Vol.01 YZF-R7
CHALLENGERS OF
MONOZUKURI
Story of New Model Development
CHALLENGERS OF
MONOZUKURI
Story of New Model Development
Vol.01 YZF-R7
CONTINUOUS SMALL EFFORTS CREATE MAXIMUM VALUE
Under the concept of “Fun master of supersports,” the YZF-R7 has recently appeared on the Japanese domestic market. We interviewed the development team of this motorcycle, who produced the latest model of the R series supersports based on the sports naked motorcycle MT-07.
STRATEGIC MODEL DEVELOPED IN A CONTRARIAN APPROACH; CONVERTING A SPORTS NAKED MOTORCYCLE TO A SUPERSPORTS MODEL
A new motorcycle has been launched using an approach that is rarely seen in recent years. It’s a new middle-class supersports motorcycle, the YZF-R7 (hereinafter referred to as the R7). In many cases, sports naked motorcycles are converted from supersports (hereinafter referred to as SS) models, but this time the opposite approach was taken. To develop the R7 as an SS motorcycle equipped with the form and high sports performance of the R series, the main components, such as the 689cc in-line 2-cylinder water-cooled engine and frame, were diverted from the MT-07. To expand the market of this strategic model globally, the manufacturer’s list price in the Japanese domestic market is set for ¥999,900 (tax included).
We interviewed the five members of the development team: IMAMURA Mitsutoshi, who was assigned to YMDA after serving as the project leader; HASUMI Yousuke, the project chief of the vehicle testing; WAKIMOTO Yojiro, the body designing project chief; SETOU Hiroomi, who was in charge of riding tests and evaluations; and UEDA Daisuke, who was in charge of the exterior designing.
FOR THE NEW APPEAL OF THE R SERIES “THE FUN MASTER OF SUPERSPORTS ” ANYONE CAN RIDE WITH EASE
“The target we aimed at for the R7 was an SS right in the middle of ‘cool’ and ‘comfortable,’ ” says Imamura. In other words, it’s an SS not too much for circuit use, but for fun riding on public roads. “Comfortable motorcycles can be ridden by anyone with ease. In addition to comfort, we wanted to develop a motorcycle that makes the owner want to run on the circuit with the R1 or R6 in the future,” adds Imamura. The concept of the R7, “Fun master of supersports,” was born of such an idea.
Behind the development was the trend in the US motorcycle market, where the 600cc-class SS was popular. But brand-new motorcycles were too expensive to buy, so the secondhand market was booming. In addition, as conversion of a naked motorcycle to a full-fairing type was popular, people were looking for affordable SS motorcycles.
Under such circumstances, YMUS already had built a prototype in 2017 using the MT-07 with inverted front forks. There was actually a prototype that would serve as a foothold for the R7 development. “That prototype was sent to us along with local information. It was fun to ride and I thought it would become a marketable product,” says Hasumi. The development team was set up immediately in the following year. Imamura says, “Since we already had the prototype, it was quite easy to draw up a plan.” However, the development path was never that easy.
PF Model Development Section, PF Model Unit
EVEN THE SLIGHTEST MISSTEP WOULD HAVE INEVITABLY LEFT EVERYTHING UNFINISHED WHAT IT SHOULD BE WAS SOUGHT THROUGH A REPETITION OF TRIAL AND ERROR
When you look at the highlights in the catalog, you can find that many attractive features were adopted for this motorcycle that contribute to steering stability and controllability, such as inverted front forks, center brace (reinforcing material), assist & slipper clutch, and Brembo-made radial pump brake master cylinder, as well as the R7’s sharp and combative looks.
To realize them, however, there were a number of major hurdles to overcome, one of which was the frame. The adoption of the inverted front forks was a must-have requirement to improve riding performance and make the motorcycle more attractive. But due to their high rigidity, just installing inverted front forks did not balance with the frame. Furthermore, “It was very difficult to find proper goals and points that we thought were the best,” Imamura recalls. In other words, they had difficulty in expressing “just right” concretely. Although the direction was clear, even the slightest misstep would have inevitably left everything unfinished. For example, it was difficult to quantify the transient characteristics while leaning on a motorcycle. These characteristics all relied on the test rider’s feeling. The R7 should not be a type of motorcycle that competes for speed and time, but it needed SS-like riding feeling and steering stability. The development team worked together to seek an ideal clear target of how and at what level the R7 should be developed.
PF Model Development Section, PF Model Unit
One example is the center brace for complementing rigidity. “Time was limited. We couldn’t wait for the output from the designing and engineering members. So we did test-riding and analyses in parallel,” says Hasumi. At the testing site, they test-rode and made changes over again and again. “I tried as much as I could think of, such as welding iron and aluminum pipes. Even if I thought some idea might work well, I had to consider the cost and fairing mounting. At one point when I tried replacing the original plastic pivot cover with a metal plate using a rigid-mount method, I felt the riding quality improve and thought this was what I wanted,” says Setou. Immediately after the designing members heard how he felt, they took action. “Based on Setou’s opinion, I designed the center brace that also served as an exterior part using aluminum die-cast material. After that, I redesigned it through a repetition of trial and error,” says Wakimoto. As a result, the rigidity was enhanced by about 20% compared to the MT-07.
