The Thruster Project

If you're looking to experiment and see how easy it is to convert an existing SingleFin to a Thruster then this section is especially for you.

Kiwi Wavesailing brothers Hans and Nico Wannemacher got into windsurfing 7-yrs ago in Wellington on New Zealand's South Island, and started TheThrusterProject Blog back in 2008. Before MultiFin boards were widely available they were hell-bent on making existing SingleFin shapes turn better which they’ve done with amazing success. Now they only use Thrusters in any type of conditions…and they reckon anyone can make some simple mods without any special tools for instant results!

Objectives

We had older JP and Starboard Acid Single fin boards, and our aim was to make them turn better in the waves. At the time only a few Twins were on the market. We’re still not big fans of those as the fins are mostly too close together – so they’re essentially a modified Single. We set out to design something new and exciting. Naturally we straight away looked at surfboard fins. We modelled the first prototype off an old surfboard I [Hans] had, and decided on Fin Control System (FCS) plugs and fins as they were easily accessible to us and easy to install. Plus they looked nice and the plugs would add minimal weight.

To us, a “Thruster” had to be 3-equal fins and incorporate both fin “Cant” and “Toe” like surfboards. The side fins were quite close to the rails and set pretty far forward, and the back fin was under foot, being able to move the US-box fin to suit style and conditions as usual. The results of the first board just blew us away! The board turned tighter on the bottom turn, and most noticeably on the top turn. There was a major improvement in pointing upwind and the board felt a lot livelier and snappy. There was no real loss in speed, jumping or planing ability. A slightly more upright stance was best and you were able to bank the board more like a surfboard on top turn, so it was sick!

We then made a few more mods to other boards, slightly tweaking fin Cant and Toe-in. We didn’t have the luxury of endless supply of boards of exactly the same specs to truly compare fin combination setups, but the later boards showed that you couldn’t really go wrong too much and virtually anyone could do it! I then went on to modify my starboard acid 66 with two more sets of plug to make a Quad. I went for equal size fins as for me it would only be a modified Twin fin with some SideBites otherwise. Sadly I snapped that board but the bottom turn was similar to the Thruster, but when you banked the board for a top turn it was even more insane than the Thrusters. More fins = more spray. At the end of the day the Quad showed more control and grip, but for the overall package you just can’t beat a Tri.

As far the FCS fins go we tested quite a few. M to L were the best sizes. Glass flex was at the budget end of the range and they provided excellent results when wave riding, but weren’t so good for jumping. Every now and again I’d break a fin landing pushloops as the first fin to hit the water took all the impact and would break sometimes if you landed sideways. Performance core (foam filled) FCS fins rocketed up in price and were also awesome in the waves. But again over time stress fractures appeared in the resin of the base from looping. I stand by glass flex for pure wave-riding  - and my brother’s yet to break one in the waves - but for looping and strength I’ve gone to FCS’s range of Performance Glass fins. They’re made with over 14 layers of glass but have minimal resin so they’re super strong. I’m yet to break one from the constant abuse I give it.

We went through a stage were we had a couple of FCS plugs completely rip out on us. But improved resin/glass installation techniques solved this problem, plus they’re easy repairs anyway. the FCS longboard adaptor to fit a US box wasn’t up to the job forthe centre fins, so we ended-up cutting down and re-shaping standard US box fins. Much better when you hit rocks!

Our other aim is to contribute to the NZ windsurf community through photos and the odd video every now and again. In turn this (and the TP) supports our aim to excite the community and encourage people to try new things and just get on the water.

Gear had got too boring and nothing new and radical was out, so this was another reason why we started the Thruster project. And look at the gear now! Seems like others have had the same idea. We’re still encouraging locals to give a TP a crack on their own boards, but many windsurfers still think too much about gear and conditions. They need to just give it a crack, and this is still our on-going project to show people that Thrusters work well in all conditions and are so easy to install.


So it's Thrusters in any conditions now is it?

Yep. We have no other board types now. That's for down the line wave riding, to cross-on and to onshore wave riding. The Thrusters have shown us they work very well in all conditions.I should probably mention that we're both lightweight riders at 60-70kg, so in a sense our Thruster Project and testing has a slight bias to smaller sailors. Saying that, FCS still has XL sized fins for bigger riders, and it's all down to technique and getting used to the board, like any board really, anyway.

