Looking at sail options for a Severne Fox 105. Thinking 7.5 Turbo GT as the biggest I could get away with. Severne recommends max 7.8. I always assume manufacturers go over and under by at least one size. My question is at 70kgs, Im on the light side for the board. Does this give me more scope at the top end of the sail range or less?

Maximum sail size is always a funny thing. There are sail sizes a board is comfortable with, and then there are sail sizes that are a step too far, or an 'overload'.
The point of overload relates to four things: 1) Board volume combined with its width, 2) Sailor weight, 3) Rig weight. 4) Style of sailing.

So, under 1), a 105 litre board can take a 7m sail but starts to be overloaded with a 7.8. With a big sail you'd then be blasting along rather than turning - so that comes under 4).
2) Sailor weight also makes a difference and a lightweight sailor doesn't actually need such a big sail - and 70kgs sinks the board less than the heavier guy's 90kgs would.
3) You can get away with a big rig if the rig itself is light - with a full carbon mast and quality boom etc. A rotational sail is lighter than a cambered one. But note that sometimes to get half a metre more sail area you often have to go to a longer mast and boom and so the 8.5m rig is way heavier than the 7.5 model from the same brand.

I have not answered the question because it's something you have to discover for yourself. My personal view is that using too big a sail - near the upper recommended limit for any board - simply takes away the fun to be had with that board. Given a choice between two sizes, I'd rather use a smaller rig with the downhaul and outhaul eased a bit.

Absolutely spot on. I tried a 8m Hyperglide on a Patrik 100 with a 38 carbon fin and no matter how hard I tried I could not get the thing upwind.

With a 7m the boards goes upwind with ease.

Ben Severne uses a 7.5 OD on his 105 Fox from memory but this is pushing its limit I think.

I had a fox 105 and worked real well with 7.5 NCX and I'm 82kilos. I used 38 fin with 7.5 and was fine at all points of sailing 8mtr is to big for that board.

Select to expand quote

Basher said..
Maximum sail size is always a funny thing. There are sail sizes a board is comfortable with, and then there are sail sizes that are a step too far, or an 'overload'.
The point of overload relates to four things: 1) Board volume combined with its width, 2) Sailor weight, 3) Rig weight. 4) Style of sailing.

So, under 1), a 105 litre board can take a 7m sail but starts to be overloaded with a 7.8. With a big sail you'd then be blasting along rather than turning - so that comes under 4).
2) Sailor weight also makes a difference and a lightweight sailor doesn't actually need such a big sail - and 70kgs sinks the board less than the heavier guy's 90kgs would.
3) You can get away with a big rig if the rig itself is light - with a full carbon mast and quality boom etc. A rotational sail is lighter than a cambered one. But note that sometimes to get half a metre more sail area you often have to go to a longer mast and boom and so the 8.5m rig is way heavier than the 7.5 model from the same brand.

I have not answered the question because it's something you have to discover for yourself. My personal view is that using too big a sail - near the upper recommended limit for any board - simply takes away the fun to be had with that board. Given a choice between two sizes, I'd rather use a smaller rig with the downhaul and outhaul eased a bit.

Thanks Basher. Good points. I do love blasting, but the sailing is a lot more fun if you can get the board around the corners. The problem with discovering for myself is I can only afford new gear about once every 5 years, so finding out for myself that the 7.5 Turbo is too big sucks quite a lot. So I conservatively order the 7.0 and potentially miss out on a bit of speed or TOW but it feels great when Im on the water.

Also Peter, Ben Severne's form is probably just a little better than mine, a good add for going down a size to the 7.0. Still interested in the theory of whether being a light weight theoretically extends or reduces the upper sail size on a given board.

I've used an e-type 8.2 and GSR 8.2 with my Fox 105 which felt fine, but I think that really was the max, especially with the cambered sail and shouldn't be a first option . My Overdrive 7.8 is wonderful with it but I think the sweet spot is 7.0. Shame 7.0 wind is a rarity here!! I'm about 78kg. Better strategy for 7.8 and up has been to go up board size.

