605-01-108 rev
B
Pg. 7
READING THE SPRING RATE
FOX coil-over shocks only use quality, high stress race springs. The springs are a shot-peened, heat-treated
chrome-silicon material, designed to give maximum travel and minimum weight. They are preset to ensure
they don’t sag over time.
TIP: The springs are typically labeled: XXXX-
XXX-XXXX
For example: 1000-250-0225
The first four digits indicate the spring free length: 1000 = 10.00 inches
The middle three digits indicate the spring free internal diameter: 250 = 2.50 inches The last four digits
indicate the spring rate: 0225 = 225 lb-in
SETTING THE RIDE HEIGHT
All FOX coil-over piggyback shocks feature adjustable spring preload. Your vehicle performance is sensitive
to ride height variations.
P/N 398-00-393
WARNING: Do not add excessive amounts of preload into the coil spring. Doing so may result in coil-bind,
which could lead to spring failure and potential injury or death. To check coil-bind, put several zip-ties around
individual coils. If they break or show contact, there is excessive preload. If you are at maximum preload and
need more ride height, contact FOX for a stiffer spring.
