Recently, I purchased a huge sail and 250+ boom so that I could plane in light wind days. Yesterday I had the rig up and out and was planing. However, I have to trim the rig. I'm not using a bona fide formula board, but a freeride 160 with a weed fin. I figure I have to put the mast track full forward in that I'm having some trouble that probably stems from having the CEO too far back for the board. 11 meters remains the upper limit for the Icon. It points up too much when water-starting. I was also feeling some serious pressure on the front hand at peak winds while riding in the straps. It felt like I was back-winded. Do you think I'm proceeding the right way? Do the small increments in mast track position on modern freeride or freerace boards translate into wide differences in trim?

God they're big numbers. 250cm+, 160l, 11m. Beyond me.

I'd spend a session dedicated to adjusting trim elements one-at-a-time. Harness lines, outhaul and mast position are pretty easy to adjust on the water.

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Do the small increments in mast track position on modern freeride or freerace boards translate into wide differences in trim?

On my Starboard Carve, yes.

By front hand pressure, do you mean you're having to push with your front hand to counter the front of the sail coming in towards you?

If so, this sounds like the sail is trying to sheet out - remember that you can sheet out the sail either by pushing the back of the sail out OR pulling the front in.

Maybe your setup is oversheeting the sail? This would suggest that you've maybe got your lines too far back, or lines that are too short.

When I first tried a 9m cammed sail on my 155 Go I had to really lengthen my lines from what I was used to, and brought the lines quite forward so I was comfortable but with pull on the backhand, then worked the lines back incrementally.

Regarding Mast tracks, on modern freeride boards I've found most have a sweet spot. Once you find this spot you only need to move it a cm or 2 forward/back for a bigger/smaller sail. Just because your mast track is 25cm lg you don't need to use all 25cm for the boards sail range.
Then again I've never used an 11m sail.

I wouldnt be too concerned about having trouble waterstarting an 11m sail...

Interesting topic as I've often wondered whether there should be a relationship between harness line position and masttrack position.
For example, if you have a smallish sail and found the perfect setup positions for mastrack boom height etc etc etc. so that everything is perfectly balanced in your sailing position. Then if you went up to a larger sail size and if you know the harness lines will be 8cm further down the boom, in oder to maintain that perfectly balanced spot the masttrack would need to be 8cm forward and the boom raised a few cm to allow for the slope of the boom. In practice I don't do this but does it sound correct or reasonable

Although it might take a little longer to get it up out of the water!

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sailpilot said...

...to maintain that perfectly balanced spot the masttrack would need to be 8cm forward and the boom raised a few cm to allow for the slope of the boom. In practice I don't do this but does it sound correct or reasonable

The direction sounds right, but the size of the shift sounds too big to me. I'm not sure why but in these circumstances I think I'd only be shifting the mast forward a cm or two at the most, and I wouldn't bother with the boom height. Maybe I should...

In practice I shift the mast more to gain control OR power depending on how the wind changes, ie whether I'm under or overpowered.

The mast track position trims the noise of the board up or down "NOT" centre of effort, thats what the down and out hual on the sail does.

In most cases the bigger the sail the further back you can put the base because its heaver and trims the nose down.

Boom hight also has this effect and if you change one it effects the other, You can move your boom up and mast forward and keep the same trim or move your boom down and mast back and keep the same trim. Move one of these and you change the trim.

I think your problem is more how your rigging the sail and if you get this right first
then worry about getting max trim, Work towards boom up high and mast back but start at the other end first boom down and mast forward and move 2cm at a time.

If you start getting the nose flying up lower your boom and or move the base forward, Otherwise boom up for max lift

And more down haul should do the trick!

Yes TristanF thats same as I do but it just doesn't seem right, dunno why.

Gary, your correct on these affecting the board trim but I was more looking at it from a better balance perspective, it doesn't gel with me that the bigger sail should go further back on the masttrack because the CE is already further back in the larger sail, so what was nice and comfy on a smaller sail is now going to be very back leg heavy. The downhaul shouldn't matter as going up in sail size is basically looking for more power so a soft trim is most likely wanted as well.

Hopefully this wind drought will stop so I can try the ideas out on the water.

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TristanF said...

By front hand pressure, do you mean you're having to push with your front hand to counter the front of the sail coming in towards you?

If so, this sounds like the sail is trying to sheet out - remember that you can sheet out the sail either by pushing the back of the sail out OR pulling the front in.

Maybe your setup is oversheeting the sail? This would suggest that you've maybe got your lines too far back, or lines that are too short.

When I first tried a 9m cammed sail on my 155 Go I had to really lengthen my lines from what I was used to, and brought the lines quite forward so I was comfortable but with pull on the backhand, then worked the lines back incrementally.

Yes, that described the experience, but it only happened on my last reach on one tack with the wind at full throttle. Hopefully it isn't the harness line length because I extended the possible length on my adjustable lines to 36" and have been using 34" to 36". Position of the lines could be behind it.

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garyk said...

The mast track position trims the noise of the board up or down "NOT" centre of effort, thats what the down and out hual on the sail does.

That statement is about as correct as the way it's spelled. Mast track forward= nose down, increased wetted surface, better upwind ability, and COE forward in relation to the board and fin. I know that much about it.
More downhaul will mean buying the recommended mast, a 550 which costs a lot. Right now, the sail rigs correctly but allows me no ability to increase the downhaul and loosen the leach fully.

