Originally developed for endurance racing teams, the RV6 CTR helical 4th gear is finally available to the public. Bottom line: it has survived the rigors of endurance racing, it will almost certainly handle whatever you throw at it. RV6 spent the last 3 years testing and refining to arrive at a product that can take serious abuse. These gears feature a strong helical profile with increased contact area. Lower tooth count and larger teeth allow the gears to handle more torque and shock load.
As you know, 4th gear is the weak link in the FK8’s transmission. It is usually the first failure point in high power applications.