Matching sail sizes is indeed a strange equilibrium that is very much down to how the sailor feels about the rig/board/and conditions. In addition to their weight


im somewhere between 65-70 kg, i own 60 wide, 71 wide and and 85 wide (with a wide tail) isonics and theyre all relevant boards for me at one time or another. The sails i use are 5.7, 6.2, 7.0, 7.8 and 8.6. All of them are race sails.I've figured out that the 8.6 is well and truly overkill at my weight. By the time it starts to feel powerful, im already thinking my 7.8 would be powered up. And it moves quite quickly to overpowered.

as for the boards in between, even as a fly weight i feel that generally speaking the recommended sails are generally on the ball. I also find that sometimes im better off with a smaller board and bigger sail combo as the bigger sail actually "holds" the board down better because its a more stable sail, for example a 7.0m on a 60 wide feels more controllable than the 6.2 on the same board when its pushing up towards 25knts.


now that i've posted all that pointless drunken almost completely unrelated mumbo jumbo above, i guess i should actually give my opinion (humbly): a 7.5 turbo is a light sail thats still well within a range for your weight where it won't be hard to handle. Your lighter weight will let you keep planing for longer than a heavy weight when using the same sail size when the wind drops. But contrary to poular belief, i rarely find my weight allows me to get a smaller board going sooner than those that are heavier than me. I need to change board widths to match what they are using to get going when they do.

Select to expand quote

Nelle said..
Looking at sail options for a Severne Fox 105. Thinking 7.5 Turbo GT as the biggest I could get away with. Severne recommends max 7.8. I always assume manufacturers go over and under by at least one size. My question is at 70kgs, Im on the light side for the board. Does this give me more scope at the top end of the sail range or less?

Hi Nelle, I am 72 Kg and I used to put a 7.3 on a Patrik Slalom 100 (64.5 cm wide). I could have used a bit bigger, but 7.3 was big already and the board probably would have been easily overwhelmed unless you were pointing downwind. If anything I would think that the Fox, with its narrower tail and freeride tilt, would be less capable of carrying a large sail.

But it depends on the sail, and a lot on the conditions. Steady powered you'd probably be ok with a 7.8, unsteady and overpowered you'd be really pushing the limits of the board and it would not be much fun. If I were you I'd stick with the 7.5, 0.3 more does not buy you anything, and consider a no cam sail. Get a Point-7 ACX and your Fox would go as fast but be much easier to handle.

Another way to go is changing fins, cheaper too! try a larger/more powerful fin with your 7.5 to add range in lighter winds - nice to have 2-3 fins for each board

While it's true that lighter sailors can get away with a bigger sail on a smaller board, I don't think you will get more bottom end with a sail bigger than 7.0 on that board. If earlier planing is a must, I would look at slalom or freerace boards. Slalom boards are way more technical to sail, but they get going before anything else and extract all the performance out of big rigs.

Select to expand quote

duzzi said..

Nelle said..
Looking at sail options for a Severne Fox 105. Thinking 7.5 Turbo GT as the biggest I could get away with. Severne recommends max 7.8. I always assume manufacturers go over and under by at least one size. My question is at 70kgs, Im on the light side for the board. Does this give me more scope at the top end of the sail range or less?

Hi Nelle, I am 72 Kg and I used to put a 7.3 on a Patrik Slalom 100 (64.5 cm wide). I could have used a bit bigger, but 7.3 was big already and the board probably would have been easily overwhelmed unless you were pointing downwind. If anything I would think that the Fox, with its narrower tail and freeride tilt, would be less capable of carrying a large sail.

But it depends on the sail, and a lot on the conditions. Steady powered you'd probably be ok with a 7.8, unsteady and overpowered you'd be really pushing the limits of the board and it would not be much fun. If I were you I'd stick with the 7.5, 0.3 more does not buy you anything, and consider a no cam sail. Get a Point-7 ACX and your Fox would go as fast but be much easier to handle.

I would go the no cam option, I'm replacing a much loved but on the way out Severne NCX 7.0, my favourite all time sail, but I want the cams for foiling. the NCX doesn't go well on the foil. I haven't owned or sailed a camed sail since my Wild Winds Speed sails around about 1990. I have been assured I will like the Turbo GT. Its very free ridey.
Its Port Phillip bay, so its choppy, like washing machine choppy and almost always gusty. I will go with the 7.0