Can I retrofit the Ultimate bushing package on RockShox Select + and Select forks? The bushings are sized and installed into the lower leg at the factory. The only way to upgrade the bushing package is to install the MY23 Ultimate lower leg. Related articles Are there differences in RockShox lower legs between Ultimate and Select+? What’s different in the Ultimate level bushing package? How does it benefit my ride experience? Can I upgrade my current RockShox fork to Pressure Relief Valves (PRVs)? Can I upgrade my current RockShox fork with a DebonAir+ airspring? Will my RockShox fork lose oil through the Pressure Relief Valve (PRV) while transporting my bike?