Problem fitting longer rear shock FZS600

[joebloggs]

Pre-load does not increase or decrease the length of the shock if there is no other load on it, decreasing the pre-load will soften it and allow it to sag more but at max rebound the shock will still be the same original length.


The length of the shock it entirely dependent on the internal stops.

I get what your saying re the stops etc but is pre-load not the same as a spring compressing over a bump,  when you hit a bump the shock shortens as the wheel rises up the ramp of a bump and then extends on the down slope. pre-load must surely add the same effect if your basically reducing spring length by adding compression (reducing spring length)
With the shock off the bike would this compression not reduce the damper rod length and therefore reduce the distance between the mounting holes.
There are height adjustable car shocks that use preload to alter the length, it's crude but works, looking at videos I see no reason why it should'nt have the same effect on a bike shock absorber. Guess I just need to get the c -spanner out and see what happens