Increase in unsprung mass and inertia of the hub, which affects vehicle handling
For ordinary civilian vehicles, relatively lightweight materials such as aluminum alloys are often used to make suspension components to reduce unsprung mass and improve the responsiveness of the suspension. Hub motors, however, happen to increase the unsprung mass and the inertia of the wheel, which can be detrimental to the vehicle's handling performance. But that's not the biggest drawback, considering that electric models are mostly limited to mobility rather than power.
Electric braking performance is limited, and it takes a lot of power to keep the braking system running
Today's conventionally-powered commercial vehicles are already equipped with auxiliary deceleration devices that utilize the principle of eddy-current braking (i.e., resistive braking), such as the electric retarders used in many trucks. Due to the relationship between energy, electric vehicles using electric braking is also preferred, but for hub motor-driven vehicles, due to the hub motor system of electric braking capacity is small, can not meet the requirements of the vehicle braking performance, are required to attach a mechanical braking system, but for the ordinary electric passenger car, no more traditional internal combustion engine-driven vacuum pumps, you need to electric vacuum pumps to provide braking assistance, but also means that there is a Even if regenerative braking recovers some energy, the energy consumed by the braking system is one of the most important factors affecting the range of an electric vehicle if it is to ensure the effectiveness of the braking system.
In addition, hub motors work in harsh environments, facing water, dust, and other aspects of the impact of sealing also have higher requirements, while in the design of hub motors need to be considered separately for heat dissipation.