Motorcycles Technology
CBR1000RR-R Engineers Talk
Large Project Leader Yuzuru Ishikawa affirmed, “Our target was a MotoGP machine.” And the development rider Shinichi Ito said, “There is no other motorcycle like this.”
It has been 28 years since the first generation of the “FireBlade” debuted. The super sportbike, “FIREBLADE” has stepped into a totally new world. What kind of path did it take to come into this world?
I explored the words of the development rider and development team members.
Interviewer: Morimasa Sekiya (Mobility Analyst)
Became independent after working for motorcycle magazines and an advertising agency.
Covering vehicles ranging from race machines to commercially available motorcycles based on abundant interview experience on mechanisms, manufacturing technologies, materials, etc.
Felt the difference from the moment I straddled it.
Sekiya:
Mr. Ito, I heard that you had been involved in the project from the initial stage of the development.
What was your impression when you first rode the prototype?
Ito:
My first impression when I got on it was, “Big….”
As the previous model was more compact, frankly speaking, I wondered if this size would be OK.
Sekiya:
What was the explanation of the development team?
Ito:
They told me that Honda’s knowhow on running stability would work effectively on this size, and that it was the dimension to win a race.
Listening to that, I felt, “Wow.”
It was like, I perceived Honda’s unprecedented enthusiasm.
Sekiya:
Generally speaking, it is said that sportbikes should righteously be compact. How do you feel about this opinion?
Ishikawa:
A racer serves as a standard in regard to vehicle stability at the time of entering a corner and when high load is applied.
Then, positions of a wheel base and the center of gravity are naturally determined.
Sure, the new model becomes “bigger’’ than the existing models.
But it does not mean that it is wider or comes with unnecessary design.
The size is a result of the pursuit of ideal circuit performance.
Shinichi Ito
Won the title of the All Japan Road Race Championship in 1990, 1998, 2005, and 2006.
Four-time overall champion in Suzuka 8 Hours, in addition to being on the podium of the FIM Grand Prix World Championship GP500 Class 6 times.
Served as a development rider for the CBR1000RR-R.
Yuzuru Ishikawa (Large Project Leader)
Started his career at Honda in 1993.
Designed frames for models including the CBR1100XX, RC211V, CBR1000RR series, RC213V-S, etc.
Large Project Leader for the CBR1000RR/600RR series, CB125/150/250/300R and CBR1000RR-R.
Owner of a 2012 CBR1000RR and CB150R.
Power, above all.
Sekiya:
From where did the pursuit of ideal circuit performance start?
Ishikawa:
We first looked into what an engine performance target should be.
Our arbitrary approach was to let the engine produce however high power it could to overwhelm competitors, then to investigate what kind of frame could hold the output.
Sekiya:
Alright, please let me ask you about the engine. How did the team proceed with the development?
Mori:
The best example was MotoGP machines.
Even though V4 and inline-4 are different engine styles, with the RC213V bore and stroke as a baseline, we can project approximate horsepower.
Sekiya:
I heard that the target had been to exceed the specifications of the RC213V assembled with kit parts.
Mori:
Yes, it was. We listed required technologies to do so and compiled a presentation to declare the target performance.
But, we started feeling like, “The target was somehow imaginable. Would this astonish customers?”
So, we came up with the horsepower target that we were sure would impress customers.
To tell you the truth, it was our “feeling” that has accomplished it.
Sekiya:
Feeling… what do you mean by that?
Mori:
Heart.
Sekiya:
(laughs)
Mori:
One’s head might as well be empty for stuffing it with dreams. (laughs) When trying to go higher where existing technologies cannot take you, we have to have this “spirited feeling”. Otherwise, nothing can be accomplished.
Ito:
Because that vaunted engine was slow to show up (laughs), the initial testing was conducted with an old engine on a new frame.
Hearing that the new engine would be incredibly powerful, I felt dubious of its capability. Still, I was looking forward to it, thinking if it were true, it would be a big deal.
Deguchi:
Since this engine is designed with a big bore and short stroke, weight has increased in the reciprocating area, and so has the peak RPM. So, pistons have to be lighter in weight. Pistons are manufactured with the high strength material previously used only for the RC213V-S. While the piston is higher in strength, the head is designed with thin walls. The skirt length has been shortened as much as possible.
Ishikawa:
The center duct, as well, is another adopted feature. It is in the same size as that of the RC213V to improve intake efficiency.
As a consequence, the frame was revamped. Because the ignition key at the previous location would have interfered with this massive duct, the smart key had to be relocated to the left side from necessity.
The bonus was the thin and plain top bridge without the key cylinder, like the RC213V. (laughs)
Kensuke Mori (Engine Design)
Working for Honda since 2006.
Belonged to the inline-4 engine design team.
Involved in the CBR1000RR from the 07 model and designs the engine from the 12 model.
Competed in Suzuka 8 Hours as a member of the internal team (Blue Helmets MSC) from 2013 to 2108. (Not in 2019 due to injury.)
Plans to participate in Suzuka 8 Hours on the new model in 2020!
Toshiaki Deguchi (Engine Research)
Employed since 2000.
Mainly worked on the large FUN models such as the CBR1000RR and CB400 SUPER FOUR after the CBR600RR project.
Belonged to HRC for 4 years from 2008 to develop MotoGP machines for 09-12 seasons and to take on engine research for the first year of the RC213V.
After transfer to mass production development, his responsibilities included the RC213V-S and GL1800.
Sekiya's Eye
The FIREBLADE engine comes with the reciprocating system (reciprocating area) in the basic dimensions carried over from the RC213V.
--To be more precise, this engine uses almost the same reciprocating system as the RC213V-S whose valve operations are controlled by a spring instead of pneumatic control with compressed air.
To create an unprecedentedly high power engine for a commercially available motorcycle, it is ideal and very rational to model on the RC213V, the 6-time winner of the MotoGP for 8 years from 2012 to 2019.
Thus, the basis of the bore stroke of the FIREBLADE, 81x48.5mm lies in the MotoGP regulation that the bore size should not exceed 81mm.
It is reasonable to understand that the FIREBLADE engine is the RC213V engine with parallel 4 cylinders arranged in L instead of V.
Since the bore of this engine is the biggest among parallel 4-cylinder engines commercially sold, the layout of bores laterally in a row was a struggle for the team to reduce the engine size.
Another big challenge of the FIREBLADE was to make sure of lubrication from the initial design stage, taking into consideration its use in a race and ensuring durability.
Due to that, materials, surface treatments, and machining are almost at the level of a factory machine. A lot of time and effort were put into the specifications.
For example, bushing at the connecting rod small end is made of beryllium copper; cam shaft and finger rocker follower are DLC coated; and both ends of the crank case (located around the crankshaft large end) are additionally machined to make an oil line.