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"Because I judged that the chassis would become less and less important in the future, my entrepreneurial project was to make the chassis."
This entrepreneurial logic comes from the domestic skateboard chassis startup company Yo-Run Technology (not the original words). Everyone knows that the automotive circle is full of metaphysics, and the chassis suspension is the hardest hit area. In a context where most consumers (and even a considerable number of practitioners) are confused and disdainful to understand what the "chassis" is, such a concise, easy to understand, and easy to spread new concept is easy to have a market.
The chassis went from a few fans to a moment of industry attention, and someone sentenced it to death - such a tragic disc.
Skateboard chassis one two three
The concept of "skateboard chassis" is widely known with the American Rivian electric pickup truck, and then the overseas related startup Canoo was rumored to have an affair with Apple's car, further expanding the reputation of the skateboard chassis. In China, it is said that Yo-Run Technology (hereinafter referred to as Yo-Run), has just released its own skateboard chassis product "UP Super Chassis".
Rivian, note that the suspension as a whole is mounted on the chassis rather than the body, which is a typical feature of non-loaders
Canoo
Yo-Pao does not manufacture the whole car itself, but provides a skateboard chassis to corporate customers who want to build a car. Yo-Pao is also not responsible for the mass production of skateboard chassis, but like a car company, it is looking for factory OEM. If the traditional Bosch and mainland China are called Tier1 (tier 1 supplier, parts directly supply car companies), the role of Yo-Pao can be called Tier 0.5 (although Yo-Pao expressed resistance): take parts from Tier1, and then sell the "semi-finished" chassis to car companies.
The skateboard chassis itself is well understood, that is, almost all the subsystems of the vehicle related to walking are integrated into a separate vehicle body, leaving empty free space on it. In this way, the "upper and lower" body is separated and developed, and any form of body can be developed on the same chassis. The operation of the vehicle relies on in-line control technology, and the steering wheel, pedals, etc. can be placed at will without space restrictions.
Run
The benefits of the skateboard chassis are obvious, with almost all travel-related subsystems integrated into a separate chassis structure. This not only frees up a large amount of upper space for car companies and users, but also allows cooperative car companies to only have the task of designing the internal and external structure of the car body, as well as the intelligent user experience with huge imagination space.
Not only are there much fewer tasks, but development is also faster. The skateboard chassis sold to the vehicle company has completed various verification and calibration work in terms of driving and durability, and the idea of "working hard in one battle" has been brought into full play, and the cooperative car companies only need to complete the development of the body to launch new models. Yo-Pao said that compared with the traditional new models on the same platform, the development cycle was reduced by 6-12 months.
All the necessary parts are hidden inside a flat chassis, and the top can be left to the user, almost without any space limitations. Coupled with the flexibility of the crew's sitting posture thanks to steer-by-wire, the skateboard chassis can be expanded into any body form we know is unknown, from an open-top super to a soliciting minibus – theoretically you can build a small two-story building on the chassis.
Whether it is the appearance or description, the UP super chassis of the yo-yo run is similar to the non-bearer body. In addition, the overseas Rivian is a skateboard chassis + non-loaded body, so Yo-Yo repeatedly emphasizes that its skateboard is not a non-loaded body. The upper and lower body of the UP super chassis is rigidly connected and co-loaded, rather than a soft connection like the non-carrier, only the chassis is loaded and the body is watching the play.
Rigid connection, common force, in the vernacular is "welded together" (including non-welded cold connection).
The core elements of the YO-Y UP Super Chassis are CTC (cell-to-chassis), highly integrated thermal management, pluggable ring EEA (Electrical and Electronic Architecture) and fully in-line chassis. These four technologies are all current frontiers, but none of them must be bound to the skateboard chassis - non-"skateboards" can also be used, Tesla is also making CTC battery packs, and many Tier1s are doing in-wire chassis. (Pluggable EEA is only used by skateboards, mainly non-skateboards do not need to be plugged in.) ）
On the contrary, three of these four items are necessary for the skateboard chassis: without full-line control operation, the position of the steering wheel and so on is limited, and it is impossible to freely adapt to various body bodies; without integrated thermal management and pluggable EEA, the work of the car company when developing the whole vehicle for the second time is too cumbersome, and the significance of the skateboard chassis is greatly reduced.
