After recording line-pull in all the Beauforts (up to 4+) with my 4 KAP kites I have come up with some line-pull ratios.
Our wind strength forecasts come in knots in Australia so that's what I work on.
The ratios are: line-pull (lb) to wind strength (kn)
7ft Pirate Rok (with flexy fibreglass spars) 1:1
ITW Levitation Delta (normal version) 1:2
Peter Lynn 2m2 Pilot 2:5
PFK Nighthawk 1:3
For example, in 12kn the Rok pulls at 12lb, the Levi pulls at 6lb, the PL pilot pulls at 5lb and the PFK pulls at 4lb.