For new wave sailors in over-the-top wind conditions or a monster swell, I'd lean towards a Quad. I recently had the chance to try a Tabou Quad - although a kind of Twin-Quad really if you look at the setup - and it had heaps of control and a mega spray top turn, but that meant less release on jumps too. If newcomers want security in hardcore conditions, I'd pick a Quad.


Do you think Tris need a special shape board or is it OK to just slap-on some sidebites?

Big brands are saying these days that they have designed board shapes to specifically fit Thrusters/Twin/Quad fin setups. I'm not sure how much of this is "marketing hype". I read on a forum somewhere, that after loads of testing with board shapes, that JP found the original wave board shape they had worked best with the Thrusters setup and that new shapes didn't give many advantages. At least they went through the process and I hear now they've got a dedicated shape coming.

Essentially, we're just adding fins to existing shapes that worked much better than a SingleFin product. The shape of the boards we modified varies too. For example, my Starboard Acid 66 has quite a large tail and nose rocker with a double concave bottom between the feet. On the other hand, the JP wave 69 and 75 have flatter/faster rocker on both nose and tail with a more traditional V-bottom shape. All the boards gave the same benefits with the added fins. I think it might also be important to note that we're using boards that are longer than the latest ranges. 245cm approximately. And much narrower too. What's happening to boards these days? They've almost become too short and too wide! I would say shape and outline, rocker and so on is specific to board length, and what style of rider or riding the board's designed for. In my opinion fin setup is minimal.


What's best? Big centre/pretty small side fins or three equal size fins?

In our eyes, a true Thruster has to have even sized fins or three very close in size foils. An equal trio work together nicely and you don't want to upset this balance too much. I'm not a fan at all of a big centre fin and small side fins. I once tried this setup and it just sailed like a dog, the boards didn't sail smoothly at all and the turns were ugly - almost worse than a Single alone. Bigger riders may lean towards a larger centre, for upwind ability or to stop spin out and so on, but it's honestly way better with three larger equal fins. Some changes to your technique and weight on the back foot need to be made to adapt to Thrusters. And a slightly smaller rear 'trailer' fin could be ok if you wanted the board more loose or skatey for fun days or freestyle.


And Toe-in angles?

Yep you just have to have fin Toe, and Cant angles! These allow the board to turn better - like the original surfboard style feel brief. We found moderate fin Cant works well, and fin Toe angles depend on how much speed or more turn control you want. More Toe angle equals more turny.


What do you think about the multipurpose options like Starboard's Quad convertible?

They're a great idea. I honestly look at boards these days and think if I was new to windsurfing I honestly wouldn't have a clue what to buy...how many fins... you could go on! The convertible would let you play around with fin setups either for different conditions or to find a fin setup that you would like.


Have you tested three-fin options for other boards like freeride or flat-water models?

Nope. I no longer own or sail those types of boards. We concentrate on wave boards at the moment. I would expect Thrusters could improve freeride and freestyle upwind ability. Smaller rear fins could be good for freestyle. I do think in high wind slalom though, a larger Single fin would still be better simple because you need that control so you don't spin out easily.


How will someone used to riding Twins or Quads find a Thruster? Are they better suited to people used to Singles?

I've found the Thruster boards behave much more like the Quad I designed, and the Tabou Quad that I tried. I've not tried a Twin but would expect Twin riders to find the Thruster boards easier than SingleFin riders would. Initially when I started riding Thrusters, from Singles, I found them very lively and turny. You have to change your technique quite a bit here and there when riding all multi-fin boards I reckon.


What are they like for jumping?

Thrusters are still just as good as Single fins for jumping. There's no loss in release off the top of waves. Unlike the Quad, I tried; but saying that, this Quad would give and advantage of more control in over-the-top, overpowered conditions though.


Anything else you want to add?

Yeah. A final topic I could throw into the mix is sail combination types that suit different board styles. Just recently, I've changed to the new school compact style [Vandal Riot] sails -- with a shorter luff length. I really like this combination with the Thrusters and my sailing's taken-off. I think the compact design gives just a little more drive with multi-fin boards. Our Gaastra importer in NZ found the same results with his Quad wave boards too.


Special thanks to Hans and Nico. See their guide to installing some sidebites next!

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