@foilholio: great you want to test it ! When I will be skilled enough on foilboard, I will test it on my 15m2 speed2 SA on water.
Indeed diablo principle is ingenious. FYI I also pushed this kind of principle up to its "extrem" with my 19m2 single skin (originally a speed2 19m2) : in addition to Malabar, I have removed B pulley of the kite and connected B bridles knot to A bridles knot. The expected consequence is to increase camber when I am powering the kite and vice-versa (on top of saving the weight of 2*2 pulleys and 2*2m of spare line) and always keep a minimum of stability when depowering. It might be a bit exagerated (relativelly to the initial camber, B will shorten approx 7 cm when depowering which may impact kite performance), but I'll see.
kitexpert wrote:Yes, but more (backline) tension, bigger AoA -> less depower.
Not applicable for Malabar ... rear line tension is doubled but each tension on each bridle (A, B,C, Z) is similar, hence same AoA.
kitexpert wrote:I don't know if there is any difference for depowering whether kite is pulled by line drag or by bar movement.
It is a combination of these two factors: you always have a bit of bar movement consumed by curvature as well as always a residual tension on the rear line due to wind drag. In lower winds, the more you push the bar (i.e. try to reduce AoA) the more curvature becomes dominant on the position of the bar imposed by the rider.
In low wind, when depowering the kite, you visually see the curvature (with a sing value beyond 1 meter horizontal deflection in my experience); and you feel that when pulling the bar you have a kind of increased "elasticity in the bar"; what happened is that that part of your bar pull stroke will be unfortunately used to decrease the curvature and not drive the kite ...(hence part of the stroke is "lost"). At normal wind and speed (say beyond 8 knots) curvature visually seems to become negligible.
kitexpert wrote:If biggest depower is wanted backlines must be quite slack anyway. Shorter and thinner lines allow some more depower than long and thick ones.
We are in line on this (and I even have installed thinner rear lines on my 19m2 for that reason): Malabar or not, lines will be more slack when depowered.
However, at same depower, between standard and Malabar, you will catch more tension transiting in rear lines with Malabar (it is just a transit, no impact on briddle tensions), hence lower AoA because less curvature (i.e. more representative of your command from the bar, which is great).
kitexpert wrote:
"...while Malabar MT also double the rear line tension..." -Regis
It depends. Fully depowered there should not be any difference.
It will still and always be twice tension in rear lines (and bit less in front lines
) . Twice of a lower value I agree, but still twice. I have not experienced the actual impact during a ride, so it is theory for now... up to foilholio next test
kitexpert wrote:When pulling kite to bigger AoA's than with normal system allows, bar pressure may increase drastically, because it does not increase linearly even with normal systems. Backstall of the kite may become limiting factor here.
The initial application is to increase depower (allow a smaller AoA without using the trim strap or clamcleat) rather than increase power (aim is to keep same maximum AoA than with standard bar).
However you can play with it by extensing a bit the front lines and see if a little "over-sheeting-in" with even higher AoA can be useful (depends n kite design, but for jumps needs with skilled riders for exemple or little backstall abilities with can be useful in light wind when controlled. Keep in mind that your strap-trim is still available (and also doubled) to try all those settings and find the one adapted to you and your kite. Depending on kite design, it may require a bit of additional skills if you play with that, since you go beyond kite original AoA variations.
Regarding bar pressure, I don't like bar pressure generally, and I often changed my tubekite models for that specific reason. But I actually used a pulley bar on my previous Aurora 22m during 1,5 year, pressure was significantly increased but I was still able to ride several hours with my little-little muscles (60 kg). I would say it becomes equivalent to a big tubekite with same wind but depends on foilkite design.
kitexpert wrote: Backstall of the kite may become limiting factor here.
as explained above, the malabar is mainly to decrease AoA, not increase it. But if the rider also wnt to increase AoA capacitiers, that is an option, and then it could indeed induce backstall if not properly driven. I would just add that in very light wind (say below 7 knots), backstall is frequent even with standard bar if you pull too much on the bar.
kitexpert wrote:For the biggest of foilkites Malabar seems interesting. For example, if used in Speed21m kite same sheeting range allows more change in AoA than normal speedsystem in Speed6m kite. Malabar system does not change how camber increases when AoA increases.
exactly, fully in line. For example on a 6m2, if the stroke of your arm gives 15 degree variation of AoA, then for a 21m2 kite, you can only command 8 degree Ao0A variation
same
PS: I copy again the Malabar sketch as it disapeared from the topic transfer