It is not "only the skateboard chassis has these four advanced technologies", but "with these three technologies can make a skateboard chassis"; not in order to use these four advanced technologies, the skateboard chassis is needed, but only when these three technologies are mature can there be a skateboard chassis - this causal relationship must be clearly sorted out.
As for what 1000km endurance, 2WD/4WD optional, 1000+ TOPS hashrate, L4+ automatic driving capability... It's all all tempting, but it's all about skateboarding without skateboarding: isn't it impossible to achieve these indicators on the skateboard chassis? Therefore, from the perspective of this article, these are not necessary to discuss, and they are not the focus of the skateboard chassis at all.
Three UP SPACE super cabins, translation: three styles of shells
Based on the UP Super Chassis, Yo-Yo-Tro also released the "UP SPACE Super Cabin": three completely different concept bodies developed by Yo-Run itself. The UP SPACE super cabin is not actually a commercial product of Yo-Yo, and its main role is to show and demonstrate the diversity of the up-and-coming body development of the UP super chassis to potential customers.
When we talk about chassis
What exactly are we talking about
To understand the skateboard chassis, we first need to be clear about what the "chassis" is - we talk about it every day, do you never realize that you may not understand it correctly?
In the vast majority of modern family cars, you can't find a single part called the "chassis".
In ancient times, when the non-bearing body was the dominant, the scope of the chassis was clearly defined, and all the walking-related subsystems were installed on the girder/steel pipe frame, so this was the chassis; and when it came to the load-bearing body, the chassis was the body, the body was the frame, and the frame was the chassis, becoming the same thing. Friends who often pay attention to our number and pay attention to this column should be familiar with the carrying/non-carrying body.
Last time in "Why is the car chassis really not a thing?" In the automotive class, some professional friends in the automotive class questioned that "the body in white belongs to the chassis" is wrong, because the chassis system catalog cannot contain the body-in-white, and there will be no textbook that says "the body-in-white belongs to the chassis". There is nothing wrong with this, in academics and engineering, the body-in-white is the body-in-white, and the chassis is the chassis.
Note, however, that (even academically) the chassis consists of a drive train, a driving system, a steering system, and a brake system, of which the driving system also includes the "frame". For non-loaded bodies, no one will overlook that the frame/girder is part of the chassis. In the era of the load-bearing body, the "frame" was integrated with the body-in-white and physically disappeared. Nominally, the "frame" can no longer be found in the "chassis", and functionally, the body-in-white body that plays the role of the frame has essentially become part of the chassis.
Therefore, academically, the body in white is the body in white, the chassis is the chassis, how to do it. But when we talk about the chassis of a specific car, we can't ignore that the body-in-white is also part of the chassis function. If it is said that the non-carrier body undertakes the chassis function, it is a girder frame with various subsystems installed, then is it said that the load-bearing body plays the role of the chassis, is it just a bunch of subsystems scattered throughout the vehicle?
When we evaluate the comfort of a car's chassis, can we ignore the impact of the body-in-white on NVH? When the stiffness mode pulls the crotch, no amount of acoustic insulation cotton will help. When we evaluate the handling of a car's chassis, can we ignore the impact of the body-in-white on dynamic performance? When the limit deformation is too large, even the most perfect suspension will be abandoned.
To clarify this, we might as well take a look at how to build cars without "skateboarding" today.
Platforming is already an overspoken concept. In short, in order to produce collinear lines, universal parts, and rapidly derive new models, car companies have made great efforts to develop a basic body that can adapt to a certain range of dimensions (mainly wheelbase), sitting height (sedan/SUV), performance level (power range & suspension configuration, etc.) in advance, which is the model platform.
