utcminusfour forum posts in last 60 days

If there is not a tack strap in use, then any distance between the pulleys will increase twist.

This one is for all of us that love to tinker, design, build, test and repeat. He does a great job of explaining foil design.

Grantmac said..
Thoughts on putting a mast track on a higher volume flat rocker wing board?

What wing boards are you looking at? Mast tracks are easy to install and easy to make strong enough. Ps I am watching this one closely because I only have one board ATM and I would rather buy an inexpensive spare today and take my time building a nice board over the winter. The RRD recommendation is interesting, there are none of the bigger ones in stock on this continent that I can find. Here is my current board and the RRD 200. I bet I could have fun with this; the tracks and mast tracks line up with my current design. The foot strap inserts are intended for use with the Tuttle, so for me I would need to add them if I wanted them, I am going to add them to my set up at some point soon.

Hey Grantmac!
Glad to hear you’re getting back into windfoiling! I’m in the same weight class as you, and I’ve been pretty focused on carving freestyle maneuvers for years now. I’m keen to help any way I can.
I agree with thedoor about both the boards and the foils.
The key to learning foiling maneuvers is making lots of attempts. You try, fall in, get back up and do it again. You want a board that is easy to uphaul and helps you get flying again quickly. It’s also a lot less intimidating to put yourself backwinded in 12 knots than in 25, so a board that works well in lighter wind will help your progression.
Swing weight matters, sure, but shortening a board comes at such a cost to takeoff and general comfort that, beyond a certain point, the tradeoff doesn’t make sense to me. I built and tested my own take on what was essentially a Wizard 145, and of all the boards I’ve tried, I liked that one the least. The short waterline was unnecessarily uncomfortable and made uphauling and takeoff harder than they needed to be. I really didn’t notice enough reduction in swing weight to justify those tradeoffs.
I’ve rode the 999 for 2.5 years and really like it. It takes off early, is user-friendly and is still plenty fast. When it comes to learning carving maneuvers, low stall speed is your friend.
Unfortunately, I don’t have a production board I can confidently recommend, and that sucks. There should be more options for bigger riders who want maneuverability without sacrificing easy takeoff and basic usability. That lack of options is a big part of why I build my own boards. As always, I’m happy to share my CAD files if you want to use them as a starting point for a custom.
Of the Slingshots, I agree that the 130 is a better choice than the smaller options, but I’m still not convinced it’s the ideal board for you.

Hey Paducah😀

I’m a big SailGP and America’s Cup fan too. Watching their speeds when maybe I’ll reach 20 something knots someday— its comparing different worlds. I have no need to go much over 20 on a foil board, the impacts from falls are too much for me, but I would like to get upwind better so I can ride more waves. I hope we can get some trickle down!

The Cup boats blow my mind with their upwind VMG. They can sail upwind at close to 40 knots, with VMGs in the mid-20s (source ChatGPT). They have enormous righting moment (but only when foiling🙃) and very low aerodynamic drag. Not to mention a huge wing sail that can be deep and cambered or flat and twisted at the push of a button. The crew is faired in and the bustle on the hull just kissing the water. There has got to be more gains available in windfoil by closing the gap with the water through technique and board shaping. To spawn some creative brainstorming thought, what about something sail like below the board? Maybe its leading edge is a ride height wand, and the sail/end plate extends and retracts into the board with wand motion, think sail fish or tuna dorsal?? Okay maybe that's too creative;) The boards with bustles did not seem to catch on but I still feel like there is low fruit there.

The Moth versus iQ comparison is interesting and more to scale. They carry almost the same sail area—8.25 versus 8.0 square meters—but at recent Moth Worlds the top boats reportedly averaged 22–23 knots upwind and exceeded 36 knots downwind, compared with roughly 18 and 29 knots for the iQ. Those numbers are also from ChatGPT, anybody line those two craft up on the water? Now that the iQ can foil tack it's got to be a closer contest. The iQ might have the advantage in marginal foiling conditions using kinetics, but once both are powered, I reckon the Moth should be faster. I know when I see my buddy coming out in his Wasp (sim to Moth) I go look for some flat water to freestyle in rather than line up with him! It would be cool to compare the aero drag (and total drag) between the two (IQ vs Moth), shrouds, spreaders and racks are speed bumps, but the lower half of the sailor should blend into the rack. And the rack gives them more RM. With the iQ the sailor is completely in the wind. The iQ is a one design from years ago, a brilliant design for its time. We need open design coarse racing to push us forward. PWA foil slalom is great to watch but I want gear that can go upwind.

The one thing ALL the boats are doing that we are not; they use adjustable flaps and or adjustable rudder foils to create stable flight with smaller foils. All of them but the silly IMOCA 60's, I don't get why they have not changed their rules yet but that's a rant for another time/forum.

There isn’t much love for the adjustable foil idea in our community, judging by the negative response the topic usually gets on this forum. I get it, I sail at the beach, sand is a nightmare for fiddley ****, but the performance differences are hard to ignore.