Tech Notes: RPM A-arms for the ARRMA Kraton 8S & Outcast 8S are sold as one upper and one lower in each kit. One left (#81522) & one right (#81562) will be needed to complete the front end of one vehicle. RPM A-arms replace the upper A-arms from stock ARRMA #ARA330561 and the lower A-arms from stock #ARA330589.
Installation Notes:: Like stock A-arms, RPM Kraton 8S versions are sold without threads. If the pivot ball hole is difficult to thread using the pivot ball, RPM recommends thread tapping (tap not included) the hole for 3 – 4 threads, but do not tap any further. Additional cut threads will negate the thread-locking capability of our materials.
The ARRMA Kraton 8S & Outcast 8S are 26 lbs. (12kg.) of high-flying, dirt shredding, jump-killing fun! If your A-arms aren’t up to the abuse these massive monsters can dish out, look no further than RPM. Our replacement front A-arms are designed with the backyard basher in mind and can handle some serious abuse and come back for more.
Our front lower A-arms have a triple beam style construction designed to spread impact energy across all three beams. Each beam’s cross-section is a whopping 5/8” (15.8mm) tall x 3/8” (9.5mm) wide. These massive beams reduce unwanted flex during normal suspension movement, yet allow impact-absorption during those not-so-perfect landings and crashes. We also moved the inner cross brace away from the chassis, eliminating the droop stop entirely. While this may seem counter-intuitive, our test truck’s chassis was bent at the droop stops, clearly illustrating that extreme impacts were too much for the chassis plate to handle. After all, there’s not much worse than a bent chassis.
Our front upper A-arms use a dual beam construction where each beam is a massive 1/2″ (12.7mm) tall x 3/8” (9.5mm) wide. We eliminated the tube shape over the hinge pin to eliminate built-in molding stresses while beefing up the leading edge hinge pin support to add some much needed strength and durability.
Both upper and lower A-arms are molded with fingernail slots that allow easy access to remove the aluminum support ring (not included) at the pivot ball. Made in the USA from our trademark blend of ultra durable materials, you can’t go wrong with RPM!