VIC
4 posts
hey
this may have been asked but i cant find it....
how do u prevent the board from sliding?
i kno when it does slide u have to bring your bak foot in to get it in line again but is there a way to stop it before it happens?
also back in January sum time found a Small wave board fin and mast step left at elwood beach on the grass bank? Msg me bak if its yours
thx
WA
12884 posts
Wow that's a difficult one, there's so many causes of sliding, (fin cavitation) and each one can have different remedies.
If you can describe more precisely when it hapens, that will help.
ie
how powered up are you?
how fast are you going?
going upwind?
going downwind?
Fin itself is also important, what style, how big? how flexi? Is it adjustable? if so where is it in the box?
What sort of board, what size sail, what wind strength??
Not to metion how the sail is set, and your sailing technique.
If the first lot of parameters seem ok we'll come to them later.
WA
1160 posts
to much pressure on your fin.. drive off your front foot more..less wight on the back foot..
SA
924 posts
Yeah this happens to me a bit aswell. I thought it was mainly caused from having a to smaller fin.
For me, it mainly happens when i'm goin along in chop and hit a bigger wake, and then when i come over the top the board starts to jump around and then slide out from underneith me. I can somtimes get it back under controll but more often than not i stack it.
bubs
WA
12884 posts
Bubs, this sound more like technique, take the pressure off the back foot when going over chop. You can easily get air around the fin as you go over the top, any pressure on the back foot will drag the air down the fin and you'll spin straight out. A bigger fin may help a bit, but then you can have problems "railing up" also causing spin out.
If the fin is adjustable you could try moving it back a bit, (less chance of the leading edge getting in the air). But this can cause the opposite problem, sucking air down the back edge under load, (happens when pointing high, or more back foot pressure.
I've found fin position to be critical.
Too far forward, spin out at speed (downwind)
Too far back, spin out under load, (upwind)
Another factor is the way the sail is set. If the shape is too far back the "lift" of the sail is pulling sideways instead of forwards, putting more load on the fin. Commonly more downhaul will help.
Missed one
Harness line adjustment!
If harness lines are too far forward, means more force on back hand, this transfers to back foot, spin out!
WA
44 posts
the thing that i found when i was sliding out was the my back foot strap was to far back, so try to moove it forward if posible and make sure that the back bolt on the back foot strap insnt any further than 1 or 2 cm over the fins base, so this takes the presure off the fin so theres less chance of sliding, well thats what i found
WA
6277 posts
If it happens, head downwind and sheet out.
WA
1109 posts
stubbings if your goin out on a 130 lrt board in 30 knotts that may be another problem, you see the higher the wind the less volume of board, im 75 kg, and if it was 30 knotts i would be out on a 80 lter board with a 26 cm wave fin, i bet you find it very hard to controll the board and sail when its as windy as today, try and find a mate or some one who will let them have a go at there smaller board, and see if you slide around and bounce the board around as much, i recon you wont, and also make sure the fin is flush without the head sticking out if it is give it a good sand wiith some wet and dry sand paper antill its flush, thing give the board less change of spreding air around the fin
NSW
1125 posts
Assuming you have the correct board/sail/fin for the conditions...
What worked for me was to slide the harness lines back one inch and the mast foot forward one inch.
WA
255 posts
Agree with Decrepit
I reckon 90% of spinouts can be avoided by quite minor tweaking of your rig/stance.
I would always set your fin in the middle of the slot (see decrepits post)
When you rig make sure you have the correct downhaul (and the right mast stiffness). If you downhaul too little the sail's power will come from further back across the sail and will make you load the fin more.
Make sure your harness lines are set exactly in the centre of effort of the sail, you should be able to sail without holding on hard with either hand.
Use the harness lines, try and hang most your weight off the harnesss, this will increase your MFP and take alot of pressure off the fin
Be light with your hands and feet, don't hang on the boom and push with your feet.
Make sure your fin is clean and not chipped, weed also causes spinout,
sailing in whitewater or someone elses wake increases your chances of spinning out so be extra light footed then, don't power on when you know your fin is going to come out of the water like going over chop etc.
SA
924 posts
Yes i've found heading downwind and sheeting out helps get back under controll a lot.
bubs
418 posts
5.7 and 120 litre board in 25 - 30 knots ?
Much too big sail and board for sure yar
Trying of smaller board and sail size in these conditions
Give or take 5 litres to your weight for board volume... example for referenceing... if you weight 80 kilo... 75lt to 85 litre more of suited to your weight and wind strength... the bigger wind the smaller you can be going for volume (and sail size of course yar)
WA
12884 posts
Yep as Kremlin says sounds like you hyave too much board and sail, but you neglected to tell us your weight, think you'd need to be over 100kgs for those sizes to be ok.
Is the board "railing up" ie windwood rail coming up? This will let air under fin an spin out.
Somebody did come up with a formula for fin size, but I've got no idea where I saw it now.
Basically the slower you're going and the bigger the sail you're using, the bigger the fin you need.
QLD
756 posts
If it keeps happening after the above get a bigger fin.
NSW
1173 posts
I was out yesterday for a blast at Botany Bay with a 140 ltr board, 8.7m sail and 43cm fin. Apart from the back ache I now have i found the set up was perfect until the wind picked up. An 8.7m in 22 knot gusts is a little difficult to handle! When every big gust came through my harness lines felt too far forward, i had to use the back hand to sheet in, when doing that I'd get major spin out. Normaly on my wave boards I get rid of spin within a metre, on the kit yesterday it took a good 30 metres of kamikaze down wind sailing!
As soon as i moved the harness lines an inch or two back i didn't get any spin out.
So make sure you don't pull too much with the back hand as you will push too hard with the back foot causing spin out. I've never had spinout from having a too small fin - i just end up with rubbish up wind performance!
