I have a Van R shock on my specialized Pitch
it is 200mm eye to eye.
i have done Tf Tuned spring calc's and based on
Rider weight 85kg - naked so more with kit.
shock stroke 2.25"
wheel travel 6"
Sag at 28% for free ride ish activity.
4 bar linkage with fox shock lists at 524lbs
From this i estimate i need a 550 spring as i most likely weigh in more fully kitted with armour and hydration pack etc.
the current spring lists at 450 x 2.37 but takes up very little of the shock body.
can i fit a longer spring ?
i have included pictures to hopefully better demonstrate this: