XC-BBKRO-098

RK 219 Oring Chains

According to our field and dyno testing, RK chains and XAM sprockets are the top-performing combination for Rotax Max Senior engines. While most leading brands stretch or break after one day on the dyno, RK chains have shown zero failures and can often last an entire season for club racer. A new chain and sprocket can increase power to the rear wheels by up to 0.75 hp compared to worn components. Even light use (3–4 days) can result in a 0.25 hp loss, so replacement once per event is recommended for national-level racing. O-Ring vs. Non-O-Ring The High RPM Advantage: Although O-ring chains feel tighter when spinning a wheel by hand at low temperatures, they produce more horsepower at high RPMs because the internal lubricant and seals minimize frictional and vibrational losses. For high-horsepower Junior and Senior classes (Rotax, X30, ROK GP), the RK O-ring chain is superior. For low-horsepower Cadet classes, the non-O-ring RK Gold Chain is preferred as it produces more power in low-RPM ranges