Aloha Alex and Dylan. Congratulations on the ‘step’ design while maintaining such strength, durability and light weights. I’ve been riding RS1000, RS1150, and RS1300 for a while now. Prone, sup, tow, wing and RS1300 downwind. Hopefully my RS850-HA arrives real soon! I think, one of the key features of the ‘step’ design is the reduced angle of attack (AOA) of the tip sections (compared to the AOA of the inboard sections of the foil). I believe the ‘step’ provides 2 significant advantages: 1. Reduction of tip vortices (therefore lower induced drag and increased foil efficiency). The ‘step’ helps to redirect transverse flow so water going over the top of the foil is more parallel to water going beneath. The hydrodynamic effect is that of a wing ‘fence’ (Google images of Korean War fighter jets - old Migs and the Sabre - and see some examples). 2. Reduced angle of attack (AOA) of the tip sections of the foil. There a noticeable ‘twist’ at the ‘step’, which results in the AOA of the tip sections of the foil being slightly less aggressive than the inboard sections. I think this ‘twist’ feature is ingenious because it allows a breached tip to re-enter the water more easily. I found that any designs with more aggressive AOA at the tips are more prone to ‘skip’ (like flat stones skip on water - because water is not compressible) instead of slipping neatly back into the water. When your foil tip breaches, you want the tip to be able to re-enter the water cleanly, and not to skip like a stone across the top of the water. A ‘skipping tip’ is bad. Even worse with bigger span foils - because, the longer the span, the more leverage the tip has (to eject the rider). All the very best, JJ
Aloha Alex and Dylan.
Congratulations on the ‘step’ design while maintaining such strength, durability and light weights.
I’ve been riding RS1000, RS1150, and RS1300 for a while now. Prone, sup, tow, wing and RS1300 downwind. Hopefully my RS850-HA arrives real soon!
I think, one of the key features of the ‘step’ design is the reduced angle of attack (AOA) of the tip sections (compared to the AOA of the inboard sections of the foil).
I believe the ‘step’ provides 2 significant advantages:
1. Reduction of tip vortices (therefore lower induced drag and increased foil efficiency). The ‘step’ helps to redirect transverse flow so water going over the top of the foil is more parallel to water going beneath. The hydrodynamic effect is that of a wing ‘fence’ (Google images of Korean War fighter jets - old Migs and the Sabre - and see some examples).
2. Reduced angle of attack (AOA) of the tip sections of the foil. There a noticeable ‘twist’ at the ‘step’, which results in the AOA of the tip sections of the foil being slightly less aggressive than the inboard sections. I think this ‘twist’ feature is ingenious because it allows a breached tip to re-enter the water more easily. I found that any designs with more aggressive AOA at the tips are more prone to ‘skip’ (like flat stones skip on water - because water is not compressible) instead of slipping neatly back into the water. When your foil tip breaches, you want the tip to be able to re-enter the water cleanly, and not to skip like a stone across the top of the water.
A ‘skipping tip’ is bad. Even worse with bigger span foils - because, the longer the span, the more leverage the tip has (to eject the rider).
All the very best,
JJ
Show the wing to the camera?
top . Impatient de tester les RSX!!
🤘