AR Chassis
The AR Chassis (ARシャーシ) is a Mini 4WD chassis released by Tamiya in 2012. It was first seen with the release of Aero Avante.
It has the same long wheel-base as the Super-TZ Chassis has. Because of this most premium version of the early minicars with Super-TZ Chassis has been using AR Chassis.
Unlike most of the chassis, it features the aero-dynamic designs all over the chassis, and batteries and motor can easily swap out by remove the under chassis parts, providing much more simple maintenance compare to the other chassis.
The underbody of the chassis is curved and flat with the rear motor cover and roller stays acts as diffusers, allows smooth air-flows under the car.There's also several air-ducts that are made to dissipates heats from the batteries and motor while running. (However, the air-ducts placed on the top of the chassis is only useful while using bodyshells from Mini 4WD Rev series cars.)
The front bumper and rear roller stays has been extended to provide smooth cornering and there's muitiple screw holes to provide better parts attachments. The rear roller stays are not removable by design, and there's the brake skid bar attached under them.
Unlike the previous chassis, the secondary parts (including rollers and bearing) were molded in the low-friction POM plastic and this eliminates the brass bearing parts all together.
The battery switch is the curve-slide-type, and due to how it design the car is unlikely to turn itself off while running.
Performance-wise, it performs better than any rear-motor shaft-driven Mini 4WD chassis to date, however due to its weight, its cornering and acceleration performances is a little inferior than that of Super-II Chassis. Even so, Super-II Chassis has poor stability due to weaker chassis structure and the lacks of aero-dynamic design underneath the chassis.
The AR Chassis is the second heaviest chassis, following the newest MA Chassis.
It should be note that not all bodyshells made for Super-TZ Chassis are completely compatible with AR Chassis. (Tiger Zap is the main example of this due to its bodyshell design) Some bodyshells comes with the front bumpers attachment that are not compatible with AR Chassis. (i.e.Thunder Boomerang)
In the official Mini 4WD regulation, the uses of normal and purple pinion gears for the motor in AR Chassis are strictly prohibited, and requires the use of either carbon pinion gear (comes from either the stock AR Chassis car kit or the Grade-Up Parts) or brass pinion gear. This is because normal and purple pinion gears are no longer able to withstands the stress the chassis has put them into and will eventually breaks.