Ultimate Bushing Package
The Ultimate-series forks also get a new bushing package, with a 53% longer lower bushing, which RockShox says increases overlap and reduces friction by distributing the load over a greater area and helping to mitigate binding when the fork is being heavily loaded. Other fork trims get the standard bushing package, and upgrading to the Ultimate bushings requires an entire UItimate lower leg casting with the bushings pre-installed.
Other Details
RockShox has also added pressure-relief valves, similar to what Fox has offered for a while now, onto all three of the new forks. The valves come standard on Ultimate and Select+ series forks, but can be retrofitted to the other models with the new 2023 chassis versions. The new lowers also get optional bolt-on adapters at the dropouts, which take up the extra space that Torque Cap axle flanges would, to make axle alignment easier if you’re using a wheel without Torque Caps. And to cap it all off, RockShox has also developed a new lower leg lubrication oil in conjunction with Maxima, which they say lasts longer and is more consistent at a wider range of temperatures than their previous lower leg oil.
The base / least-expensive versions of all three forks get a new damper that RockShox calls the Rush RC, with adjustable rebound and compression. We don’t have much info on the Rush RC yet, but have reached out to RockShox and will update this post when we learn more.