Honda CB400 Super Four E Clutch Concept, unveiled for the first time at the Osaka Motorcycle Show on March 20th. Although it's called a "concept," visitors were allowed to sit on it freely at the show, making its release a certainty. There's no doubt it will be one of the biggest topics of the year. Here's the interview with the developers, conducted about a month before its official announcement.
⚫︎Photos: Atsushi Sekino / Editorial Department
Table of Contents
A 400cc Four-Cylinder as a "Communication Tool"
Mr. Hashimoto, who served as deputy development manager for this model and its sibling, the CBR400R FOUR E Clutch Concept, has previously worked on the development of models such as the CB250R, CBR650R, and overseas models. In his private life, he has experience racing the CRF250R, a model he was involved in developing. He is currently considering which of his developed 400cc four-cylinder bikes to keep as his personal ride!

Webike Plus (hereinafter W): Ever since the "CB500 Super Four" (local specification) debuted at a show in Chongqing, China, in September 2025, we at Webike Plus have been in an uproar. We've published many articles, and the page views have been overwhelmingly high. It was undoubtedly the most talked-about new model of last year.
Takaaki Hashimoto (hereinafter H): Yes, we saw them. Thank you.
W: So, we're putting a lot of energy into this interview (laughs). To start, please tell us about the development background of the CB400/500 Super Four. What led to the development of these models?
H: There were voices calling for a 400cc inline-four that could meet Japan's increasingly strict emission regulations. At the same time, Chinese local manufacturers were steadily selling more four-cylinder models. In China, young people in their late teens and early twenties gather at touring spots on such bikes, chatting and showing off their motorcycles.
W: It sounds like the same enthusiasm as Japan's racer replica boom era.
H: Yes. However, in China, it's more about fashion and a communication tool than speed. Seeing that really inspired us, and we thought, "What if we combine the situations in China and Japan, could we create a new inline-four model?" That's how the project started.
W: The previous model, the CB400SF (NC42), was discontinued in 2022. Even then, there were many voices hoping for a successor, but was it difficult to revive it solely for the Japanese market due to sales volume?
Hashimoto: I can't say everything, but as you can imagine, the cost and equipment that can be invested are determined by sales volume. While there were many discussions about whether the product would only be for Japan, the situation in China became a major catalyst.
W: So, did the project, which started by combining the situations in Japan and China, begin with the idea of creating a successor to the CB400SF?
Hashimoto: No. The initial concept was to "create a full-cowl type that would be accepted by young people in China." Chinese people like flashy things, and full-cowl bikes are very popular. The market size is about 10 times larger than for naked bikes.
W: So, the focus was on a 400-500cc class full-cowl inline-four, meaning the sibling model, the CBR400 (500)R FOUR, was the main focus?
H: Yes. It's a class with slightly less displacement than the CBR650R series. In China, licenses for 150cc and above are free of displacement restrictions, but when Chinese people get a license, they often jump straight to the 500cc class. Unlike in Japan, they often don't go through the 250cc class first. Considering these gaps, we thought about what kind of characteristics a bike that people could ride for a long time would have.
W: So, the naked type, or the CB400/500SF, was added to the development later?
H: Yes. If we were to sell it in Japan, naturally, there would be demands for a naked version. It's common to share parts and use that volume to differentiate models for each country, so we were considering that. Therefore, while the naked version was added later, we were also carefully assessing the optimal timing.

The new CB400SF and CBR400R FOUR are sibling models, but the CBR was the initial concept, with the naked version added later.

The previous CB400SF (NC42), discontinued in 2022. Upon its discontinuation announcement, used bike prices soared, and many voices called for its return.
W: I see. However, right in the middle of Honda's development, Kawasaki released a striking 400cc four-cylinder bike, didn't they?
H: Yes, it was striking. We learned a lot from it (laughs).
W: The Kawasaki Ninja ZX-4R, announced in 2023, is a highly specialized model with a maximum output of 77ps, the highest ever for a 400cc. However, this CBR400R FOUR is not an "RR" indicating Honda's supersport, and it seems to be an all-around sports model. Was this direction decided from the beginning?
H: Yes. As I mentioned earlier, Chinese customers are not looking for speed; they want something with flashy fairings as an extension of their communication tools. While specs are expected, we believe that a bike that can be enjoyed for a long time cannot be made on specs alone. We planned and developed it with everyday use in mind, such as in the city, on tours, and on winding roads.