This basic platform usually plays the main role in defining the lower half of the body-in-white, because the upper body needs to be designed separately for different body forms, and the lower half of the body-in-white is also more influential on the performance of the chassis. Therefore, when car companies display platforms, the exhibits are usually a look that looks like a "chassis":
Can such a base platform be called a "chassis"? Strictly speaking, it can't, because if the platform is not pre-designed for "no roof", then the strength and stiffness of the upper body of the car are not up to standard/not up to the design requirements. Getting out of the car may not be able to drive, but calling it a chassis is a foul-style belittling of the platform — people have no intention of selling such a naked car to consumers.
Whether it is for the performance of the whole vehicle, or for the crash safety performance, the lower body of the basic platform has never intended to fight alone, and it is necessary to cooperate with the upper body of the specific model to be a complete bearing-on-white body, that is, the chassis (frame). With the B-pillar and the top beam, we can talk about side collisions; with the ring-shaped torsion-resistant structure that spans the roof, we can talk about stiffness.
Having said so much, I can finally lead to a sentence: the upper body is also an inseparable part of the chassis (load-bearing body). It is related to crash safety and vehicle stiffness, the former is the basic quality of a manned car, the latter determines the positioning and level of the vehicle; and these two requirements, in turn, will determine the weight/weight of the body and even the vehicle, affecting a series of performance and energy consumption.
Freedom without cost, does not exist
Getting on the car body is related to the personal safety of the occupants, which is enough to put any "low threshold theory of car building" on death row. Especially when the upper and lower body of the UP super chassis is integrated (physical) to live a life, the development and design of the upper body can not only not relax, but also need to adapt to the skateboard chassis below.
In the case of collision safety, the UP Super Chassis contains only front and rear anti-collision stringers, neither B-pillars nor front cushioning structures (not to mention anti-rolling at the top). Car manufacturers not only need to find their own way to pass the crash test, but also cooperate with the UP super chassis to design: you definitely don't want the bottom of the car to be much stronger than the upper part, and let the other party jump over the chassis and pound the car body when colliding...
Not to mention situations such as 25% bias collisions, where the front stringer is almost completely unable to function, the skateboard chassis is all about the car body.
Speaking of body stiffness, the skateboard chassis itself has a certain degree of stiffness, and the rigidly connected upper body can also contribute some. However, if the stiffness of the UP super chassis is fixed (or the variable range is very small), then the stiffness of the upper body has a most appropriate range: if it is too high, it may be limited by the chassis stiffness and cannot be played, and if it is too low, it wastes the cost under the chassis stiffness.
This is another restriction on the design freedom of the vehicle, and there will be an ideal optimal range for the stiffness of the vehicle, and if the interval is deviated, it will not be possible to make perfect use of the cost of the skateboard chassis and body.
Of course, all this yo-yo can provide reference standards or even do the work, but every additional collaboration process is a damage to the "shortening cycle", and each additional restriction standard is a damage to the "freedom of car building". A car builder who thinks that he bought the chassis and built the car casually, maybe he will finally find that he bought a set of vehicle solutions...
Originally, the task of cooperative car manufacturers seemed to have become simple and free, and an industrial design student could draw one, but in fact, as long as it was a passenger car used on public roads, the threshold would not go anywhere. Take the chassis body can be built at will, only suitable for community low-speed commuter cars, express container cars and the like.
Shoot the MEB back and forth, and you get a skateboard...
If you ignore the CTC, wire control and other technologies that are not exclusive to the skateboard chassis, since the upper and lower car bodies also have to be rigidly connected to "weld up", then compared with the traditional model platform, the UP super chassis can actually be regarded as a special platform where the front and rear parts are "flattened".
Getting off the car body is flattened naturally will greatly increase the space above, make the upper part flat, and achieve a highly flexible space layout, but this "flattening" action is not without cost. The top of the suspension of the skateboard chassis should be mounted on the chassis instead of the body/upper body, so that the height of the suspension top is greatly reduced - if the suspension is reduced without any compromise, how can such a good thing make you think of it first?
