Kyosho RFW003-1211 12mm Setting Spring Yellow 64mm

A pair of optional setting springs for the Kyosho Rock Force 2.2 Jimny, measuring 12mm in diameter with 1.1mm wire and a 64mm free length.

At 1.1mm wire these are firmer than the 1.0mm springs supplied in the kit. A stiffer spring holds the chassis higher under its own weight, which preserves ground clearance and stops the truck dragging its belly over ledges and rocks. It also resists body roll, which helps on off-camber sections where a soft setup leans over and walks the truck sideways off the line.

The trade-off is compliance. A stiffer spring makes it harder for each wheel to droop and stay loaded against an obstacle, so on very technical rock the tires can skip rather than conform.

Kyosho sells these as setting springs rather than replacement parts, meaning they exist specifically so you can tune away from the kit baseline. Many drivers run firmer at one end and stock or softer at the other to bias how the truck climbs. Two springs are supplied. This is the 12mm/64mm size, and a softer 0.9mm version is available separately.