Kawasaki's Ninja ZX-4R, announced in 2023, also targets the Chinese market. Its 77ps, the highest for a 400cc, was a shock to Honda, but the "all-around sports" axis of the new CB/CBR remained unchanged.
W: Let's go back a bit, but was the inline-four engine a given from the beginning of this model's development? If so, what was the reason?
H: We already have twin-cylinder models in our lineup, and we wanted a vehicle that would take things a step further to express Honda's unique character.
W: I understand. By the way, there are both 500cc and 400cc versions of this model. In terms of sales volume, is the 500cc version expected to be higher?
H: Considering the market scale, I believe that will be the case.
W: Will it be sold in regions other than China and Japan?
H: Nothing is decided yet, but we would like to offer it widely to other countries if there is demand.
Bore and Stroke Both Specialized for 400cc
W: Next, please tell us about the differences between the 500cc and 400cc versions. The CB500SF has a displacement of 502cc, while the new CB400SF has a displacement of 400cc (detailed displacement not yet announced). Is this difference achieved by changing the bore and stroke, or both? Also, the bore and stroke of the 500cc are not yet announced.
H: It's difficult to answer since it's not announced... Please forgive me for not providing specific bore and stroke figures (laughs).
W: Considering it's an all-around sports model, the low to mid-range torque cannot be ignored. Also, the displacement is reduced from 500cc to 400cc. Wouldn't it be more advantageous in terms of output characteristics to have a longer stroke tendency with reduced displacement?
H: The answer is that we changed both the bore and stroke from the 500cc version. We optimized it according to what is required. While the stance is based on the 500cc customer, we decided from the perspective of what it should be for the Japanese 400cc customer.
W: I see. If it were a simple displacement reduction, changing only the bore or only the stroke would be more cost-effective. However, I will interpret this as optimizing both bore and stroke for the 400cc to pursue the characteristics of Japanese users. Furthermore, regarding the maximum output, for the 400cc version, will it exceed the 56ps of the previous NC42?
H: As a Honda characteristic, we believe we need to meet a wide range of customer expectations to sell well.
W: Users might be hoping for something that surpasses Kawasaki's (laughs).
H: I might have overstated that (laughs).
W: So, will the specifications be lower than the 500cc version?
H: Since the displacement differs by about 1.25 times, the output will naturally differ. This is a "concept" model, so please look forward to the details.

If the 500cc version has 71PS, a 20% reduction in displacement for the 400cc version would theoretically be 56.8PS. This is not much different from the NC42, so will it reach the 60ps range?
W: I understand. But please tell us more about the engine. Why was it made completely new, with no relation to the previous NC42? From an amateur's perspective, wouldn't renewing and using the NC42 engine be an option?
H: There are two main reasons. First, the current emission regulations have become more stringent, and meeting environmental performance requirements necessitates changes to the engine specifications. Second, we delved deeply into what a standard sport naked bike should be in modern times, and it required a renewal of its performance and specifications.
W: With these two major reasons as a premise, what changes have been made to the engine concept? Comparing it to the NC42, we can see that the main three shafts of the engine are in a triangular arrangement, reducing the front-to-back length, the center cam chain has become a side cam chain, and the oil filter, which was previously in front of the crankcase, has been moved to the underside of the engine.

