"The wings provide the lift"is a half-truth often heard among foilers. On closer inspection, this statement is not true, because lift is actually only generated by the front wing. The stabiliser, also known as the backwing, actually generates downforce.
Klaas Voget and designer Jerome Bonieux from manufacturer Duotone explain why this is the case and what adjustments you can make when tuning your own grand piano in these two episodes of their Tech Talks.
Part 1: Foil Basics
Part 2: Foil tuning - position, trim and shims
If you are interested in more Tech Talks, you should definitely check out the YouTube channel from Duotone check, there are more topics here.