The piston doesn't displace oil, the shaft does. A big piston potentially flows more oil, putting those shims/valves more in control of the damping, rather than the size of the passages being a limiting factor for high speed events. But a bigger shaft is what moves more oil into the reservoir and gives the resi valves more authority over the damping.
Nov. 9, 2022, 5:18 p.m. - Justin White
The piston doesn't displace oil, the shaft does. A big piston potentially flows more oil, putting those shims/valves more in control of the damping, rather than the size of the passages being a limiting factor for high speed events. But a bigger shaft is what moves more oil into the reservoir and gives the resi valves more authority over the damping.