The frame had an additional modification. As Setou didn’t want the R7 to be a typical SS motorcycle, he pursued easy handling by taking advantage of the MT-07’s smooth characteristics. In response to Setou’s request, Wakimoto also sought an ideal image of the R7 by making fine adjustments, such as adjusting the rigidity of the crown handle and the under bracket.
PF Model Development Section, PF Model Unit
THE DESIGN AND FUNCTION THOROUGHLY REVIEWED, BUT COOLNESS AND EASY HANDLING WELL BALANCED
The exterior including each fairing was also a big challenge. The concept of the development team and designing team was “skinny figure”. Therefore, they paid meticulous attention to the fineness. Under Imamura’s philosophy, “Functionality should be pursued especially for compact motorcycles and the functionality should be compact,” ideas of the development team were reflected in the functionality as well as the exterior.
The major challenges they faced with the exterior were bank angles and airflow. An example of these is the R7’s symbolic aluminum under cowl. Normally it’s made of plastic, but the R7’s is aluminum. The reason is “In the first place, the MT-07’s engine is not designed to have fairings and it has a large oil pan at the bottom. If the under cowl is made of plastic, it is necessary to take a large distance from the heat source, but by doing so, it cannot secure sufficient bank angles, so it won’t be attached in a normal way. Thus, we decided to adopt the aluminum under cowl,” says Imamura.
However, aluminum parts always come with problems of cost and production method. Imamura rushed to in-house press welding engineers who worked on aluminum parts in the R1 and XSR projects, and eventually obtained the understanding and cooperation of the manufacturing members. With this under cowl, the R7 was able to have a maximum bank angle of 53 degrees.
Other than this, a considerable number of trial and error tests were done with the exterior from the front cowl to the tail area in terms of visual appearance and functionality. Converting a naked motorcycle to a full fairing type involves thermal problems. It is necessary to secure fresh air not only for cooling the engine, but also for keeping intake air from rising due to the heat trapped.
Therefore, the front cowl, for example, suppresses the rise in intake air temperature by adjusting the shape of the M-shaped duct, in which the headlights are embedded, and installing an air introduction port under the position light to create an air guiding path down to the air cleaner.
In addition, a rectifying plate was installed in front of the tank cover so that the air taken would not disperse and escape in the path. Although not visible externally, these are the parts that the development members paid particular attention to through repeated wind tunnel experiments.
PF Model Development Section, PF Model Unit
SOMETIMES YOU CAN FORGET ABOUT RESTRICTIONS AND FOCUS ON MANUFACTURING FROM RIDERS’ PERSPECTIVE
Another part of the R7 that should be noted is the fuel tank. They repeated redesigning it an unprecedented number of times. “I redesigned the tank over and over again even after the clay check was finished. Normally, the engineering members don’t reduce anything, but I was so carried away with optimizing the tank that the designing members pointed out that I was trying to remove a critical area that should not be reduced,” says Ueda. It was Setou who mainly placed orders always considering controllability and easy handling of the motorcycle from customers’ perspective. As a result, not only does the tank have a unique shape, but also it contributes to lowering the seat height and offering sufficient space for operation.
PF Model Development Section, PF Model Unit
This symbolizes the excellent cooperation between the engineering and designing members who accepted Setou’s accurate ideas and turned them into shape.
“I think we had many conflicts of opinion with the designers. But because we mutually made efforts to understand and share the goals and ideals of the R7, we were finally able to create an ideal form of the R7,” says Imamura. He also says that the designers helped him a lot, especially about the area around the tail. Due to its almost flat shape, the seat rail of the MT-07 is not suitable for modeling the tail into a rising tapering-off shape, which is typically seen in SS motorcycles. But the designing team’s ingenuity has realized a flowing shape that makes you feel the DNA of the R series.
PF Model Development Section, PF Model Unit
PF Model Development Section, PF Model Unit
ADDING NEW VALUE TO EXISTING THINGS BY PAYING EXTRA ATTENTION TO SMALL DIFFERENCES REPEATEDLY
Furthermore, to improve controllability and operability, the optimal seat height was set by the millimeter, the heel plates were modified for better fitting, and the shift feeling was also improved. They did so many small adjustments and brought so many parts from other models that all of those cannot be introduced here. “It’s not too much to say that nothing but the frame and engine is the same as the MT-07. I thought it would be possible to share more parts, but actually it wasn’t,” says Imamura. By aligning the vector for each part, the R7 was finally born.
Through the interview, you can get a glimpse of how the team members faced the same direction and communicated properly to proceed with the development. You can also feel that they had solid understanding and sharing among the members while repeating trials and errors, and they had a clear picture of what they should be heading for.
“We shared even the smallest things and communicated with one another so that the project wouldn’t move forward without some members’ knowing,” says Imamura. Hasumi also says, “I made frequent trips to various places and tried to have face-to-face conversations with the persons in charge.” You can see that they went out of their way to other departments, promoted mutual understanding and shared information.
There is a saying “God is in the details.” The R7 is a motorcycle for which the development members’ uncompromising attitude crystallized. If you look at the high evaluation by the media, it’s no exaggeration to say that the perfection of the R7 has such high value that no one can say it’s a diverted model.
The R7 may have the potential to create an SS motorcycle of a new era or perhaps a new category.