Systematically sort out the "skateboard chassis"

1. Introduction

In recent years, as competition in new energy vehicles has become increasingly fierce, the iteration speed of new models launched by various manufacturers has become faster and faster. The previous pace of traditional car companies launching a new model every 3-5 years has become increasingly unable to keep up with the development of the times. After traditional car companies have successively launched pure electric models based on modified existing fuel vehicle chassis, they are also facing the problem of acclimatization.

Based on this situation, in order to better meet the demand for pure electric models and develop new models faster, mainstream car companies and start-ups have turned their attention to the field of skateboard chassis that can be modularly configured. A melee of skateboard chassis is about to begin.

This article attempts to analyze the latest developments in skateboard chassis from various manufacturers and why everyone has chosen this path.

2. The origin of the skateboard chassis

Figure 1. Schematic diagram of skateboard chassis (from Baidu Image)

What is a skateboard chassis? Simply put, it is to modularize the steering module, brake module, three-electric module, suspension module, etc. installed in the chassis. These modules are connected through the frame, so that the corresponding modules can be changed more conveniently according to the requirements of different models, thereby achieving the purpose of shortening the development cycle. It's just that the chassis, as a whole, is made smoother, which is completely different from the traditional chassis shape, so it is named "skateboard chassis". Fundamentally speaking, it is a branch of the pure electric chassis platform.

So which company first proposed a similar concept? In 2002, General Motors released the AUTOnomy concept car (later named the Hy-wire model), and was awarded the "Coolest Invention Award" by Time Magazine in 2002. This car is a hydrogen energy + wire-controlled chassis model. At that time, it represented General Motors' definition of future cars and brought the public an impact on the realization of future cars.

Figure 2. General Motors concept car Hy-wire (from Microsoft Bing)

Its appearance has two epoch-making significances. First, it applies the wire control system used in aviation technology to automobiles, thereby abandoning the traditional mechanical hydraulic steering, braking and other control mechanisms and switching to electronic signal control. In addition, the integration of hydrogen fuel technology has brought about fundamental changes in the interior space and body appearance of the car. Second, the landing of hydrogen energy in passenger cars is of great significance to environmental protection.

Figure 3. Detailed layout of a generic skateboard chassis (Source: Microsoft Bing)

Without further ado, let's get back to the chassis. The above picture is an introduction to the GM chassis. This chassis is the first to systematically modularize the battery system, control system, thermal management system, and wheel hub motors.

Figure 4. Real shot of a generic skateboard chassis (source: Microsoft Bing)

Since most of the power system's load is evenly distributed between the front and rear ends of the chassis, the vehicle's overall center of gravity is lowered. As a result, the sedan is given better handling performance and can maximize the body height while still ensuring good anti-roll performance, greatly improving the vehicle's overall safety.

Figure 5. Generic skateboard chassis and new body (Source: Microsoft Bing)

General Motors also adopted a new body design, with transparent glass used at the front and rear of the car, giving the driver a wider field of vision. Since there is no engine or transmission system, the cockpit layout is very avant-garde.

Figure 6. Car interior layout (from Microsoft Bing)

The chassis and body are connected by universal interfaces for electrical connection, and the mechanical connection relies on 10 connectors on the body, so as to achieve the requirement of quick disassembly. Although this is a concept car, it also opened the precedent for the subsequent split chassis and body design.

3. Reasons for the rise of skateboard chassis

Just now I mentioned that after the release of this concept car by General Motors in 2002, it caused a strong response in the automotive industry. In fact, the original concept of the skateboard was to use only 8 bolts to fix the body of the car so that it could be lifted and replaced for repair, and even other necessary equipment.

Besides the obvious advantages of replacing traditional engines with electric drive technology and battery packs, the real reason for the development of the platform is the practicality of wire control technology. The maturity of electronic control technology for motors, steering, brakes, and suspension has made it possible to separate these traditional mechanical components from each other, making the platform more flexible and no longer limited to the design range determined by the transmission or steering column.

Figure 7. Transformation of traditional chassis into new energy (from Baidu Image)

Later, Tesla Model S also adopted a skateboard design, and Volkswagen's MEB platform was also developed based on the skateboard technology patents applied for by General Motors. As these patents expired, other skateboard systems also showed explosive growth.

Similar startups focus on developing skateboards as platforms, integrating battery systems, assemblies, and wire control technologies to more flexibly respond to multiple markets. Some companies develop such technologies and license them to OEMs to accelerate the transition from fuel vehicles to pure electric vehicles.

4. Classification and representative players of skateboard chassis

To date, with the increasing maturity of electrification and electronic control, major manufacturers have more or less released various types of skateboard chassis. Although some traditional car companies do not clearly define the platform as a skateboard chassis like start-ups, they are all within the category of skateboard chassis.

There are currently several types of players in the industry: traditional OEMs, car start-ups, and parts suppliers.

4.1. Traditional OEMs

These companies all claim to use electrification platforms or common platforms, and rarely use the term skateboard chassis to describe them. So let's take stock of the products of the leading companies.

Volkswagen MEB platform

I believe everyone is familiar with Volkswagen's MQB platform. Since the launch of the MQB platform, every car feels familiar, and Volkswagen has also enjoyed the advantages of low cost and high efficiency from modular production and assembly, which has enabled Volkswagen to continue to make great strides in recent years.

So what is the MEB platform? Simply put, it is a platform specifically for the production and assembly of electric vehicles launched by Volkswagen Group in response to the growing electric vehicle market. The CEO of Volkswagen Group said that the cumulative production of electric vehicles built on the MEB platform by Volkswagen in the later period will reach 50 million vehicles starting from 2020.

This platform has gradually surfaced with the launch of the pure electric ID.4. This platform covers models from A to D, almost all of Volkswagen's pure electric sedans, SUVs, MPVs and other models.

Figure 8. MEB platform (from Baidu Image)

Compared with the MQB platform for fuel vehicles, this platform removes the front engine and front-wheel drive layout, and puts the battery and motor into the chassis structure. Through the layout of the battery, the front and rear wheel loads are more balanced, and multiple driving modes can be realized. Moreover, in terms of power, all models on this platform are equipped with only one power electronic system, which is highly integrated.

This will significantly reduce costs, mainly in the following aspects:

First, on the manufacturing side, an independent new platform design is used to improve performance and reduce costs. The new energy independent platform does not require an engine, a gearbox, and its transmission system, and the structure is simplified. More batteries can be arranged in the same space, which extends the driving range. In addition, the wheelbase can be lengthened at the same size, which significantly improves the interior space.

Secondly, by modularizing module parts, the production process can be simplified and manufacturing costs can be reduced; by purchasing raw materials on a large scale, procurement costs can be reduced.

Again, in terms of scalability, once the drive mechanism is determined, the vehicle chassis can expand battery capacity, wheelbase, etc. according to the requirements of different models, which can effectively shorten the verification time.

Finally, on the R&D side, by sharing platform technology with suppliers, the R&D cycle and costs can be effectively shortened.

It is reported that Volkswagen will also launch the SSP platform (scalable system platform) and the Sany plan (new architecture, autonomous driving, and new production methods) in the future. The first model of this platform will be unveiled in 2026. Although there is not much information now, it is certain that this may not be as simple as a platform. It may be an innovation of the overall business model in the future. Let us wait and see.

Modern E-GMP Platform

Although Hyundai Motor has had a hard time in recent years, it still invests heavily in new energy vehicles.

In 2020, Hyundai released the E-GMP platform, which is tailor-made for Hyundai's electric vehicles. Based on some shortcomings of electric vehicles in the current market, targeted optimization and upgrades have been made.