I was playing around with the mast track position on my Tabou Rocket 115 for more speed. When the mast track is in the back half, the board is really easy to spin out (stock freeride 36cm fin and sail sizes 6-7.5m). When it lets go, its gradual and can end up with the board crossed up at 45 deg to the direction of travel. The board feels faster with the mast track further back but feels on the verge of a spin out once you apply some back foot pressure.
If I set the mast foot forward then I can put all of my weight through the back foot into the board. The nose rides lower and feels slower. Perhaps it feels slower because it's more controlled and comfortable, but it's not?
Is this normal? Or is it a problem with the equipment/technique?
I think it's normal, I've read somewhere advice for speed sailing, "move mast track back till you start spinning out, then move it forward a tad."
With mast foot forward, and board riding flater, you have more board in the water so it's slower.
With mast track back and less board in the water, there's more likely hood of air reaching the fin, so it will ventilate earlier.
It's a compromise of how much back foot pressure you can use and how fast you want to go.
Chop will have a big affect as well, smoother the water less likely to get air under the board.
Sounds normal. Mast track forward = more leverage on the front of the board = more wetted area = more drag = less speed. Mast back = less board in water = more pressure on fin = more likely spinout.
On my first "funboard" - an F2 Sputnik - the mast track was graduated in numbers as usual, except for the rearmost possibility which was labelled "Speed".
I usually just run my mast foot 135cm from tail and only move it forward/back 1 to. 3cm depending on conditions. I have a similar set up to you, 114 and a either 6.6 or 7.5. I run a 39cm fin for both sails but find it maybe slightly to small when the wind is on the light side with the 7.5' so maybe excess spin out could be caused by your fin being slightly to small if your useing your 7.5?? Also maybe try and getting more weight through your front leg so you can absorb chop with your bent back leg. I find if I hit chop with my back leg loaded spin out results. Another idea is to put your harness lines back a couple cm( = less force through back leg) I was given this advice when I was having troubles spinning out, made the world of difference. Just some ideas, hope it helps.
When I moved to small fins on my FS board, I found it really good advice to move harnes lines a bit to the back, so you don't pull so much with the back hand to sheet in and consequentially applying less preassure on you back foot as well...
it's a matter of 2-4cm...
a nother thing was to ride more of the front foot.
I used to own a 115 rocket.
My main fin was a 38cm jp glass fin for 7m+ sail.
This setup used to hammer in light winds, dont think i ever had a spinout on that setup tbh. Also I remember i had the mast track in top 1/3 position.
Thanks to everyone who replied. I will try the harness lines further back, good point and simple enough. I will get some other fins just to try and see how it responds.
Dark plague, good to compare notes with someone with the same board. A friend that I sail with has a 125 rocket and he has the mast track almost all the way back. I sailed his setup with a 6.6 and his stock 44cm fin and no hints or signs of a spin out.
I usually find that as I move the mast back, I also move the boom up to create a bettr balance and more drive of the fin.
Hey GusTee,
Found this article, just adds another point of view, to good points already said by others.http://www.boardseekermag.com/features/technique/mastfoot-position.html
Kind Regards
Walt
The main cause of spin out is incorrect sail tuning.
so the first thing to do is pull on some more downhaul.
You are moving the mast track back to look for more speed which is fine but trying more downhaul is part of that search for more speed. You want the sail to be driving you forward not sideways.
Starting point would be to get a quality fin and then you may well find that the standard fin is just a dud.
