Untitled Document

Fork Base Valve Percent [bv%] AND Shock Cadj Percent [ca%]

Shock ca%
ca% = (ca force / c force)
The compression forces are split between the shock mv and cadj piston.
- 'c force' and 'ca force'
The amount of work done by each can be determined by ca%.
The table on the right shows how the 'shock ca% value' is calculated.
- shaft area / (pist area - shaft area)
- In this case ca% calculates to 14.9%.
  - Pressure testing allows us to split the shock compression forces into:
    - how much from the main piston (c force)
    - how much from the cadj piston (ca force)
  - For any given velocity, c force should be about 85% and ca force 15%. This gives a quick snapshot showing if the cadj forces are in the ballpark.
  - [click link for quick example]
Fork bv%
bv% = (bv force / mv force)
- The table on the right shows how 'fork bv% value' is calculated.
- rod area / (pist area -rod area)
- In this case bv% = 14.6% for the YZ 250 and 22.5% for the XCF 350.
Unfortunately, bv% does not work the same as ca%.
- Pressure testing allows us to split the fork compression forces into:
  - how much force from the mv piston (mv force)
  - how much force from the bv piston (bv force)
- Shock ca% will always be around 15% and can be used as a guideline when valving the cadj.
- But bv% cannot be used as a guideline. Long travel and reliance on stiff bv force puts bv% as high as 600%.
- [click link for quick example]