Sideshore said..
Hello
Though side on/on shore are not my favourite conditions, I should improve my wavesailing performance to enjoy those days.
Lately we've seen many new stubby thruster boards which promise convert an on shore boring day into an action one.
I guess the old twins should turn easier and tighter but keep speed worse and have less upwind and planning performance than the flat and wide tail stubbies. There are also allround wave boards and even freewave thruster boards which pretend to be very good as on shore wave boards.
Did someone compare this kinds of boards in the same size and conditions to come to any conclusion?
Cheers
I'm going to answer this without reading what others have already written in reply. Maybe I'll make a fool of myself, but it's important here to understand what you are asking.
1. There are different types of boards and then there are different fin set ups. For example, what is a stubby board nowadays? (Most people think of that as a shorter board with a truncated tail and nose. But we've actually stopped using that term since all wave boards became quite short. Most new wave boards are either old school, at 2.30cms long, or new school at 2.20cms. In either range, they still get longer and wider as their volume increases)
2. And in fact all types of board can be sailed with different fin set ups. Those fin arrangements simply need to work with the board design and hull shape.
2. Twin fin set-ups line up one relatively-small fin with its adjacent/paired second fin. Both fins produce lift but only when you are moving forwards - which is why they don't take sideways load until you are planing. That fact in turn affects what early planing technique you use, because you can't load the backfoot until planing. If you have no early planing technique, then you hate them.
3. So twin fins are sloppy tailed when going slowly but can rotate in a tighter arc in a turn because one fin can follow the path of the pair leader. Twin fins are actually quite fast, in the right hands.
4. Board speed relates first to hull shape - and to the rider - but fins will be slower the more you have. The fin drag comes from surface area relating to the fin size, and there's secondary drag from the tip vortex of each fin.
5. The fin advantage of a Tri fin set up follows that of the old-school single fin . If you stick a long centre fin in your board then that allows the fin to produce leverage or torque at the board tail. You use body weight to hold that toque down and that in turn allows the board tail to lift, and for the board to then fly at greater speed on a short tail length - like with a slalom board. But that same torque lift is then problematic in the turns, with the tail wagging the dog when the board travels at top speed. So we generally say that tri fins can be fast and they help for jumping, but are less loose in the gybes and on the wave face. But, as with all fins, that also depends on what fin length you use. In waveboards, tri fins work just fine as a simple compromise - until you stick too long a centre fin in your board.
6. One top tip with all wave gear is to not use long fins if you want to wave ride. If your focus is for jumping then go 1 cm longer on the centre fin, but maybe ruduce the thruster fin size. .
7. You then mention onshore conditions, where wave riding is more difficult but where jumping can sometimes the easier. So, what do you personally want to do? Twin fins are not slow, and can therefore jump well (note Mr Koster's choice of fins). The tri fin set up however can be simpler for those still learning to jump and ride.
8. If you are tempted to put longer fins in your board, then maybe get your technique and mast foot set up checked first. People who use too long a centre fin, or too much fin area, are usually the same people who set the mast foot too far forwards.
9. Personally, I think I'd focus on board shape and board size first, over fin choice. Thise are the key things when adapting to different conditions. For onshore, you need more float, and less board rocker. You don't need to use the word 'stubby' anymore.
10. I may regret some other these sweeping statements in the morning. Who knows?
!