The front and rear suspensions of the yo-yo run can be described as survival in the cracks
Everyone knows that there are many types of suspension structures, and different types of suspension occupy different spaces, but there is a commonality: longer connecting rods and larger size often mean more precise wheel control, and it is often necessary to pay higher costs or more weight to reduce the volume without affecting the performance.
This is true of the connecting rod structure, which is limited to space, and especially the stroke of the spring and the shock absorber. A significant feature of S-class, 7 series and other executive-level luxury cars is that the top height of their rear suspension towers is close to the lower edge of the rear windshield, and the stroke of the spring shock absorber is increased as much as possible to improve the delicacy of the suspension and increase the adjustment space.
Mercedes S-Class, note the rear suspension spring volume
The height of the rear tower top of the Lucid Air
Of course, the skateboard chassis does not necessarily have to pursue the suspension travel of such a high-level model, but you can see from this example that the height and volume of the suspension are directly proportional to its performance.
The rear suspension of the Canoo skateboard chassis, which uses a vane-type composite spring similar to the Volvo SPA platform, reduces this contradiction to some extent. But the short stroke of the shock absorber is not essentially solved, Canoo (yo-yo is also) will be the shock absorber as oblique as possible, but the oblique position will have a diagonal suspension geometry problem, not expanded here, the reader of this article should be able to understand what "physical geometric limits" mean.
Canoo's rear suspension springs
As for the UP super chassis of yo-yo, all you can see is that the spring shock absorber is simply shortened, and the resulting suspension performance limit will greatly reduce the comfortable bandwidth and performance bandwidth it can cover. Thus, although the skateboard chassis nominally seems to be able to give birth to everything, this freedom in the range of spatial form comes from the limitation of the performance range.
It can be derived from various models such as cars, SUVs, and vans, but the performance of the chassis is limited to a narrow range, and the performance of the chassis determines the upper limit of the power performance. With a full body, NVH comfort and handling are congenitally inability to be improved, and the derived models can only fall on a narrow range of positioning levels.
Ideological and political teachers have long taught us that there is no absolute freedom, only relative freedom.
Canoo, anything can change, except for the wheelbase
This infrequency is even reflected in the wheelbase. Like Canopy's skateboard chassis, the wheelbase of the UP Super Chassis is basically immutable, and it does not have a large "bandwidth" like the model platform, and the body shape does not include length and width dimensions in the freedom of body form. It should be known that the new generation of platforms of large car companies can often cover cars, SUVs and even more models that span more than three levels, which is one of the important reasons why the platform development cycle is as long as several years.
So much so that there is a strong call for yo-yo running: the automotive industry should eliminate the "old thinking" of "too much emphasis on wheelbase". Such a line of thinking is very creative, but the business has the law of business, and the consumer has the preferences of the consumer, which will not change with any change of the times.
Car companies need wheelbase to provide subdivision models, need wheelbase to divide the level of high and low, need to give low-level models "knife" to highlight the value of high-level models, "equal rich and poor" has never been the antidote to class. Consumers are different from each other, some consumers need small cars, some consumers need large cars. This is the most basic need, and it is not the chassis skateboard that is not skateboarded, the car is not intelligent, and the era can be reversed without change.
If only there were a magic wand
Rivian and Canoo are typical of skateboard chassis, but neither of them has the ambition to run. Rivian's two models are non-body-bearing pickup trucks and SUVs, and their skateboard chassis and body are as soft as fuel non-carrier pickup trucks. This means that The Rivian chassis will only produce non-bearer models, which is not a problem considering that its market is mainly North America.
The Canoo is the main van, and the resulting pickup trucks, trucks and so on. There is only one passenger car in the preview, but it is the only model in Canoo that does not give a production schedule. The company's product line, at least in the early stages, focuses on van-shaped passenger and cargo transport vehicles, and the scope is limited to this. Another skateboard chassis company, REE, has its main focus on "sinking" to delivery trucks and community commuter cars, and passenger cars are just pre-research exploration.
