MARUMASU Motorcycle Lounge

2006 - 2023 Specializes in Harley-Davidson / Japanese Classics Maintenance & Speed Pro Shop " The Spirit of Bonneville Salt Flats" Land Speed Racing. / 2010/2011 FIM World Speed Record : 2011/2014 AMA National Champion : 2017 Fastest EV Motorcycle in Colorado Mile Race.



Self-consideration in High_speed crashed. (English Ver.)

would like to keep in mind what I am thinking about this time about why the fall was caused this time as a memorandum.

R0242196 のコピー

"EV - 02" of Mobitec who developed from zero at a fast pace of about 9 months for the race this time this time.
We conducted a verification at Chassis Dynamo in May and conducted a shakedown at the Shirosato Test Course on June 14-15.
Shirosato was short distance 1.6 km from the straight test course, and on the second day we had strong rain on the 5.5 km long oval course, the maximum test speed in Japan was about 200 km / h.
However, considering the basic design, strength analysis is also the best part of Mobitec's, even considering the analysis result at the wind tunnel experiment facility, it is thought that there will be no problem at higher speeds, then I came to Bonneville this time.

The course condition was quite good as I heard this time.
In the domestic test we were restricting the battery power, but in the actual race we ran with full power using 100%.

The first one started carefully to check the condition of the course and the bike body, but after the start the main power supply went down and stuck on the course as it was. Although I was experiencing twice in domestic tests, I was able to reboot without any errors, in particular, so this time it is recovered as well this time. There is no problem on the data.

For the second time to follow, I could start without problems and accelerated with the feeling of opening a certain amount of throttle and holding. The GPS meter showed about 270 km/h before the measurement section, but later the side swayed slowly from the front around it.
The tremors are soft, I judge it to be a phenomenon that occurs when the suspension preload is weak. Since I was able to control the motorcycle, I dropped the vehicle speed to 220 km/h and accelerated toward the exit of the measurement section. But since the shake started again at around 250 km/h, I used the front brake to slow down and finish the line. Because the average speed was 150 mph, it is not so fast for EV - 02.

I returned the situation to the pit and changed the setting of the front suspension. In brief, the setting was adjusted to harden.This time EV - 02 is a vehicle with front and rear suspension, but rear does not change so much.

Three times when I changed the setting of the suspension, a sideways shake took place again, but I discovered that when using the rear brake the shake would decrease. (Currently, because of the depth of the bank angle in MOTO - GP etc., the rear brake is not equipped with a foot brake, but "Thumb bar" which is controlled by the thumb on the left handlebar is attached.) I released the rear brake when the shaking decreased, and continued using the rear brake when the shaking began, finishing the course. The speed is still around 150 mph.

Generally, when rolling starts from the front, I think whether the setting of the front suspension is sweet or the strength shortage around the frame neck is considered. However, this time, it seems that the balance relationship with the rear shock is misdirected by strengthening the front suspension, and shaking has occurred.

I will contact the person in charge of the suspension the next day and change the setting. I reloaded the preload of the front suspension back to the initial setting, and on the other hand, I set the rear shock preload by a method that raises it by two turns. I ran it in this state, but the shaking may have weakened but I did not feel a dramatic improvement. So I implemented improvements to the suspension I asked Mr. Shiobara who has experience with the Works team at the World GP '80s. We knew this for the first time.

The first one that I ran with that specification, certainly the effect has come out. Shaking occurs the same, but the starting speed is delayed.
So we added further improvements and after the lunch, the weather was fine when we entered the afternoon course, and around the time we actually started, the wind was the best for the fastest attack.

Since it is not affected by crosswinds, the car accelerates straight and smoothly, and this time it enters the measurement line with the highest car speed.Rolling was occurring from time, but I accelerated further using the rear brake in combination. The strongest rolling from the front occurred when I ran to the measurement section and I could see the exit flag. I raised my body from the vehicle or did not lie down, but the tremors became bigger and I decided that avoiding behavior is impossible. Lock the front brake to full and slip down from the front, I detached from the body of the motorcycle. I continued rolling on the road surface so I could not figure out how many turns I was then, but I rolled up rolling the body with time to think that I should passive while rolling. When asked to the person who was watching from the pit, I heard that my body seemed to be blown at the moment of falling down.

I finally stopped suddenly lying on the ground and stopped since I rolled over. Because the shield of the helmet was broken and lost, sunshine is dazzling, there is not much pain in the whole body as breathing is rough.
An ambulance waiting soon arrives and you can ask a lot of questions, but that does not matter. I had my helmet removed and I was able to stand on my own.

Just before getting into an ambulance, I looked over where I went to the motorcycle, and stopped while turning over over 100 m behind the course. Although I was looking at the distance, the situation was not clearly confirmed, but I thought that it would be fine just to slip well as it was, but after confirming with the pit, the steps and sliders splendidly Thanks to him, the motorcycle did not get caught on the road, it seemed to have skidded cleanly and it was damage on the right side only.

I thought about the cause of the fall over thinking overnight, but I personally think that it is a big factor that the suspension setting was not done properly. Because it seems that if the rear brake is applied and the behavior stabilizes, the shake from the front was less when the load was reduced toward the front side. (There is also a possibility of being wrong)

So this is only speculation, but I think that the front suspension had to be strengthened and the rear suspension should be set accordingly.
In my own race motorcycle, I always prevented rolls. Regarding vehicle weight, my land speed racer is light, so even if the setting of suspension is not enough, I think that I was able to run well so I could prevent it with my body. If you can do so that your body does not receive the influence of crosswinds, the body itself seems to be relatively stable. I think that having brought about this fall was that I was not able to do enough setting because I was helped with the rear brake. Even if Mobitec opposed it, I think that you should consider preloading the front suspension considerably and strengthen the rear suspension as well, or try replacing it with the pen ski you brought. Since this judgment can only be done by me who is a racer naturally, I think that mistake is in myself.

Anyway Bonneville's trial will be greatly affected by the road surface and the weather. If the conditions are met at the moment of attack, the racer naturally opens a bet throttle on that one chance. However, even if it was not impossible, everything will be over if it falls over. Crash is included in the race, but I am truly sorry that everyone who was involved in Mobitec and development ended in disappointing results. Mobitec's executives also came to the site, but I was sorry that the bike crashed in spite of saying that everyone would take a commemorative photo after the race.

I have had experience of falling by motorcycles only about 3 times in my life, but of course I have never rolled at a speed of nearly 300 km/h. The thing that the body was safe is already really a miracle, but it was told to my best friend 's doctor "If you say it normally, it is medically dead". Lol

Many race officials have commented on our FB, but I would like to end this article with a particularly impressed word.

"Your dreams are our dreams and we hurt when you hurt.
Thank you for considering everyone else."

by Rocky Wingwalker. (Thanks Rocky !)

P.S. Thank you so much transtrating "TAKU_san" !!!!!!!!

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