Comparison of the previous (left) and new engines. The configuration has been completely renewed, including the upward movement of the clutch (i.e., triangular arrangement of the main three shafts) and the adoption of downdraft & side cam chains.
H: As this is still in the concept stage, we cannot disclose technical details yet. However, when creating a new Super Four, the previous model, which has been accepted for 30 years, is naturally something we cannot ignore; it's a great teacher.
By analyzing the essence of what has been accepted, we find ease of use, a wide range of acceptance for anyone, the enjoyment of variable systems like VTEC, and versatility for carrying luggage on camping trips. We have re-examined these essential qualities and rebuilt them with modern technology in this new CB400 Super Four.
As one element of this, we incorporated the thinking of what kind of specifications and component layout would be necessary to achieve ease of use and a wide range of acceptance for the engine. This is the form it has taken.
W: I see. I'll look forward to more specific details later.
H: Regarding what can be seen from the exterior, this model is equipped with an E Clutch. Its placement and configuration are not on the right side where a clutch would easily fit; we discussed that with a new engine, there are things that should be done, and this is the current placement. In previous E Clutch models, it was on the right side of the engine, attached to the clutch cover. In the new CB400SF, it's placed on the back of the crankcase, so to speak.
W: It looks like an L-shaped configuration, covering from the top of the crankcase to the drive sprocket.
H: Yes. Additionally, the clutch lifter is pushed by a pushrod from the left side of the engine. By effectively utilizing parts from existing models, we believe we have achieved the optimal configuration for an inline-four.
W: While the previous model protruded slightly, this E Clutch is so integrated that you might not notice it's there – that's a bit of an exaggeration, but it's that seamless. By the way, will a manual version without the E Clutch be available?
H: This model is a concept model equipped with the E Clutch.
W: I see (laughs). Regardless, I've heard that for existing E Clutch models like the CBR650 series and Rebel 250, 80-90% are E Clutch versions. Seeing those numbers, I personally think the possibility of the new CB400SF being E Clutch-only is not zero.

The E Clutch on the new CB400SF is placed above the crankcase. The unit itself is common with those used on the CBR650 series and Rebel 250.
Enjoy "Variability" Even Without Hyper VTEC!
W: Compared to the previous engine, the Hyper VTEC is not used this time...
H: It is not.
W: Hyper VTEC, which switches between 4-valve and 2-valve operation and provides exhilarating acceleration at high RPMs, was a symbolic mechanism of the previous CB400SF. What is the reason for not adopting it?

Introduced in the 1999 model change, "HYPER VTEC" evolved into "SPEC II" in 2002, "SPEC III" in 2003, and finally reached the FI-equipped final version, "Revo," in 2007. It was loved as a symbolic mechanism of the CB400SF.
H: We understand that Hyper VTEC was a major element of the CB400SF's appeal. However, considering current road conditions and environmental factors, we felt that the situations where its benefits could be fully realized were very limited.
It's exhilarating when it switches to 4 valves. But once you experience that exhilaration, it can be stressful to keep riding in the 2-valve range... In typical touring speeds, you spend most of your time not engaging VTEC. So, we questioned whether we were truly providing the "joy of variability" to our customers. Therefore, we have expressed Hyper VTEC in a different form and introduced it to the new CB400SF and CBR400R FOUR.
W: A different form? What is it?
H: Specifically, we focused on the intake sound. In the previous model, the engine had horizontal intake, and the air cleaner box was under the seat. In the new model, with downdraft intake, the box has moved to the front of the bike, closer to the rider's ears. By utilizing this, we have worked on the new CB400SF by varying the length and cross-sectional area of the air cleaner ducts on the left and right sides to create sounds that are easy to hear at low to mid-speeds and sounds that are easy to hear at mid to high speeds, as well as their harmonies, allowing the rider to hear a clear intake sound.
W: Is it like an "Intake Sound VTEC"?
H: It doesn't vary (laughs), but we want to convey the rider's intentions to the motorcycle properly and allow them to savor the feedback. The intake sound changes according to throttle operation. By providing such a range from low RPMs, we've created it so that you can experience the joy of variability like VTEC.
W: With just a twist of the right hand, the sound changes more and more...
H: This time, we've included TBW (Throttle By Wire) and riding modes. This allows for variations based on those, and with the E Clutch, we have a blipper function. This allows you to enjoy the inline-four sound through the blipper even during deceleration, and we've developed it so you can experience the variability of an inline-four in all riding environments.
W: Existing E Clutch models like the CB650R and Rebel 250 have cable-actuated throttles, and engine braking during downshifts was managed by controlling the clutch. However, with the combination of E Clutch and TBW, including the blipper you just mentioned, how has the control and riding feel evolved?
H: We can better utilize the characteristics of each riding mode. This time, we've included three modes: "Sport," "Standard," and "Urban" (plus a customizable "User" mode). In "Urban" mode, the TBW and E Clutch characteristics are finely tuned to make riding in city traffic jams easier. Specifically, by reducing the throttle response, you can repeat starts and stops without worrying about your right hand's operation in traffic jams, leaving your left hand free. We envision a world where you can go to school or work the next day without fatigue from touring, and think about where to go next week... a world with such余裕 and vitality.

