Who's this bloke that claims thrusters are crap?
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Everyone's entitled to their opinions.
Speed sailors in flat water might favor singles.
Bump sailors in waves, often underpowered, might favor tris.
Best set-up is ..... TO KEEP AN OPEN MIND ... all way through your windsurfing years ...
Remember - Pro's get maybe more 'stuck in their ways ' with equipment set-ups , and rightly so ... as they have the added pressure of contest consistancy to worry about - sometimes Its not worth it for them to mix things up too much or confuse matters with moves - as flicking between set-ups makes a big difference to helping / not helping ...certain wave trick scoring moves ... and you have to change and adapt your style (again - not always best for contest performance)
No 1 set-up reigns supreme .... all set-ups have their 'Pro' level followers ... braw & campello quad for example , KT / traversa/ Juban / Antoine / Ezzy / Stone thruster ... , mainly Koster for twin , and some like Levi Siver - flick between quad and thruster non stop ...
For recreational windsurfers / weekend warriors - change things up a bit if your getting a bit jaded on the water / sensations the same ... If you want to land new moves - sometimes changing fin set style helps dramatically ... The only barometer is if your steadily improving ,... if you are - you are probably keeping an open mind - and open to trying different set-ups to accomplish different things , and using set-up strengths and weaknesses to your advantage ... And sometimes its a game changer for yr sailing getting forced outside of your normal set-up comfort - to adapt and learn new styles of sailing ... I for sure had to switching quad to thruster .
I sail alot of side / side off ... and still swap back and forth between quad and thruster ... both have their + and - ..... Lately Ive also thought about jumping back on twins for certain smaller mushier conditions sideshore as they're so nice and forgiving for trick moves on the wave ... (ie higher consistancy landing moves)
For guys running quads as twins in mushy conditions:
How do you select a fin size/template and where do you position it compared to sailing as a quad?
I'm tempted to try my Quatro as a twin. The stock front fins are already on the smaller size but its rear boxes have very limited adjustment. It seems to prefer rears with a more upright template as a quad.
I run 17.5 cm BP fins. Side fins you see in the pic 9cm almost never hit the water as most of the time it's onshore wind and I use the board as twin. Not sure what spinout you guys are talking about for twins.
I remember I had Mistral Twinzer 84 and now Quatro 95 and never experienced any spinouts. I can stall them if I point too far upwind, yes, but spinout...don't remember a single time. I think that in 84 I ran ether 16 or 17cm MUFs XTwin. I also have no idea why people say you cannot drive twins hard. Also landing is nicer. Single can start sliding if you screw up the landing. Twin holds so much better..
Never used thrusters much.. Either single or twin.
I generally run 9f/15 or 16 rear. I have some 17 Scorchers but they are quite swept, lots of area at the base though.
Usually if its quite strong I'm stepped down to a board which runs well as a thruster.
Hmm. Another problem with trusters nobody wants to talk about is that you need to screw in 3 fins instead of 2. LOL Often even 4 if you need to switch from a single. Twin, just one pair of fins for all conditions. Set it and forget it ..
I have a custom tri-fin and two quad SSD boards. My experience is mostly with quads and twin fins. Including fin positioning, fin sizes, fin style, fin profiles, fin foils (e.g. asymmetrical), fin angles in relation to center line. However, nowhere near the number of fins and amount tweaking some of you do .
Found a number of factors that can be more (or less) important such as:
1. Board size
2. Board shape, especially tail outline, V and kick
3. Conditions such as wind strength, sea state, wave size/type, wind direction and tide/current
4. Weight of rider (I'm a welterweight)
5. Fin tuning and sizing
I love my old tri-fin board. It's probably hard to compare your or manufactures setups as it uses 120mm surf fin side biters that have approx 80/20 foil shape. Surfers reviewing these say that they turn significantly quicker and smoother than flat inside foil ones. I would say this trait holds true overall for this board compared to other boards that I have tried or owned. The feel is closer to my surfboard especially taking off down the wave.
The side fin boxes have 1.2 degrees of toe-in. My relative spacing is closer in relation to the centre fin (52mm) than most I see. Back leading edge roughly aligned with strap back screws. The centre fin is a 155mm (labelled 16 cm) K4 Flex-fin. Which apparently is Graham Ezzy's favourite. This board is faster than my quads and easier to sail in a straight line than my previous twin. Although blasting around is not my priority.