The skateboard chassis certainly has its own value.
On the one hand, skateboard chassis is well suited for vehicles that don't require all-round performance, the most extreme example being a community low-speed commuter car. They don't need good walking performance, don't need to cope with all kinds of road surfaces to cope with high speeds, don't need high standard crash tests, and space and body flexibility are almost the only things that matter. The skateboard chassis is perfectly adapted to this type of vehicle, which is also the reason why the skateboard chassis companies represented by Canoo and REE have started with vans and commercial vehicles.
On the one hand, if you have to build a conventional passenger car like Yo-Yo- Pao, there must be a most appropriate range: performance, orientation, price and positioning. Rivian has found the sweet spot of its own skateboard chassis, and the current model of this skateboard chassis is limited to traditional brother cars such as pickup trucks and SUVs.
In the vicinity of a skateboard chassis "sweet spot", a limited number of models can be obtained that do not compromise on the basis of the skateboard chassis; in addition to the "sweet spot", the output model will be sacrificed in some aspects: it may be that some performance cannot catch up with the competitors of the same level, or it may be a loss in some aspect of the excess performance cost. To make a wider range of models perfect, it is necessary to sacrifice the degree of generalization of the chassis, and then lose the original cost advantage.
In the mainstream family car world, all aspects of vehicle performance have been rolled into the extreme of various eras as early as decades ago, and any compromise, sacrifice and redundancy made because of concerns about cost and versatility will be taken to the spotlight by discerning consumers.
Of course, just as models that do not have the advantage of product power will not die immediately, skateboard chassis is not completely without a market outside the sweet spot. It greatly reduces the development cost and time of car companies, and may also gain scale advantages, which is also dominant in cost. But in doing so, it is also doomed to become a temporary solution for some non-head car companies (except for those who fall on the "sweet spot"), or a tentative or ticket-playing work of some non-car companies, which is probably contrary to the original intention of Yo-Run to create a UP super chassis.
Generalization and flexibility are a pair of essential contradictions, and today's popular platformization is the product of trade-offs in contradictions, and it is the result of the balance between versatility and versatility, cost and competitiveness. To have a strong enough compatibility and derivation ability, to make completely different models have enough competitiveness, but also to meet the requirements in the versatility and collinear capabilities of parts, there must be a sacrifice behind the take.
Even today's many mature platforms have their own dead ends where the power of their products has plummeted, and they also have limits that they dare not even touch. If BMW develops the 1 series based on CLAR, it is self-inflicted, and Audi dares to build A9 on mlb Evo, which is higher than the sky. Not to mention the resources consumed to develop the platform, and the development cycle that is still years long under such resources.
That's still the case with the platform, not to mention the more cured skateboard chassis. A skateboard chassis with wheelbase, stiffness, suspension, and power are all limited, how to develop a variety of models of high and low levels; a skateboard chassis based on the development of different levels of distance and proximity, how to make the product strength of each model is not much in line with the pricing; a chassis that can freely adjust different configurations according to model positioning, level, and orientation, so that each model has a good competitive chassis, and how to achieve a high degree of generalization and achieve dilution cost and rapid research and development.
Friend, do you believe in magic?
The technology itself is neutral, the skateboard chassis is the perfect solution for commercial vehicles, and it is not completely illogical to build passenger cars, but it is a fool's dream to think of it as "the future black technology that will change the rules". CTC, wire control, etc. are indeed new technologies, but none of them are born because of the skateboard chassis, nor are they attached to the skateboard chassis and exist, there is no skateboard chassis Everyone is the same CTC, the same wire control.
The skateboard chassis has changed from a non-mainstream car-making method to a popular field for the capital market, which is fundamentally inseparable from today's overheated car-making tide:
Surgery today... Oh no, build a car today, get on the road tomorrow. Just ask you if your heart is not moving?