The new CB400SF features three (plus two user) riding modes. If you select "Sport," can you experience an acceleration feel similar to HYPER VTEC?!
Simulating VTEC with Electronic Control?!
W: One more thing I'd like to ask about the engine is the four-pipe exhaust, reminiscent of the "Yon-For" (CB400 Four). What was the intention behind that?
H: The length of the exhaust pipes can affect performance, so there are unequal length models. However, when thinking about a clean sound that is characteristic of an inline-four, we felt that style was appropriate.
W: The exhaust pipes of the 650 series have a similar image. For the 400cc version, can we consider this an homage to the originator of Honda's 400cc four-cylinders, the CB400 Four?
H: We were inspired by it (laughs).
W: If you said you weren't inspired at all, that would be a lie (laughs). In any case, it feels like an item that emphasizes the "essence of Honda's 400cc four-cylinder" like nothing else. While there are many CB400SF look-alikes in China, this is a point that can appeal to Honda's origin.
H: However, during the process of meeting emission standards, that shape was almost compromised. But we decided this was something that needed to be preserved.
W: Was the silencer also designed with the flowing style of the Yon-For-style exhaust pipes in mind?
H: Yes. The muffler is determined by various factors such as design, noise regulations, and output characteristics, so we aimed for a shape that balances all of these.

The exhaust pipes of the new CB400SF, with their beautiful curves converging in a single line, strongly emphasize the inline-four character.

Arguably the most beautiful exhaust pipes in Japanese motorcycle history, the CB400 Four's pipes have remained timeless for over 50 years since their debut in 1975.
Over 10kg Lighter Than the Previous NC42?!
W: Next, please tell us about the chassis. Compared to the previous model, the double cradle frame, conventional forks, and twin shocks have been replaced with a diamond frame, upside-down forks, and a linkage-type monoshock. Was this configuration decided from the start to accommodate the main focus on a full-cowl design?
H: It wasn't decided from the start, but it's true that we were generally moving in that direction. However, when we considered the Japanese market and what a successor to the Super Four should be, there were, of course, discussions. What is important for this vehicle? What is the essence of what the CB400SF has been recognized for? We decided on the current form after discussions about what means to choose.

The previous CB400SF evolved without changing its double cradle frame, which surrounds the engine, and its combination of conventional forks and dual shocks since the first model in 1992.

