With the obviously extensive experimenting you have done to obtain an adantage,Whats your opinion on end v centre sheeting(Minis and fives) Have you swapped and changed to see what effect it has on speed increase or otherwise. I have constantly swapped about with full end forward to mast base to rider
Centre to rider .
End to centre to rider
A complicated system from end to front to mast base then up to centre and to rider (The centre pulley being suspended below a tube to allow the sheet to run free from end to front in the tube( if you see what I mean)
I have used normal sails and various windsurf rigs, (With the w/s rigs you obviously don't need to have a pulley at front of the boom since the downhaul is independent of the sheet to an extent)

The effect of these systems are ....... With the fed 5 ,wide axle and 55kg,the only time I can cause a hike(In moderate wind)is if the sheet is in the end position.

With the mini, Home built but near enough to 5.6 spec,with 5.5 standard sail and 6.2 w/s only time I can prevent constant hiking is with centre sheeting.
Neither yacht suffers from weather helm, and both stay straight with feet off the pedals regardless of sheeting.

Don't have a GPS ( I know )Probably should get one, and the few guys I regularly sail with have only smaller sails, blowkarts ,X sail So normally they don't match me for speed regardless of my sheeting systems.

The question,.... is hiking caused by an increase in power to the whole frame therefore potentially more speed or simply that the power is directed more to the rear axle .

Have you also tried out sheeting systems and found any benefit .
I also read that ,think it was Landyacht on here ,prefers what he describes as a rocking horse system but can't find any details of that.
be interesting to have any opinions ,

The short answer is no!

I weigh 110 kgs,243lbs so I'm always sailing overpowered with large windsurfer race sails.
I'm always almost on the point of hiking when pointing high upwind. As soon as a wheel leaves the ground point higher, use that mast flex to power you forward. It just kills your speed sheeting out.
I realize I'm twice your weight though so you are busier on the sheet.
Also you can exert a lot more sheet tension, much more easily (without realizing it) with the blocks on the end of the boom.

With windsurfer rigs centre sheeting is defeating the purpose (as you mentioned) as the downhaul controls the fullness of the sail independent of the sheet tension. I'm talking around 600kgs plus of downhaul tension. The composite mast curve is well over 1000mm on a 5.8m2 sail without any sheet tension at all.
The sheet will continue to flatten the sail, but the downhaul sets it up firstly for its full range for those particular wind conditions.
That is why we can readjust the downhaul separately while sailing different legs. It gives us the ability to fine tune the sail on the run.

Outhaul is always fixed "drum tight". We want the sail/mast to twist off in the gusts not flap like old ladys washing on the line when there is no sheet tension. A vibrating mast/sail produces bugger all power and much less traction. If my sail vibrates at speed it gets recut/sewn till it does not. Not very often this is needed on a windsurfer "monofilm" sail, but it does on a soft sail.
Without any sheet tension at all the sail will just weather vane to the apparent wind and sit there at any speed.

A drum tight sail skin accelerates so much more quickly out of a change of direction as the airfoil is locked to shape and is more easily trimmed. I get laughed at with all my "tell-tales". For very light wind they need to be up much closer to the mast and much higher up the sail. (you want power in all your sail in these conditions).
90% of my time sailing is spent watching the compromise between top and bottom tell-tales for maximum efficiency/speed.

I never sail without a GPS watch on my wrist as it's hard to tell a 4 or 5kmh increase in speed as you trim.
Tell-tales" wind indicator and GPS = more speed. Upwind "pointing high" and maintaining speed and downwind are where the greatest gains are. At my last State championship racing in Perth I was 4-5 kmh faster than other yachts on their radar gun in both classes.

As for centre sheeting, my Class 5 has it on my "Alligator" 5.5m sail and alloy mast and to be perfectly honest it does work really well... until you have to sheet out a lot and then the boom tries to kill me due to the flapping sail. Also the lack of mechanical advantage increases the sheet load by a huge amount which is tough on my old hands and wrists.

Landyacht is a freak at yacht design as he does it so well.
I have tried to sail both classes of his yachts. I find my weight is to great behind the centre of effort and they are too light on the front wheel for me to have any steering authority even with my knees up under my chin hunched as far forward as his design allows. He's MUCH slighter in build than this old farmer.
His ability to "aerobrake" around markers is his true trade mark.

thanks chook,think gps is on list,its prrobably the only way to test properly, The last time I was 55kg I was about 12 weigh in at 90,

Will keep experimenting,after getting gps and report back.

as an addition Its the fed 5 that is 55k, Chook, it's interesting that you favour w/s rigs So do I,They as as you describe ,solid foils. Before I retired for the second time in my life ,I worked for a Windsurfing centre ,and for 15 years an instructor .Was also for ten years before that involved in W'S racing at a club level.
Back in the 90ies there was a massive amount or R and D going on with the major sail brands Neil Pryde and North being the go to for the top end race sails. . The club race scene limited the sail size to a max of 7.5.so any advantage you could get was well tested out.
This was before the introduction of formulae boards and massive 10 and 12 m sails,we used long narrow boards with a retractable centre board(dagger as it was referred to)' These systems were more akin to dingy sailing than windsurfing.

Its interesting that you use an adjustable downhaul ,many tried this and its did work,however it was shown that there was a greater advantage in an adjustable outhaul.We used to set the downhaul till the leach was floppy and falling away from the tip to about the third baton down ,get someone to stand on the base of the mast with the boom fitted and then press down on the tip,to simulate power in the sail,if all the loose leach tightened up the sail was set,adjustments made to get to this stage. The downhaul was then left as set.

