and now I will be presenting the story behind yamaha spark 135 or Yamaha jupiter MX 135 LC (old edition), its comment from chassis, engine and exterior design
check it out
Mr. Kiyotaka Uemura (exterior design)
One of the biggest deciding factors in whether or not a machine is really one that you want for your own is the exterior design. Mr. Kiyotaka Uemura of GK Dynamics who was in charge of exterior design says, “Basically, I went after the design that looked coolest to me.” He goes on to say, “I would say in more specific terms that it is a sporty design with an aggressive look. I tried some innovative things while also staying within the bounds of what a moped is. I wanted to express the excitement and tension of pushing it to the very edge of that definition.
Project Leader Kuromoto says with a laugh, Kiyo-san [Uemura] can be a stubborn man, once he decides a design is good it is hard to change his mind. Then he adds: “But that is probably what makes a professional designer. Kiyo-san had digested a lot of information about the preferences in the countries the T135 was being designed for, and after that he followed his own designer instincts. In the end, a good design is a universal thing that transcends national borders.”
“It’s not like I won’t change anything no matter what. And the purpose is not to push my original design through, no matter what,” says Uemura with a smile. “There are times when we have to change the design for functional reasons. But working on this project was especially easy because when I’d sit down to talk things out with the engineers we found we were all working in basically the same direction.”
We often hear of function and design spoken of as conflicting factors in motorcycle design, but Uemura insists that is not necessarily the case. “In places where function takes precedence, it can still be an appealing element if it is well designed,” says Uemura. “I believe that if you are really attentive to the overall design and all the details, the design as a whole and the things I want to say through it will not be compromised if function is allowed to take priority over design in a few places.”
Mr. Toshimasa Miyabe (chassis design)
Traditionally, what we call “Yamaha Handling” is outstanding handling stability that makes it easy for anyone to enjoy riding with full assurance and also, the kind of handling that responds faithfully to the will of the rider. And, of course the T135 is part of this tradition. So the T135 had a lot to live up to in the area of chassis design and lot of effort went into building a chassis for this model that met Yamaha’s high standards. The adoption of liquid cooling meant that the layout had to accommodate resulting components like the radiator, and this was a first for a Yamaha moped. What’s more, it had to be done without compromising the “Yamaha Handling.” That set the bar very high for Mr. Toshimasa Miyabe, chassis design project chief working on the T135.
“In order to build a frame that gets a high level of rigidity while accommodating all the various functions a frame must, the easiest thing is to make it broad-boned and rugged,” says Mr. Miyabe. “But, if you are a Yamaha frame designer, you want to build the lightest, slimmest frame you can. Personally, I have a very strong inclination to make everything as light as possible.”A light frame is one of the essential elements of a light-handling machine. That’s why the passion for lightness is in the blood of every Yamaha engineer.
It was on the T135 project that Mr. Miyabe was given the position of Project Chief for the first time. There were a lot of important decisions for him to make, like the engine position and the shape of the frame. And there were some high hurdles to clear in areas like frame weight and production cost. There was also the tough final hurdle to be cleared on the test track. Things that seemed to work well in computer simulations were shot down by Kamimura and his test riders. In the early stages of the project that was especially true.
“Sometimes the demands from the test team seemed almost impossible to satisfy,” recalls Miyabe. “But we never wanted to say something couldn’t be done. It is tough demands that ignite the passion of a design engineer: to tackle problems that at first seem impossible.”
Mr. Tatsuya Masuda (engine design)
The power unit mounted on the T135 is a completely new liquid-cooled 4-stroke 135cc single-cylinder engine. It is the first liquid-cooled engine ever mounted on a Yamaha moped. Tatsuya Masuda, who headed the engine design project team says, “We wanted an engine that would run strongly at high rpm in the countryside and be easy to use in slower mid- to low-speed range riding in the city.” He goes on to say, “We also wanted it to be an engine that ran quietly and was very reliable. And to do this we spent an especially large amount of time and energy working out that most important spec for determining the character of an engine: its bore x stroke.” The T135 adopts a liquid cooling system and an array of state-of-the-art technologies like Yamaha’s DiASil cylinder and forged piston. But it was this bore x stroke that consumed much of Masuda’s efforts. It was with this spec that he sought to give the engine a truly Yamaha character.
“If you get this basic spec right, you can do a lot of things later to fine-tune the engine,” says Mr. Masuda. It was around October of last year after a series of road tests in Thailand that Masuda was finally convinced they had the right bore x stroke spec. Project Leader Kuromoto looks back on that time: “When I saw Masuda in the hotel lobby after those test were over, there were tears in his eyes. He had gone to Thailand with the motorcycle himself to see how close it was to the image he had been working toward and I guess he was really pleased. That’s how difficult the task he had been given with the T135 engine was: to get both low- to mid-speed ease of use and good power at high speeds.”
“I was confident that I had chosen the right spec,” says Masuda, “but I guess I still had some doubts going into the tests, and it wasn’t until the results were in that I was 100% sure we had the right basic engine to build on. ”Laughing, he went on to say, “It was such a relief that I just couldn’t hold back the tears. Crying like that was something I didn’t even do when my first child was born.”
reference from : yamaha japan