear box: 4-Speed <br>
Final Drive: Chain <br>
Clutch: Wet multi-discs <br>

|frame            =
|suspension       =Front: Telescopic forks <br>
Rear: Swing arm
|brakes           =Front: Drum <br>Rear: Drum
|front_tire       = {{tire|2.50-16}} 
|rear_tire   	  = {{tire|2.50-16}} 
|rake_trail       =
|wheelbase        =
|length           = 76.18 inches (1935 mm)
|width            = 27.8 inches (706 mm)
|height           =
|seat_height      =
|dry_weight       =
|wet_weight       = 140.0 kg
|fuel_capacity    =
|oil_capacity     =
|fuel_consumption =
|turning_radius   =
|related          = [[Yamaha YD-2]]
|competition      =
}}

The '''[[Yamaha]] YD-1''' was a Single Cylinder, 2 Stroke Naked [[motorcycle]] produced by [[Yamaha]] in 1957. Max [[torque]] was 14.01 ft/lbs (19.0 Nm) @ 4000 RPM. Claimed [[horsepower]] was 15.02 HP (11.2 KW) @ 6000 RPM.  

==History==

[[Yamaha]], the youngest of the "[[Big Four]]" [[:Category:Japanese motorcycles|Japanese motorcycle manufacturers]], didn't build its first two-wheeler until 1954, when it unveiled a copy of the [[DKW]] [[DKW RT125|RT125]],calling it the [[Yamaha YA-1|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==
[[Image:1957 Yamaha YD-1.jpg|200px|thumb|left|1957 Yamaha YD-1]]
But Yamaha's competitors were not standing still, so in 1957 Yamaha launched a new 250cc model, this time based on the [[Adler]] [[Adler MB250|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 [[Yamaha YD2|YD2]]. Then came the first dedicated sports models, the [[Yamaha YDS1|YDS1]] and the [[Yamaha YDS2|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==
[[Image:1967 Yamaha YD-1.jpg|200px|thumb|right|1967 Yamaha YD-1]]
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.



==Engine==
A 53.3mm [[bore]] x 53.3mm [[stroke]] result in a [[displacement]] of just 247.0 cubic centimeters.  

==Drive==
The bike has a 4-Speed transmission. Power was moderated via the Wet multi-discs.  

==Chassis==
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==
[[File:yamaha-yd-1-1957-1959-3.jpg|600px|1957 - 1959 Yamaha YD-1]]
[[File:yamaha-yd-1-1957-1959-2.jpg|600px|1957 - 1959 Yamaha YD-1]]
[[File:yamaha-yd-1-1957-1959-1.jpg|600px|1957 - 1959 Yamaha YD-1]]
[[File:yamaha-yd-1-1957-1959-0.jpg|600px|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.

==See Also==
*[[Yamaha YD-2]] upgraded the YD-1 in 1958 by introducing electric start.
{{Yamaha}}

[[Category:Yamaha motorcycles|YD1]]
[[Category:Naked motorcycles]]
[[Category:1950s motorcycles]]