North SONAR SF680Surf Front Wing

Progress faster

The SF-Wings are easy to pump but still manageable to roll from rail to rail. The area-distribution across the span is tuned to the rolling ability of the wing - less area in the tips helps the foil to roll with lower force from side to side. For a foil to roll, it must push the water above it out of the way – less area in the tips requires a lower rolling moment/less force. The moderate anhedral front view combines with a gently swept outline to create a good balance of roll stability, for confidence during pumping and take-offs, and manoeuvrability, for initiating turns with ease.

Effortless pumping

Because it’s so forgiving, you can take out a much smaller surf wing size than you’d expect (for wing surfing). This is appealing if you’re trying to perfect your turns and wave riding. You’re carving with a smaller foil which is more responsive. To maintain such a low pumping speed, we needed to generate more lift out of the foil section at low speeds. We always try to balance lift v drag – so to find that compromise here, we shifted the peak in the lift-to-drag ratio to the lower end of the speed range. Having more profile thickness and curvature in the front section of the profile makes it less sensitive to angle of attack changes.

Composed glide

The SF can be compared to our highly efficient HA Front Wings – only with a much lower speed range. Our Sonar HA Series has a phenomenal glide at medium to high speed – we’ve engineered the same glide into the lower-speed SF-Front Wings. Their aspect ratio ranges from 7.1 (SF1230) to 8.8 (SF930). This can be considered medium-high, however because of the evolved foil section, the stall speed is remarkably low. They can deliver that frictionless sensation of glide at a much lower speed.

Responsive turning

We’ve moved the wing back on the fuselage for a better turning response, so you may need to move the mast further forward in the mast track compared to other North wings. Mounting the front wing closer to the mast reduces your yaw stability, so you can initiate turns more easily.

Match with S215 Stabilizer

With smaller front wings, you want to upgrade to a smaller stab, but it’s important to match the stall speed. The S215 was created with lower stall speed to complement that of the SF front wings. Advanced riders who are seeking a looser feel may choose to remove the wingtips, using the dashed guideline graphic, to create a completely flat stabilizer with a 205cm2 area.