The new CB400SF features a diamond frame without an under-loop, and its suspension has been modernized with upside-down forks and a monoshock.
W: This is a bit of a personal comment, but I (interviewer Matsuda) love the previous CB400SF. It has an incredibly wide range of usability, allowing riders of any skill level to ride with confidence and enjoyment. Of course, the VTEC engine is fun, but the abundant feeling of ground contact and the bike's enveloping nature are simply superb. Naturally, the discussion must have been that such qualities are absolutely essential for the new CB400SF as well, right?
H: Yes. It is naturally essential, and furthermore, I believe it has evolved to another level. This is because the new model is significantly lighter than the previous one. Lightness is truly justice, not only in cornering but also in straight-line riding and maneuvering. We believe that by reducing weight, we have been able to better express the essence of the CB400SF this time.
W: In what areas has this weight reduction been achieved?
H: It's an all-new design, so it's everywhere. Of course, the engine is central, but the chassis is the same. It's lighter by two digits than the previous model.
W: Two digits?! Lighter by two digits than the NC42?! Two digits... that means at least 10kg, right?
H: We can't disclose the specific figures yet, but we've achieved significant weight reduction (laughs).
Honda Public Relations: You'll notice the difference as soon as you maneuver it; it's completely different. It feels like a 250cc class for a moment (Note: Reporters were not allowed to touch or sit on the bike at the time of the interview).
H: The difference is noticeable the moment you lift the bike, you'll say, "Ah, this is different." It's not just the absolute weight; as indicated by the E Clutch placement, it's a completely new design, allowing us to place heavy components appropriately. Compared to other bikes of similar mass, it feels lighter than its numerical value suggests.
The 500cc Version Weighs 188kg!
At the Chongqing show in late March, the sibling model CB500SF was announced with a curb weight of 188kg, which is 13kg lighter than the previous CB400SF (final NC42 model) at 201kg. The new 400cc model should have a similar weight. Even with a completely new design, this figure is remarkable, especially with the E Clutch equipped (existing models gain 2-3kg). Significant improvements in chassis performance can be expected.
Very Slim Below the Crotch. Good Leg Reach.
After this interview, at the Osaka MC Show that opened on March 20th, we had the opportunity to maneuver and sit on the bike. The effort required to lift it off the side stand was clearly lighter, and the ease of maneuvering felt like it set a new standard for 400cc bikes.
Furthermore, the good leg reach was impressive. This is due to the slim design around the side covers as part of the new chassis design. Specifically, the width of the seat rail has been narrowed, but this space is used to house the battery and other electrical components, leading to struggles with space allocation. For details on leg reach and other aspects, please see the article below.
A LCD Meter for Young Riders
W: Next, please tell us about the design. Although the chassis configuration has changed significantly with the diamond frame and monoshock, it looks unmistakably like a CB400SF from any angle. It feels very well-balanced.
H: In a way, the order was reversed. The starting point of development was "long-loved, orthodox naked styling," and the name "Super Four" came later. So, we incorporated iconic elements as essences and emphasized them further...
W: Earlier, you mentioned that the full-cowl concept came first, and the naked version was added later. But even at the naked version's starting point, wasn't the goal to "create a Super Four"? If so, could there have been possibilities for a streetfighter-style naked bike?
H: If there were many customers seeking that direction, perhaps. However, we currently perceive that there are many customers seeking authentic naked bikes in both China and Japan. Based on that premise, we aimed to create a standard sport naked bike that meets the demands of the current era, and the name "Super Four" was applied to that concept.

紆余曲折はあったようだが、結果的には「ザ・スーパーフォア」と呼べるスタイルを得た新型CB400SF。タンクの造形はその最たるものだ(詳細はこちらの記事).
W: I see. But as a result, I feel it has become the most familiar styling for Japanese users. And that leads me to ask about the square LCD meter, like a smartphone. Was it decided from the beginning to go with an LCD meter, rather than the traditional bullet-shaped analog meters of the previous model?
H: Yes. As digitalization progresses, the value provided by meters is expanding beyond just instrumentation, including smartphone integration. Also, this bike needs to attract younger customers. With smartphones being an integral part of daily life, we chose this meter because it's easily accepted and offers the desired functionality.

