This is a very interesting question as downwind is the opposite of upwind.
This question is very exciting as you can have the 'theory' and the practice.
Theory says that max speed need high AR kite (high AR kite gives less drag and need less time to pass from zero speed to max speed).
But, for speed records in kitesurf for the last 10years, the angle from wind is around 130-140° in 35-50knots of wind, then to have power for such angle, you have 2 ways:
- Having a high AR kite. Using such kite needs to have a larger kite than a medium AR because the kite go more forward in the wind window, then create less power. Rod douglas use a high AR kite and use the largest kite in any contest compare to others. This is due to his power and the AR of the kite.
- Having a medium AR induces the kite deeper in the wind window: deeper in the wind window = more power, then smaller kite. This is the choice of some riders: Caizergues, Salerno.
Then, the choice for the present days depends on the riders.
But in the next year, I can assume that we will go for high AR.
When you see the performance of VESTAS boat, the choice is clear. In the future, the target is to beat records in less wind. For that, we need more performant kites, and more performant boards with less drag.
Performance = more efficiency.
See you in 5years
5 years ago, kites haven't any bridles, then wait and see!