A good manufacturer will normally recommend a mast track position.
As a rule the centre is the design sweet spot for the specified sail range of a modern board. Secondly it is normally recommended that you only move it 10-20mm from this position. Foward to trim the board flat/ make it more controllable.

I basically use the same settings for all of my sails and boards. 77l wave board with 4.2m up to 120l Freeride with 7.5m. That is mast foot in the middle, boom at armpit height, and use crib sheets for harness position, and just under a fist apart.
The only difference is I use 28" lines on my 7.5 and 26" for everything else.
Works mint pretty much all of the time.

The critical element is sail tuning. Not enough downhaul or the incorrect mast will mean the sail does not twist off and exhaust air properly. If a sail is trying to twist on you it is due to it not exhausting correctly. Scary sensation as it often happens as you get up to speed or get a gust it may try to backwind. With a correctly downhauled sail you should be able to sail no handed or one handed and handle a gust without raising a sweat.

Messing around with all the other settings too much ie. mast tack postition or boom height will compromise several other aspects of sailing. Ie jibing, tacking and water starting.

Im no expert, but I have done my share of messing about.
Hope this helps.

Well, it all helps in the way that the truth hurts. I know I'll do better if I buy the proper mast, a 550 100% carbon mast. However, I can't afford it right now. Have you looked at the price of these things lately? I figure I was back-winded in a strong, long lasting gust when the wind wasn't spilled-off as it could have been with more downhaul. That basically means that I should continue to sail but avoid over-powering gusts. However, it doesn't mean that I can't move the mast forward a few centimeters. I think the rounding up while water-starting has a lot to do with the balance of the sail COE and fin COE. I may have too small a fin, too. Maybe by going to a straight fin (not a weeder), I will see things differently. I don't need it for weeds so much as shallows. Unfortunately, though, hooking up with such a large sail has to be a rather traumatic experience. I've done it with smaller sails and fins. Thanks all for the suggestions. For your information, be careful about low priced sails. I got an incredible deal on the sail which was brand new but an '03. First I bought an Alu boom which also fit my 9.6. I had been sailing with the 9.6 on a carbon boom fully extended, but thought I was running a risk of damage by overly stressing the boom by point loading. The alu boom was too soft for the 11 meter. Consequently, I found a good carbon boom at a reasonable price. Now, though, the costs were mounting. A 550 mast will put me over the top, and I'm tempted to find a Formula board. Is it all worth it?

thats some pretty big sails, i thought it was windy in wa?

Rubby - not sure what type of sail you are running - freeride or race - so i could be wrong with the following but here goes..

"More downhaul will mean buying the recommended mast, a 550 which costs a lot. Right now, the sail rigs correctly but allows me no ability to increase the downhaul and loosen the leach fully"

Bit of a contradiction - the leach should be pretty loose a fair way down to be rigged correctly. Some brands are suggesting only small 2-4 cm min max downhaul differences and using outhaul tension for trimming - ie the leach should be pretty open at all times

i made a mistake of rigging to the manufacturers spec - the leach only opened slightly (2nd batten down) - until someone (thanks Barry F) told me I needed more downhaul - I ended up with 3cm over spec (although I havent measured the mast) but what a difference - up until doing this i was concerned how the sail was going to be when NSW finally got some decent wind (read over 10 knots when i wasnt at work) as it felt quite unwieldy - similiar to your backwinding

With the correct downhaul the sail was transformed, it no longer felt like it was going to pick the board up off the water and throw it - it just spills off and drives and i use the outhaul for trimming

You could try -if you arent already - running a tip extender. Mast sail compatability is another issue altogether and yes 550's arent cheap - i could only afford well cared for second hand 550 / 520's which is something I never thought i would do - but at almost $3k versus $920 it was no contest - and kept the bride off my back

as for trying to waterstart an 11m sail - thats INCREDIBLE - uphauling is enough

Ben, thanks for the feedback. I've re-thought this and come up with another solution. I was basing my rigging on my universal/extention and the sail's hardware. (This is a full blown Formula Race sail.) It has a three roller/one cleat piece for the downhaul. My three roller/one cleat extention is too long when I rig the 520 with 50 cm carbon extender. I can rig it without extention (old fashion set-up), but then it allows no extra downhaul and rigs with a minimum twist-off in the upper leach. However, it recently dawned on me that can use a two roller/one cleat extention and put in adequate downhaul. The threading may not be perfect, but it might save the expense of a 550 for a while. I am going to see if it works today in the backyard. By the way, I checked my profile. Sorry, I'm not in WA. I spend my winters (Nov to March) in Florida which isn't very windy any time of the year. As to those who are intimidated by sails this size. First of all, you have to be large to use them. I weigh in at 230 lbs. Second, when I went to an 8.4 four years ago, I was apprehensive about it. Then when I went to 9.6 three years ago, I was scared stiff. Now, it is my most used sail and has extended my windsurfing days incredibly. I have to be in shape for these sails, but they are not impossible to use. In fact after extensive practice, I can use them better than smaller sails in high winds. The 11 was just as intimidating as the other sails were, but I really found it sailable. In fact, it was rather enjoyable getting on a plane in winds in which I have been resigned to slogging for decades. With a little practice/experience, I might be considering a 12.5!!!