This morning I got back from an open water swim with my son and this email was waiting.
Popdart dims based on our discussion looking like 7′ x 27.5 x 3.875 x 86L. We can bump up volume by either tweaking width or thickness (or length). My recommendation would be to keep it thin and go a tad wider. This thing will be a rocket ship.
TVD dims are similar — 7′ x 27.5 x 3.875 and 86L. Again, a width/thickness/length tweak will increase volume if you’d like to hit 88L mark.
This is the PD CAD model.
I love the look! I know that Kieth commented yesterday that look isn’t everything and I agree, but there is an aesthetic element to a good surfboard design. There are some boards that you can look at and know they’ll be dogs.
Some initial thoughts on this Popdart. Kirk says it would be better to say wide and thin, but my reaction is that I could still paddle it just fine at 26.5 and that might make it surf better in the pocket. Something I’m really looking forward to testing is how a 4 inch plus surfboard works when you thin out the rails and keep the volume in the middle, that’s what Pat Rawson has been shaping Mo. I wanted to try his boards when he was here, but I could’t paddle low 70’s volume.
I’m going to ask Kirk for a center rail section of this shape to see the rail profile. (Kirk sent it)
Keith also asked about hull designs. Kirk, can you comment here and shed some light on different bottom contours and when/why you use them? This board has some significant channels. What’s that going to feel like?
I’d love to see what a 6.10 at 26.5 would look like. How thick would it need to be to hit 85L?
From Kirk –
Erik, reducing length to 6’10 would mean an increase in thickness to 4.125″ to net 85L. Only a .25″ change. And you’re right – narrow always surfs better. The tradeoff can be adding thickness which affects how high up the board sits in the water thus affecting overall stability. However we are splitting hairs here. ? I also sent you a section through mid to show how the volume is distributed and the step rail design. The Popdart incorporates a single concave running entry to just behind middle. Then transitioning into a double with Vee and the channel bottom. The concave bottom design adds more rocker at the rail than through centerline. More rail rocker translates to tighter turns. The theory behind the channels to add more grip to the rather significant waterway between the fins. From personal experience with these wide tails, the channels make the boards really drive through turns while adding another level of control to all the speed these things generate.
I typically run the displacement hull entry in the classic SIMSUP shapes as these boards are designed to get on plane easy and early and go fast. The hull “belly” up front parts the water generating lift and allowing the boards to fly. I’ve built Popdarts with hulled entries too but personally prefer the single concave.
Today starts the Designing a Board series with Kirk McGinty from L41 Surfcraft. Part 1, today’s installment, is our opening conversation about design and the current L41 models. Over the next week Kirk will be sending me some ideas hitting my target dimensions, which I’ll be sharing with you all, and then we’ll decide and build one of the boards. It will be my board for our upcoming California trip, I’ll journal on the ride and then Kirk will come back on the show and we’ll discuss the process and performance.
Kirk isn’t your normal shaper. He’s an industrial designer at Google. He spends his days designing and building state of the art technology and in his free time he designs and builds surfboards. He’s just the guy I’d like helping solve for the future of paddle surfing.
We discuss a few different models of his boards on the show. Here are a few so you have an idea of what we’re talking about:
The Original SIMSUP
The TV Dinner
In our first discussion we’ve agreed that we don’t want to shape a board similar to what I normally ride. This is an experiment in performance for me, and Kirk thinks it’s going to blow my mind to surf a sub 7 foot board.
I’m leaning towards the Popdart or the TV Dinner, as I still do want some aspects of performance. I’ve ridden enough Simmons surfboards to have a general understanding of their strengths and weaknesses, what I don’t know is how the paddle will change that.
For dimensions, I’m going to opt for a bit more foam than normal. There are a few reasons.
1. I’m going to be using the board for the first month in California. I haven’t put on a wetsuit in 10 years, but if I remember correctly they’ll add a few pounds.
2. We have a lot of small, clean, mellow days where I live, and I’d like a cruisy board for those conditions.
I want to go as short as possible. If we can come in at 6.8 or around there I’d be stoked. Width will likely be 27-28. I’ve been on the trend of narrower is better, but I had some magic sessions on my Starboard Airborn, my first small SUP, and that was 28.5.
Check back in a few days to see the first designs that Kirk’s come up with.