Initially ran my SSD tri-fin with a 7" (17.8 cm) middle G10 fin. Found that too much area or stiff as turns were smooth and tight but not as snappy. A friend really liked it to loosen up his large 105 litre tri-fin board. From memory the side fins he had were quite large and this made it more responsive.
I use the quad boards when conditions dictate as they are bigger and what they where are designed for or came with. When overpowered, in rough conditions and in bigger waves the quad with a few more litres volume is more settled and controllable than my tri-fin. The "mid sized" quad configured as as twin is great in onshore mushy conditions (as long as upwind performance is secondary).
My previous dedicated custom twin was amazing for that, using 15.5 cm Maui Ultra Fins X-twins. These should also work well on quad boards if the size is appropriate. Their fin profile is quite narrow and upright which might be contributing to the tight turns possible. Appears to be a few other riders apart from top sponsored riders that like them. (They unfortunately don't fit on my quad boards without modification and are too big for my weight/them).
Running my smaller quad board with only two rear fins get's me close to the same experience. However, the general board characteristic are another major factor. Removing the side biters is an alternative way of reducing the fin area without sizing down the rears. Recently had a Fanatic Quad with relatively small 8 cm asymmetric sides with 1 degree inbuild toe-in which made it turn better and tighter than the original symmetricals. It had 14.5 cm swept back rears.
Generally I would say twin fin boards require more sailor input and the tail can be pushed loose easily. Have also tried the twin fin with a trailer fin. Even a 8 cm centre fin stiffened it up considerably, but obviously doesn't give it the same feel as a thruster.
At the other end of the spectrum my light wind board is a quad and good for schlogging up wind and early planing. It could be reconfigured as a tri-fin but I have not seen any need to try yet. The middle box has a resined blank so a slight obstacle to route out. Mark Stone recommended to use it as a quad. The tomo-tail shape is very wide and short. Which may suit a quad better than a tri-fin?
I've seen other tri-fin boards that have proportionally bigger sides. More like thruster surfboards. That would be interesting to try. Does anybody here have experience with that setup?
So whats the bottom line ? Twins=loose. Quads =control. Both could be fast. So tri sound more like the ALL season auto tyre thing-not too good for winter and not too good for summer... Look at the PWA top five-no one rides a tri fin on a regular basis, in the top ten only Traversa, Mussolini and Stone whoose total body weight is less then 200 kilos... This says a lot imho.
Maybe fair to say - all up - tri-fins setup is the 'most used' among pro's I would say ... quads close 2nd ... , twins a distant 3rd .... (maybe only Koster the only top adoptor)
Some brands like Tabou have gone down a 'all tri fin' route ... they felt in general ALL their team preferred the tri-fin set-up . Some boards by a quirk of shaping - take NANO 2 (tail kick extreme) , have to be ridden as quad for best performance ... Some guys look super natural on both - like Levi Siver - whereas someone like Marcilio Browne - always looks a bit more 'stilted' on a thruster vs his ridiculous quad antics ie re-writing wavesailing style with 270 degree full blown ninja turns) ...
I had a range of 5 box boards (from same brand) - The rockers (medium curve) - seemed to 'come alive ' with tri fin set-up ... combined with the more rearward strap / fin positioning that tri-fin set-up allows , vs the more fwd straps / quad feel ... (I sailed them quads for 2 years and was perfectly happy - before mixing everything up moving to tri-fin and finding an extra sparkle of performance ..)
Depends alot on the shaping ...
k257 quote - " Thrusters - usually fast to plane, piles of drive especially on the bottom turn. I find them to be very on and off - the rear thruster fin is quite long and can get often get stuck in the lip or the whitewater if you don't time your turns perfectly meaning you tend to either get a very good turn or a very ehh turn."
Or - that bigger rear fin can give you 'drive' out of the whitewater sh1tfest ... 1st time I used my 5 box as tri - couldn't believe the amount of extra drive / speed over a whitewater lip when you hitting a section coming towards you , it would chew up say 4m of high line whitewater lip line floater and get to the face the other side way better / quicker / more assertive than a quad .... And sometimes - that extra fin grip behind the backfoot is vital - like landing an aerial in aerated whitewater , or sailing OUT of stuff like wave360's , where smaller quad rears can slip when applying pressure to get out of the move .. and a tri-fin will 'hold' and give you fraction more grip and get you up and out a split second earlier ...
So depends what your priorities are ...
