Dec. 17, 2016, 11:18 a.m. -  Steve Mathews

#!markdown There are actually 3 generations of the RC4, at least the way we break it down. The first gen (5/8″ shaft and Boost Valve) which had some issues with the forged eyelet cracking around the HSC/LSC adjusters, the second gen (same thing but fixed that breakage issue), then the third gen which had the 1/2″ shaft. The 1/2″ shaft variant was a bit of a hackjob to be honest - it had better rebound control but the oversize reservoir which was necessary for the 5/8″ shaft became redundant, you lost the ability to control ending stroke ramp up (the "air assist" thing didn't do a whole lot - it was just left there so they didn't have to change any parts) and they went back to the 1/2″ shafts which occasionally cracked at the eyelet threads. This was basically Fox copying what backyard mechanics had been doing using DHX parts (the shaft assembly and seal head) and removing the boost valve. The 2nd gen ones were the most bulletproof and a great performing shock, but a bit confusing to set up. The 3rd gen ones were a little easier to set up because they weren't very sensitive to air pressure and the air assist thing was pretty useless, so it cut the number of actual adjustments down a bit.