Foil Drive Help: Three-Blade Hub & Propeller Bolts
The Three-Blade Hub is a direct replacement for the standard two-blade hub and fits all Foil Drive systems except the original Assist. Current hubs come with CNC-machined 316 stainless steel propeller bolts. They're stronger than the original bolts and have a shoulder under the head that must seat fully into the propeller mounting hole. Don't substitute other bolts unless Foil Drive has approved them.
Installing the propellers
- Inspect the hub. Mounting points should be clean, and the threaded inserts should sit flush with the hub surface with no sand, salt or damage. If an insert has pulled out of position, don't fit the prop until it's been reseated.
- Fit each propeller flat against the hub, the right way round, so it can fold freely.
- Install the bolt through the prop into the insert so the shoulder locates in the hole. Tighten until the head and shoulder are seated, but don't overtighten. The blade must still fold in and out without binding.
- Repeat for all three blades.
Check blade movement (the important bit)
With the motor off, fold each blade through its range. All three should fold in and flick back out freely and evenly. A sticking blade can release suddenly with a lot of force when the motor starts, causing vibration and putting extra load on the prop hardware. If a blade sticks: check the bolt isn't overtightened and back it off slightly, check the insert is flush, look for moulding ridges, debris or salt, and rinse the hub with fresh water. Don't ride with a sticking blade.
Saltwater care to avoid breakages
The new bolts have a smooth shaft and shoulder instead of a partly threaded shaft, which makes a stronger, stiffer mount. They come with a little thread-retaining compound to stop them loosening (it isn't meant to lock them permanently). Because the smooth shaft doesn't let saltwater flush out as easily, salt crystals can build up around the bolt over time. If a prop starts to feel stiff, grabby or hard to fold, remove the bolt, rinse the hub and prop thoroughly with fresh water, clear any salt or debris, refit the bolt and check movement again. Rinse regularly with fresh water, especially after saltwater sessions.
Before every session
- All three bolts secure, with no heads protruding.
- All three blades move freely and deploy evenly.
- Inserts seated correctly, with no sand, salt or debris.
- No visible damage to the hub or props.
If a prop sticks, the hub is damaged, an insert has moved or a bolt won't seat properly, don't use the system until it's sorted.
Questions? Call or email The Foil Shop. Call (909) 326-0732, email info@foilshop.com or contact us here and we'll help you sort it out.