Through shaft dampers

[gttouring]

I was reading at Technicalf1.com about dampers and suspension technology...My question (s) lie in damper piston shaft movement, A standard piston in a 'shock' absorber has a finite compression due to the housing and extension limit. Now a through damper seemingly does not have the compression or extension problem because the piston slides clear though the body and the end mounting bracket of the damperbody has a mount in a bridge fashion over the piston (see the page above www.technicalf1.com)
Thus allowing for greater movement. I just do not understand the 'unlimited' movement idea. The piston still has a limit to the compression and extension due to the fact of it haveing not to com apart, as well it is agreed the piston has more movement than a traditional damper, but what stops the movement extremes (silly i know i think i know this one...) and how is it that it is realy a much better set up? The article seems to suggest we are all Shock Engineers and would know this.

[Dave Brand]

Hmm, a lot of speculation & half-understanding there! As I see it, the main advantage of a through shaft damper is that the volume of the damper body is constant irrespective of the position of the piston. The piston area on the 'rod' side is smaller than on the other side, so different volumes of oil are displaced for a given piston movement.

[Onlooker]

that's my understanding of the advantage.I think you get a more constant result and not one that is governed by the change in volume therefore the change in gas pressure.

[gttouring]

ah ha so simple, so the basic set up is maintained without having excessive fluid movement from the 'under piston side' of the shock. So the valves move through their compression or rebound stroke within the damper body and equal fluid is moved, about yes? this leads to as you said more consistant behavior and no limits at either end of the stroke.

[shiny side up!]

I think you've hit the nail on the head here, basically it is more consistent over its entire operating range.