When you are just starting out in foiling, or when you want to progress, it can be difficult to know which foil to choose. Low Aspect, Mid Aspect, High Aspect: what are the differences and which foil to choose according to your level or practice? We explain it all to you.
The Foil has revolutionised board sports. It allows to fly over the swell, to move from one wave to another, partially or totally out of the water. It is accessible to all sizes, all levels, all conditions… Whether it’s a wing, kite, surf or SUP board… Here are all the criteria to consider when deciding between a Low Aspect or High Aspect wing.
WHAT TO CHOOSE BETWEEN LOW ASPECT AND HIGH ASPECT FOIL?
First of all, you should know that the choice of your fin type will depend on your practice and your objectives. Nevertheless, you should consider other factors that influence the speed of the foil: the weight of the rider, the board but also the conditions, the power of the swell… It is important to first understand how a foil works. We have produced an article entirely dedicated to this subject(available in our News&Tutos section), but we will remind you of the essential information.
Like an underwater plane, the Foil moves underwater thanks to its speed and hydrodynamic lift force (upward lift) which lifts the rider onto its support. The Foil consists of a mastIt consists ofa fuselage, a front wing and a back wing (the stabiliser). The wings are more or less parallel to the board, which allows you to act on your foil by simply pressing your feet. The front fin has a domed upper part and a flatter lower part. This difference in shape and profile thickness created lift. The chord is the width of the wing (from the centre of the leading edge to the centre of the trailing edge) and the span is the length (the right/left end) of the wing, similar to the principle used in aviation.
Aspect Ratio Calculation
To calculate our aspect ratios, we use the following formula: span squared/load-bearing area. This formula takes into account chord variations throughout the shape of the wing, as opposed to the often used formula = span/chord. The latter only works if your wing has a rectangle shape and no chord variation. (In other words, it lacks precision).
Lengthening is not everything either. The parameters are almost infinite: angle of the tips, size of the winglets, variation of the relative thickness of the profile all along the leading edge… Each foil is therefore unique. Our philosophy is to start from your needs and offer you a product that perfectly meets them. But also while remaining versatile, rather than forcing the rider to adapt to his equipment. Please feel free to give us feedback and share your experiences on the Sroka Sessions Facebook group. We design these foils for you and to share this passion.