Herman wrote: ↑Thu Jun 06, 2019 9:17 am
Hi sergie! When thinking of turning moments applied to static riding you may find it helpful to analyse it around the centre of lateral resistance of the board, ie. the board is not a foil or wing, particularly true for flat twin tips. The force applied to the board is a what goes through the feet, a combination of mg and kite pull. More force on the aft foot will create a greater turning moment into wind. Carving turns involve a different set of forces.
Lateral resistance for tt.: Hold it in water in ridden position, push on nose it bears away, push on tail it hardens up!
Thanks Herman!
IMHO "more push on the front foot" ="move center of mass forward". For example if a human had a shape of a ball and did not have legs he would roll to the front of the board and board would go downwind. Having 2 legs is just a convenience
In physics they say that body turns when force (or better sum of all forces) applied does not go through the center of mass. IMHO what we do is we move center of mass. If we were lying on the board we would need to crawl front.
I totally agree to your way of explaining it though. Your explanation is equivalent to moving centre of mass forward, just has more details in it as to how to do it, thanks.
And I do not quit agree with Matteo here that it does not apply to planing. Laws of physics do not change.
My latest greatest idea is that while planing moving weight also moves centre of pressure in the same direction (angle of attack is smaller when we load front).
The move of centre of pressure I imagining might just make moving center of mass to be a less efficient method while planing. I mean move center if mass forward -20cm might cause move of the center of pressure forward by say 16cm, so not much change in turning moments happens.
This is if Matteo is right about loading front or back not being main way of turning TT while planing. I do not have enough experience but his windsurfing example is really convincing!