Mini 4WD Wiki
Mini 4WD Wiki

The double rollers (Japanese: 2段ローラー, Nitan Rōrā) are a series of Mini 4WD Grade-Up Parts released by Tamiya since June 20, 2009.

General info

The double rollers, as their names suggests, is a set of rollers with two different, integrate rollers with different diameters, usually 1mm apart.

In Mini 4WD racing, having a set of roller on top of the bottom rollers on the front will improve the car's stability, but this setup was never used because in race regulation revisions prior to the 2019 revision, the number of rollers a Mini 4WD car can have is limited to 6. As most Mini 4WD car setups also needs a dual rollers on the rear, this kind of front roller setup was never used due to regulation constraint. The double rollers workaround this as, despite having two integrated rollers at different diameters, counts as a single roller.

The common setup for the double rollers is to have the small diameter part face upward while the large diameter part face downward. In straight lines, only the large diameter part touches the fences, while the small diameter part is only touches the fences when cornering.

The double roller sets are available in aluminum (with two 520-size ball bearings for each rollers, 2 bushing, 2 long screws, 2 locknuts and 2 brass spacers) and plastic (with two special long screws, 5 to 10 locknuts, 10 to 12 small washers and optionally, 3 pairs of stabilizer balls and 5 spring washers) varieties, and comes in 9-8mm size and 13-12mm size. Some sets even has the rubber rings on the small diameter part.


Parts variants

External link

Tamiya Japan