Everyone knows that the very recent Yamaha R7 is derived from the MT-07 from which it almost entirely incorporates the 689cc twin-cylinder crossplane engine set at 270° which delivers 73,4 horsepower at 8750 rpm. However, it is not enough to put a fairing and bracelets on a roadster to make it a sports car, far from it.
It is therefore the fruit of a long meticulous work that the brand with three tuning forks offers to its customers, except that, until now, it was generally necessary to be content to visually play the game of 7 differences, the documentation on the subject being almost non-existent.
Although, with the exception of the FCC clutch, the engines are the same between the two models, the frames differ slightly in their use. First of all, if the caster remains at 90mm on the two motorcycles, the caster angle goes from 24º50 to 23°40 on the R7, in order to make it more manageable. But that's about the only technical feature regarding geometry available on the official website.
Fortunately there is Takuma Aoki ! For the youngest, it is the paraplegic Japanese driver who took part last year in the 89th edition of the 24 Hours of Le Mans at the wheel of the Oreca 07-Gibson #84 of Association SRT41 entered in the Innovative Car category by Frédéric Sausset. Those “a little less young” will not have forgotten that he is the youngest of three brothers (with the eldest Nobuatsu and the youngest Haruchika) having participated in the motorcycle Grands Prix in the 90s before suffering his terrible accident during testing with his Honda 500cc on the Tochigi circuit in Japan, in early February 1998. Paralyzed in both legs, he has nevertheless remained in the Honda fold ever since and has taken on numerous challenges, notably by participating in the Dakar rally.
But when he doesn't give us a real life lesson by driving a car, or even a motorcycle, Takuma Aoki turns into a journalist, and that's what interests us today since the man went to a rather technical presentation of the Yamaha R7 on the Sodegaura Forest Raceway circuit, not far from Tokyo Bay.
By viewing his video, and even without speaking Japanese, we discover some interesting elements distributed by Yamaha, starting with the side drawings which clearly illustrate the common genes of the two machines.
What follows is a focus on the triple clamps, which is important. In addition to the center distance of the fork tubes increasing from 190 to 210mm, the offset is reduced from 40 to 35mm, resulting in a new and reversed distribution of masses: rear centering at 50,6% for the MT-07 , on the front at 50,7% for the R7. As a result, the wheelbase is also reduced by 5 mm, to 1395mm. Pilots will appreciate…
In passing, it should be noted that the caster angle figures differ very slightly from those indicated on the official website, but this does not matter since the difference remains the same.
At the rear, the KYB spring/shock absorber combination has its setting tightened from 120 to 135N while the link rod is reduced by 4 mm to raise the rear of the motorcycle.
Partly for this (but not only), the saddle height increases from 805 to 835mm. Indeed, the geometry of the rider has been completely revised, with also a raising and advancement of the footrests of 60 and 52 mm respectively, as well as a lowering and advancement of the handlebars of 174 and 152 mm respectively.
In total, we therefore find ourselves with a position very close to that of the R1 and the R6…
All this also has an influence on the maximum inclination angle which goes from 49° on the MT-07 to 53° on the R7, very far from the 57° of the R6…
But it is not enough to adopt a pilot's position on a motorcycle with reinforced suspensions and brakes to make it a sporty one, so Yamaha has also increased the rigidity of its chassis part. First of all, by optimizing the lower triple clamp thanks to a CAD study and production in forged aluminum…
… then by the addition of a central aluminum reinforcement rigidly mounted on the steel frame, the whole providing a gain of 20% in torsional rigidity around the swingarm pivot.
Obviously, the front axle has also been revised, with the adoption of an adjustable KYB inverted fork with a diameter of 41mm, braking including the radial calipers of the R1/R6 and a Brembo radial master cylinder, as well as Bridgestone Battlax tires Hypersport S22.
The FCC anti-dribble clutch already mentioned is called Assist & Slippers. It removes the influence of rear torque, such as when downshifting, on vehicle behavior, removes excessive engine braking and improves the feeling of stability during deceleration. In addition, the operating load of the clutch lever has been reduced by approximately 33%. The system is however not new, present for example on the XSR900 since 2016.
Here he is at rest:
When accelerating, the system tends to compress the discs…
…and does the opposite when decelerating.
The list of modifications does not stop there, for example with the reduction of the master torque, the adoption of the Quick Shifter or the secondary ratio of the R7 changed from 43/16 = 2.678 on the MT-07 to 42/ 16 = 2.625 on the R7, but we can already see that Yamaha's new concept is in fact anything but an MT-07 dressed like a sports car...