Maybe helpful for someone... I have been using 17.5cm mostly and sometime 18.5cm x-twins in my Ultra Kodes and Pyro 86 & 93 L. And been experimenting with quad in over 45+ knots to slow the board down for more control, still quad feels like dragging an anchor to me. So I just try to rely on my 100kg of weight to hold it down in big winds :)
I put the fins more forward with smaller sails and or cleaner waves, turns sharper. More back with onshore and bigger sails for traction. And 0.5 cm makes a big difference already. Just find the sweet spot for your sail-board-weight combination. For me it's usually 3.0 to 4.2 its in front and 4.7 to 5.5 bit further back. And if it's not good for 5.5 just leave it to the kiters :)
Tail shape seems to make a big difference too, rounded pin tail Kodes got lot of grip compared to really short tailed Pyro.
I can see why a guy like Koster likes twin fins as they are easy to break out when doing skaty moves on sloppy waves. Trifins and quads have more grip due to having more fin area on the rail. But most boards have small side fins and thus trifins need to have a big centre fin. Quads have more drag due to having more fins. Trifins or thrusters with three similar sized trifins are at least as loose and grippy. I use for example 3 x 12.5 or 12.5+14cm under an 80L, 13.5+14 under a 90-95L or 14.5+15.5 under an 105L. But when you have bigger side fins, it becomes more important they are set up correctly. The water flow under the board is directed from the centre outward so the further away from the centre, the more toe-in you need. But this effect is the biggest directly under the board and diinishes over the length of the fin. We use 2? toe-in and then the fins have another 2.5? toe-in in the base. The fins then twist back to pretty much zero toe-in at the tip, depending on the size of the fin. This may not seem much but water has a lot of power. We just can?t see it.
You can see the same principle on the wings of wind turbines, propellors or our sails: The angle of attack changes over the length of the foil thus the foil should twist over its length accordingly.
Going down a wave without lateral pressure of the sail, in this situation you do not want any of the fins to give lift to reduce drag and to help initiate the turn:
Image generated by CFD software of a bottom turn:
Image of a bottom turn in reality:
How the camera was mounted:
Also asymmetrical fins need more toe-in as the asymmetry starts to give lift and drag by itself if the angle is not adapted (like the wings on a plane give lift). About 1? for every percentage of asymmetry (also called camber). See images below which give the lift and drag of a 2% asymmetrical foil with zero angle of attack and -2.07? AoA at which point there is zero lift again and the least drag. The induced drag is 1/3rd with 2? extra toe-in (on average you need 2? toe-in for a symmetrical fin.)
We have also adapted our fins to boards with the side fin boxes set up paralel and they visibly became a lot turnier, faster with more grip and drive in the turn.
Does this sound complicated? Yes, there is a LOT more to it then just a centre fin. But this is what it is, it simply is what happens because of physical laws. The same physical laws that allow us to windsurf in the first place and if you want to do it right, there is no way around it. The first planes also flew but we still learned a lot more after that.
I always wonder when I read the discussions about toe in why a guy like Keith doesn't use it on his Quatro and Goya shapes.
Seems to be a reason and I'm sure it's not that he's willing to use only the second best solution for his boards.
Can anyone explain to me why quad fin setups are considered slow, draggy and planted on a windsurfer yet super fast and lively on a surfboard ? I have a shed full of waveboards but these days all I ride is my 86 ltr Quatro Cube. It seems to do everything and is the best around waveboard I have ever sailed. And it is super fast, loose, early planing and lively......and it's a quad.
When it comes to surfing however, I prefer thrusters because they feel more predictable but I will admit that my level of wavesailing exceeds my surfing.
Personally I think that what a board can do,and how it behaves, is less to do with the fin setup and more to do with the design of the board it's self. Excepting the probability that certain shapes may be suited to certain fin setups. Certainly true with surfboards. So is there really any point in 5 fin boxes ?
I would be interested to hear what people think.
I hope everyone is having a great Christmas and here's to a windy ( covid free ) new year.
Stony.
On a wave, the medium is tilted so you release the 2 outer fins... which are farther out on the rails.
In flat water, all 4 fine are engaged.
I never thought that fin selection is as complicated as brain surgery- who needs that and even if true-so what ? I have tried twins, trusters quads. Not to make things complicated I have picked quads(THE ultimate multifin sensation) imho. Watching Brawzinho and Levi destroying Pozo and Hookipa on production boards -Marcilio on quad and Levi quad/tri is enough said for me, a mere mortal, regarding the evergoing production vs. custom dilemma. Merry X mas to everyone and let this Covid nightmare remain in 2020!