It was adopted with smartphone compatibility in mind and may become indispensable once you experience its convenience!
W: Like its sibling, the CBR400R/500R Four, the new CB400/500SF also has a strong intention to target younger riders, doesn't it?
H: Yes. Our Chinese customers are generally young, and for many, this is their first motorcycle. We want them to get into motorcycling, think "motorcycles are really fun," and continue a life with motorcycles for 10 or 20 years. Therefore, we are strongly conscious of their values. Furthermore, our generation tended to cherish things earned through hard work...
W: Today's young people tend to turn away if they can't get what they want easily and quickly.
H: Yes. Values have changed, so we believe it's very important that they can easily enjoy a 400cc inline-four without stress and immediately.
W: The LCD meter, which is compatible with smartphones, is one example. By lowering the barrier to entry like this, you aim to let people know "how good Honda's CB is!" even in the competitive Chinese market, right?
H: It doesn't have to be limited to Honda. We believe that as the top market share manufacturer, we have a role to play in the shrinking motorcycle market.
W: I see. Regarding production, since the Chinese market holds significant importance, how will the vehicles be produced? I assume the 500cc version will be produced in China, but will the 400cc version be produced at the Kumamoto factory in Japan?
H: We will choose the most suitable location for the Japanese specifications.
W: Honda's current motorcycles sold in Japan that require vehicle inspection are basically produced at the Kumamoto factory. I will assume that the new CB400SF will also be produced there (laughs).
Will the "God" Arrive Under 1 Million Yen?!
W: Lastly, please tell us about the differences between the 500cc and 400cc versions. Of course, the engine internals are different, but externally, the only noticeable difference is the number on the side cover emblem.
H: You can basically consider the differences to be solely related to license class and legal compliance. We also believe it's important to achieve an accessible price by leveraging mass production volume.
W: Is it the tires? The 500 announced at the Chongqing show last September used CST (a brand of Taiwan's Cheng Shin Tire), but this concept vehicle is equipped with Pirelli Diablo Rosso 4.

The CB400SF E Clutch Concept announced in Japan is equipped with Pirelli Diablo Rosso 4. Using Pirelli on a mid-size Honda is also unusual.
H: Since it's still a concept, I can't say for sure, but we are naturally conscious of how customers will perceive it, so we are considering how not to disappoint their expectations.
W: So, it means that tires that Japanese people will appreciate will be standard equipment? I understand. ** And what about the price? What will it be, precisely?
H: That has not been decided yet.
W: I see. However, I can make an estimate based on the current lineup. The twin-cylinder CBR400R is currently 863,500 yen. This time, an E Clutch version has been announced, and based on past examples, it's usually about a 50,000 yen increase. The four-cylinder CB650R with E Clutch is 1,089,000 yen. Therefore, I would expect it to be around 950,000 to 980,000 yen, under 1 million yen.
Honda Public Relations: From a sales perspective, we are aiming for a bike that appeals to customers in their 20s and 30s, and possibly even teenagers. If it's not an accessible price, it won't serve its purpose.
W: We will look forward to that with great anticipation.

Assuming the CBR400R E Clutch is around 900,000 yen... the new CB400SF is predicted to be around 980,000 yen!
W: Lastly, this is a bit of a tangent, but at last autumn's Chongqing show, you displayed a large number of previous CB400 Super Fours, strongly emphasizing their 30-year history. I hear that a considerable number of used CB400SFs are circulating in China, and the model holds a legendary status there.
H: Yes. I've heard it's called the "God Bike" there.
W: God Bike! So, there's a background like that behind its introduction to China this time?
H: It has become one of the starting points for the current boom in motorcycle culture in China. Local manufacturers have created vehicles with accessible prices, exterior performance, and engine types that local people can afford, which has greatly expanded the market.
W: There are many CB400SF look-alikes in China. It seems like after imitating the "God Bike," the real "God" has arrived...
H: As I mentioned earlier, most bikes in China are sportbikes with fairings, and the concept of a standard naked bike doesn't really exist. A model like the Super Four, in that context, was likely received with a sense of novelty.

Scene from last September's Chongqing show. Previous CB400SF models were displayed surrounding the new CB500SF.

中国のZX MOTOが販売する「500F」. The 470cc inline-four produces 73ps.
W: This is another tangent, but the Nissan Skyline GT-R (R32-R34) was basically only sold in Japan. However, the popularity of the game "Gran Turismo" globally sparked interest, with rumors spreading about "an amazing car in Japan," which contributed to its popularity overseas. Is the situation somewhat similar...?
H: It might be similar.
W: While its scarcity may have contributed to its deification, the previous CB400SF possessed abilities and charm worthy of being called a god. I look forward to the day I can test ride the "God" that has descended once again. Thank you very much!
Has the Main Strategy in China Shifted to CB?
Body Colors Available in All 4 Colors
The color variations announced at the Osaka & Tokyo MC Shows are these four colors. The white was revealed for the first time as a Japanese specification. The production model is expected to have the same lineup.
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