AR Chassis

The **AR Chassis** (Japanese: ARシャーシ, *Ēāru Shāshi*) is a Mini 4WD chassis released by Tamiya in July 2012. It was first seen with the release of Aero Avante. The 'AR' stands for 'Aero Racing'.

## General info

The AR Chassis shares the same wheelbase with the Super TZ Chassis.

Unlike earlier chassis, the AR Chassis is designed with aerodynamic performance in mind, sporting a more streamlined silhouette to promote better airflow and less wind resistance through the rear motor cover and roller stays which act as diffusers. There are also air ducts for better heat dissipation for both the batteries and motor, though only those bodyshells that were specifically designed for the AR Chassis, e.g. those from the Mini 4WD REV line, can take advantage of this. Another selling point with the AR Chassis is the battery tray and motor mounting mechanism located in the undercarriage, which can be accessed by removing the battery and motor covers. This allows for easier maintenance compared to most other chassis.

The front bumper and rear roller stays has been extended to provide smoother 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 moulded in the low-friction POM (Polyoxymethylene) plastic and this eliminates the brass bearing eyelets from the bearings all together. Due to how rigid the chassis was designed, it is stronger than any single-shaft-motor-driven chassis to date.

The battery switch is the curve-slide-type, and is designed to decrease the likelihood of turning itself off while running. It also serves as the locking mechanism for the battery panel, as it prevents the under panel from detaching itself from the chassis while running.

Performance-wise, it performs better than any rear-motor shaft-driven Mini 4WD chassis to date, however due to its weight and long wheelbase, its cornering and acceleration performance is a little inferior than that of short wheelbase chassis such as Super-II Chassis and later VZ Chassis.

## Colors

### Chassis frame

* Black - Common color for all new minicars. First equipped with Aero Avante.
* Metallic gray - Common color for the Premium variant of the old minicars in the Fully Cowled Mini 4WD series. First equipped with Aero Avante Red Special.
* Silver - First equipped with Aero Thunder Shot Japan Cup 2013 Limited.
* Magenta - First equipped with Aero Manta Ray White Special.
* Smoke - First equipped with Shadow Shark Yellow Special.
* White - First equipped with Slash Reaper Clear Red Special.
* Dark blue - First equipped with Aero Manta Ray Japan Cup 2014 Limited.
* Red - First equipped with Aero Thunder Shot Black Special.
* Orange - First equipped with Beat-Magnum AR-14 Turquoise Special.

### A parts

* Black - Common color for all new minicars. First equipped with Aero Avante.
* Red - First Equipped with Aero Avante Red Special.
* Blue - Common color for the Premium variant of the older Magnum cars. First equipped with Cyclone Magnum Premium.
* Orange - First equipped with Aero Thunder Shot Japan Cup 2013 Limited.
* Light gray - First equipped with Slash Reaper Clear Red Special.
* Light pink - First equipped with Aero Manta Ray White Special.
* German gray - First equipped with Aero Manta Ray Japan Cup 2014 Limited.
* Purple - First equipped with Aero Avante Violet Special.
* Gray - First equipped with Diospada Premium.
* Yellow - First equipped with Shadow Shark Yellow Special.
* White - First equipped with Shadow Shark Italia Special.
* Fluorescent orange - First equipped with Beat-Magnum AR-14 Turquoise Special.

## Trivia

* For the first release of the AR Chassis (Aero Avante), the first mold of the chassis had a problem with the rear side of the chassis constantly contacting the inner part of the narrow rear small-diameter wheels, which results in power loss. This was fixed with the second mold revision which was included starting with Aero Thunder Shot.
* In the official Mini 4WD regulation, the use 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 break.
* It is the second heaviest chassis to date, following the newest MA Chassis.
* The AR Chassis is compatible with bodyshells made for Super TZ and Super TZ-X Chassis. As such, most premium version releases of the early minicars with Super-TZ Chassis use the AR Chassis.
	+ In addition to Super TZ Chassis bodyshells, bodyshells intended for the Truckin' and Wild Mini 4WD series can be used with AR Chassis using the Side Body Catch Parts. Incidentally, the Premium releases of the Truckin' cars used AR Chassis and include the catch parts.
	+ It should be note that not all bodyshells are completely compatible with AR Chassis. (Tiger Zap is one such example due to its bodyshell design) Some bodyshells come with the front bumper attachments that are not compatible with AR Chassis, such as Thunder Boomerang.

## References

1. ↑ Mini 4WD Grade-Up Parts Matching List (Gear sets) (Japanese)