Its obviously more difficult to rig up and use an adjustable d.haul on a windsurf, as against a L/yacht but some did use both.

One thing that did convince us all that the outhaul was the better control ,is. If in anything like a planing (Aquaplaning) wind,the outhaul slipped or snapped the sail developed so much power that it was about impossible to hold on to the boom. It drops all of the foil into the front of the sail.And if you didn't unhook from the harness quick enough it would throw you over the sail and slam you on your back into the sea.

Pryde sails manufactured a boom with triple pulley system on the clew and cleats on each side so you could alter the outhaul depending on which tack you were on. I have one on the boom I use with the L/y with W/S rigs Only needs about3 inch of adjustment to get from deep foil to flat.

Wonder if you have tried the same(Probably have)

The main question I was curious about,and looking for theories,was because I found hiking was caused by end sheeting, therefore introducing more power to rear of yacht, does this cause an increase or decrease in speed or does it just introduce sideways drag, prior to the wheel lifting ,the only thing commented on in the various water yacht sites is rudder handling and cockpit space no mention of performance differences'
Going to have to get a gps me thinks

Ha ha I thought you must be a skinny bugger at 55kgs. Yacht weight 55 instead. Greg I sail with is only around 65 kgs so you had me thinking.

Thanks for all that information. I cant get enough of everyone's first hand experiences!!!

On soft sails yes I found adjustable outhaul works fantastically well but had very little effect on the monofilm sails. (Severn Reflex and Neil Pryde Evo's). You have me thinking now as I didnt have adjustable downhaul on the run at that time so will definitely revisit this.

I still have 2 Etrex 10 GPS and a now use a Suunto Ambit 3 watch that I love and I've had now for 4 years. It's great to have it on your wrist where it's always easy to read when your sheeting, no matter what the suns reflection is doing. Just needing glasses as I get older.
I use Safety Glasses sunnies with the tiny magnifying lenses at the bottom to make it easier to read.

Friends that I sail and kite buggy with on the Australian East coast are reporting good results with these cheap GPS from Flebay. No personal experience with them though.

www.ebay.com.au/itm/203333384896?hash=item2f579d3ac0:g:DhsAAOSwIUhgZ1a0

Cheers.

An update, the result of extensive testing with rear and centre sheeting.swaping about and switching yachts at each session

On a light wind day,below15 mph the rear sheeting has an advantage in that you get up to terminal speed quicker than centre sheeting in both my fed five and mini.The average is higher but max speeds are slightly lower.
On a 15 to 20 mph day the centre sheeting gives an overall gps average speed ,and max speed higher than rear.

I believe this is because there is no doubt that rear sheeting , in good wind and gusts ,causes the weight to progressively come off the rear windward wheel to the point where hiking begins. In both my 5 and mini this causes a slight tendency for the yacht to head up wind,and to correct that I need to steer slightly downwind .Therefore the rear and front wheels are now fighting each other and must cause an increase in drag .Both my 5 and mini have a y frame with longish axles so this may not be the case with a T with shorter axles since the wheels may stay in alignment .

Watching the sail with centre sheet you can see the sail automatically adjusting to gusts without the need to sheet in or out to get the best trim. With rear the sail tends to remain where ever you have trimmed it to ,meaning you are constantly altering the sheet to suit the wind changes ,that takes time and judgement .Get it wrong and you loose speed.

As an aside a guy from a local club(International competitor ) tells me that in the UK the regs for the mini state that you have to have one pulley behind the riders head so eliminating centre sheeting.(not sure if he said both sport and spirit builds). I have always been suspicious of regs that prevent certain configurations to level up the playing field, because I suspect that they are to prevent a rider from gaining an advantage . Same for distance from front wheel to mast base.
So maybe others have found an advantage with centre sheeting . All good fun.
Fair winds to all 4 or 5 bf please

huru from the guru all my yachts are centre sheeted now BUT I have the sheeting point at about 2/3 to 3/4 back on the boom and a boom that doesn't have a rowlock. since I'm a flimsy half chook in weight I need the rig to flex in the gusts to stay on the ground so my chassis's are designed to flex at the base of the mast step and not through the mast. i have a sheeting set uo so that the sheeting is above my stomach not between my legs, which would be too far forward. if i can work out how to get pics from phone to computer i well send pics next time Im rigged

hi L Y be interested to see how you have the base and rigging, obviously a good compromise between rear and centre,get the best of both systems . With my fed five I can get the center sheeting well back but with mini is is probably just forwards of the centre on the boom,since the bottom pulley is between my legs.I can slide the boom fitting back to about 3/4 but all the force is then pulled forwards,and it does add significantly to the hand pressure needed since it is not in the ideal line of straight up and down . cheers

Select to expand quote

kennatt said..
hi L Y be interested to see how you have the base and rigging, obviously a good compromise between rear and centre,get the best of both systems . With my fed five I can get the center sheeting well back but with mini is is probably just forwards of the centre on the boom,since the bottom pulley is between my legs.I can slide the boom fitting back to about 3/4 but all the force is then pulled forwards,and it does add significantly to the hand pressure needed since it is not in the ideal line of straight up and down . cheers

sorry I don't have any pics these days . will be rigging up in a few months time for race season so I will get pics then