THE YAMAHA RD STORY
How it all began …
By one of the members.
Although the Japanese big four, Honda, Kawasaki, Suzuki and Yamaha, today imply that they are centuries old, is actually quite different.
In the motor industry, these four youngsters simply and it is therefore all the more remarkable that one has been able to indulge in, say, to develop purebred copycats to leading engine builders four decades
The names of the four are admittedly more than a hundred years associated with technology, but mainly in the ‘Heavy Industries’, ranging from organ to bridges and aircraft.
The post-war industrial development in the east appeared suddenly a huge market for motorized two-wheelers. Only then came the big four as engine builders in the picture.
Soichiro Honda produced its first “motorized bicycle” in 1946 and the first full own product, the Cub, was born in 1951 and that was a glorified Spartamet.
Although the product name Kawasaki dates from the late 19th century, but the first real Kawasaki motorcycle was shown to the press in 1962 and came directly from the acquired by Kawasaki Heavy Industries Meguro motorcycles factory.
The same fate was granted only young born Suzuki. This company began by overcapacity of production in 1952 until the construction of motorcycles.
And what about the Yamaha?
YAMAHA, … MORE OF THE SAME
Torakusu Yamaha began in 1887 with the production of organs and quickly grew the company into a healthy company called Nippon Gakki Co.. Ltd. The company was the largest manufacturer of musical instruments and aircraft during the war were made. In 1954 started the production of engines and the Yamaha name, named after the founder, was born.
To jump ad-hoc in the demands of the market and to ensure that one would miss the stormy development management the same as all the other Japanese two-wheeler companies in that period did did. Replicating!
The philosophy of the Japanese at that time was clear and left nothing to the imagination: ‘copied more good than bad invented “was the creed and shamelessly English and German products were counterfeit.
Thus began the history of modern Yamaha.
The first Yamaha motorcycle rolled off the band in 1955 and was named YA1 and nicknamed “Red Dragon” because of .. correct.
The bike was meticulously copied from the German DKW RT125 showstopper. No shame because another European brand, BSA Bantam would release, which was also a copy of the RT.
A year later they later did that trick again with a copy of the RT 175.
Anyway, the base was the single cylinder 125cc two-stroke and put this philosophy would have followed a year later with the construction of a two-cylinder that would become the basis of the famous series of two-strokes, which you, dear reader, so appreciates.
THE FIRST 250 cc TWIN
The example of the first twin Yamaha would be the German Adler. The MB250 was a good but expensive two-cylinder, whose production in Germany was undermined by the high cost.
The frame of the new twin was developed by Yamaha in-house and in 1956 the 250 was shown to the public under the name “YD 1 ‘and this bike would see a development that are unparalleled would not know. Stroke in the world
Characteristic of this air-cooled engine was the secondary chain drive was mounted on the left crank pin, just as was the case at the Adler. On the right side and the clutch Also, were the carters to good old custom, split vertically.
This impossible coupling structure would otherwise sustain nearly 10 years in unchanged form, although it is often a source of distress appeared. The breathing of the two cylinders was still done by only one carburetor.
But otherwise was YD1 a fairly modern motorcycle, stripped by the Yamaha technicians so detested rocker arm front suspension and plunjervering at the back, as it was developed. By Adler Thus, given the YD1 really is a sound of their own work.
Besides the YD series soon, races in Japan (a kind of glorified hill climbing) was under the influence of the famous Asama S series under the name YDS1, which in turn would form the TD 1C racer the base. You still with me?
However, outside of Japan had noticed no one of these skirmishes because the engines were not yet exported.
That took place around the sixties when the successor to the YD1 the yd2, was released and it was going to be. Sold outside the country’s borders For example, in 1960 the evil outside world for the first time with the 250cc two-stroke Yamaha twin yd2, then a discreet and moderate newcomer.
YDS 3: A quantum leap
The Japanese learned quickly and after the introduction of the export unexciting yd2 was released in 1964 YDS3. In this model, many shortcomings of the previous models were improved. There were now serious brakes on board, the cast iron cylinders were each carburetor and the tubular frame was improved and derived directly from the racing version.
Still had no real frame cradle shape and striking the construction was the lack of parallel standing cradle tubes behind the block upwards.
The coupling structure remained unchanged as well as vertically split crankcases.
Besides these YDS3 a 305cc version was also released, the YM and also found the ‘Tour’ version of the YD3 the way to the consumer. The YDS3 was a reasonable sales success and hitchhiked a bit along with the successes of Honda. Particularly in England sold the 3 well. In the Netherlands, there are still a handful anno 2002 YDS 3 copies left.
The YDS 3 was actually the last copy that was still completely built according to the old Adler concept.
Because number 4 is an unlucky number in Japan, in 1966, the successor to the YDS3, the DS5 launched and this machine had one motor changed dramatically.
The clutch finally disappeared from the crankshaft and got a place on the primary gearbox shaft, cast iron cylinders were replaced by aluminum ones and DS5 had novelty as an electric starter, which unfortunately could ensue. Again a source of misery.
The last gasp of the DS6 YD1 offspring would be and that was the concept milked to the last bolt crankcase.
Fortunately, the Japanese saw themselves and do not commit the mistake that the British motor industry in the same period made by endlessly embroidering on a concept and itself marked the end of a successful motor industry.
Parallel to the DS6 was also a new (for the time) heavy twin presented to the public in 1967, the R1. Initially it was a bit skeptical about this bike because it was thought that the thermal problems such heavy air-cooled two-stroke entailed, it was not the boss. But that turned out to be huge.
The R1 (or YR1), was a completely new engine with horizontally split crankcases, crankshaft with a labyrinth seal, aluminum cylinders, the chain drive links and a bore and stroke dimensions of 59.6 x 61 mm.
The expert sees these values immediately that the crankshaft is not the same as the later 250/350 series. The true freak could immediately know what we mean by the statement 54.54 (Yamaha would in all 250/350 racing and touring use two strokes later years crankshafts with a stroke of 54 mm. With a 250cc was also taking the bore 54 mm).
As successor in 1968 the concept car, the R2 released, but it was never officially sold in the Netherlands, to my knowledge.
Personally I find the YR2 the finest two-stroke Yamaha that has ever made. Typical were the straight exhaust and headlight with integrated tachometer and speedometer.
But this machine was soon ousted and succeeded in Netherlands by YR3. This was the last major stroke in the old jacket. Admittedly, the cylinders now five gates and had taken the necessary steps to appearance as two separate counters and so-called trumpet outlets, but there was a new 350 to knock on the door and it would become one of the most popular two strokes ever: the R5 .
The 250cc DS6 concept was in those years also thrown overboard, and the successor of the DS7. Most well known for the beautiful golden layout.
This bike was like the R1, horizontally split crankcases and aluminum cylinders. The DS7 had by now a 54mm crankshaft and was a truly amazing good bike and the exponent of all the knowledge that Yamaha had in the house in two strokes.
The engine was so down and in the years that followed only attention was paid to increasing the performance.
So now there were two successful and well-strokes 250cc and 350cc R5 DS7.
In fact, there are only two major surgeries followed in both bikes. Early 70s were both models Reed Valves built into the intake system and the names of the bikes were customized with the designation “RD”.
The last major change took place in 1978 when the 350 cc water cooling was applied and RD LC had evolved into a full-fledged, fast and reliable stroke.
But this story was not finished. The two-stroke Yamaha continued for a large group of fans and selected a popular bike and it would continue to develop the two cylinders, so the RD would go. In a third youth for years.
Thanks to Adler.