Jerome Bonieux - Behind The Design of the Daytona DOS D/LAB

Welcome to behind the design of Duotone Kiteboarding! Today we are catching up with Jerome Bonieux to talk about the new DAYTONA DOS D/LAB FOIL. Hailing from the idyllic island of Mauritius, Jerome was the designer and inventor of the CLICK BAR and currently heads up the racing equipment program for the Duotone foil division. We catch up with him to get some insight into the new second edition of the Daytona foil, the Daytona Dos D/LAB in the lead up to the 2024 Olympic games.

Hear the Full Interview

Hear the Full Interview

Hi Jerome and welcome, please take us through the design and developments of the new Daytona Dos.

With the first edition of the Daytona we knew we had a very good foil, still on the racecourse we knew it wasn't as fast as some of our competitors, so with the Daytona Dos and this foil being targeted for the Olympics, we really wanted to make sure it was faster and not just in straight line speed.

We had a lot of things from the initial Daytona that we were very happy about, first of all the construction and we were very happy with our manufacturer. We knew we would have to move to high modulus fibre to keep the same rigidity we had with the initial Daytona, but decrease the thickness. The mast is now thinner on the Daytona Dos and also the fuselage is thinner, anywhere we could go thinner, we did it and used the High Modulus to compensate for the thinner cross sections.

We worked on some new profiles for the front wing and the stabiliser and did many rounds of simulation on the software. We settled for a profile that looked really good.I'm looking forward to explore all the avenues that we have found with the research of profiles. I think the next few years will bring us very interesting results, we have found some very fast profiles and a very powerful upwind performance that is able to go deep and fast on your downwind tacks.

How does it feel to ride the Daytona Dos?
If I had to describe the Daytona Dos in one word it would be ‘precise’. The response from the input of your legs is really direct and that comes first of all from the rigidity of the whole assembly, but also the foil has a very responsive feel. You point it in a direction and it’s instantaneous. That’s something I really like, it gives you a really engaged feeling with your foil and you are able to place it wherever you want. So if you're going through chop and you are having to manoeuvre a little bit up-and-down, with just a small movement of the front, the foil follows where you want it to go. It's also easy to go downwind on a very deep angle, you can just keep pointing it deeper and deeper and the foil has no problem going for that really deep down wind trajectory, which is super important for race foils because the angles the guys are doing now are mind blowing.In the tacs I really like this foil, because it's so precise, let's say you are following a guy and he's about to tack in front of you and you have to do a super quick tack, it’s super reactive to any input you give it and you might be able to overtake.This does mean I would recommend the Daytona Dos for advanced users, because someone intermediate might be having some issues with the fact it goes so fast! Once you put a bit of power through the board, the thing just wants to go. Any advanced rider that is comfortable doing tacks and gybes is going to have a lot of fun on this foil.I specifically like it in light wind, but it works very well in strong winds as well. Myself, I’m a light rider, I tend to perform better in light wind conditions, most of my riding hours are spent in light wind, but we still achieved speeds of forty plus knots in strong breezes.

The Daytona Dos is really direct, really engaged, the drag from the foil is very low. I’m really looking forward to seeing the first riders to use it in competitions and seeing how we do against all the other big names. We are planning to ship some foils to some key riders, so it won't be too long until we know what kind of results the boys and girls can get out of the Daytona Dos.

Let's talk a little bit about Ixent, you had the opportunity to work with the America's Cup winning team of design engineers in development of the Dayton Dos, how was that experience?

It has been amazing to work with Ixent, we are learning a lot, every single project we do we are learning a lot from them and at the same time they are learning from the project.

They know a whole lot about layups, profiles and structures, but there are things that are specific to hydrofoil kiteboarding that they rely on us, the rider and the designer, to give them some specific information. It’s been a super positive experience to work with them

What insights did they bring from the sailing world?
First of all, the profiles. They worked to create a really fast mast profile that would resist ventilation and at the same time allow us to keep a good structure and keep stiffness in the mast. For example you could choose a super thin mast profile, which would have a very low drag coefficient, but then your mast would be very soft and flexible. Finding that perfect compromise between structural integrity of the mast and making sure it's fast and doesn't ventilate is key.

It's a very similar case for the front wing and the stabiliser; again picking the right profile and making sure the structure will be fine. There are lots of high stress points on the gliders so having the right lay up is crucial, that’s where their experience came in. With the first edition of our Daytona and now the Daytona Dos we haven’t had a single case of failure, so that makes us confident that this foil is strong, this is the kind of thing the professionals at Ixent can bring to us.

The most important thing is we are still learning from every project and also from other foil companies. We cross analyse the theoretical results with actual on the water testing and then we are able to better fine tune our calculations. It's really exciting to know that every single project we start, we have a better understanding of where we should be heading, it’s just very exciting for the future.

Let’s talk about the Olympic committee and the I.K.A. They have a box role in place for all foil designs registered for the Olympics, how much did that restrict what you wanted to do with the design?

Yes there is a box rule, so you are limited for example to your mast not being shorter than a certain length or longer than a certain length, they set width limits and the same for the fuselage. So you are contained in a box, but I have to say they were not really limiting, there was not one parameter that was a problem for us, so I think the box rule was fairly loose. The thing that is probably harder to meet, is the manufacturing tolerances.

Every single foil we produce has to be identical, we’re talking tenths of millimetres in profile thicknesses from one foil to another, you can only be 1/10th of mm away, if you are looking at the cross section of the foil for example.

This is something that is fairly difficult to do, you need a manufacturer that is really precise, luckily we have that and we were able to pass that requirement. Every single foil has to be measured using a special jig built for your foil. The glider for example is bolted to that special jig, which has specific points where you can come with your calliper and do really precise measurements. Everything is recorded, if any of these measurements are off, you can’t put the IKA sticker on it. So this was probably the hardest perimeter to meet.

Did you have multiple riders testing the new Daytona Dos and did the Covid-19 pandemic affect the testing process?
It's mainly been myself doing all the testing for this foil, so currently we don’t have an official hydrofoil race team at Duotone, so given the time we had, we didn’t have a lot of time to send parts all around the world, it was quicker to send them to me for feedback. I have a few friends who are really good local riders, so we are able to share feedback on the water swapping from board to board. We compared the Daytona Dos against the old Daytona and against other brands. We did all the development by shipping the prototypes directly to me for fine tuning.

For sure Covid-19 has been a big impact on the development, first of all the factory delays, they had to close the factory for weeks, then there were delays in deliveries due to limited flights arriving into Mauritius. So it's been quite painful, it also meant we could only do so many rounds of prototypes, and of course I would have liked to be able to do more rounds of prototypes, but I am still very happy with the end result. It's unfortunate we had the pandemic in the middle of the registration period, that was not ideal, but it was the same for everyone I guess!

Thanks for your time Jerome, we look forward to see how it performs in the next few races!
Thanks for taking the time to get this info from me and the team, let's keep in touch and reflect back once we get the first results from the team!

#TEAMTALK with Jerome Bonieux - Duotone Daytona DOS D/LAB