Issue 327 - JULY 2013
CRUNCH TIME
Guy Cribb intuition
TECHNIQUE
86 JULY 2013
Crunch Time! TUNING
Words GUY CRIBB Photos Guy Cribb INtuition
One of the fascinating aspects of windsurfing, like all sailing sports, is how much difference tuning makes. In my days as a professional racer and tester we advanced these skills through trial and error and time on the water, honing our development process to the most scientific approach we could find, a challenge considering we were dealing with so many uncertainties like gusts and chop. To be able to share these subtleties with my guests is an absolute pleasure and YES it does make a big difference to tweak your gear, even though there are so many fundamental technique skills to acquire, tuning is a vital and even enjoyable skill that gives you a great base to progress your technique from. This month we’re looking at THE most important tuning tip - positioning your harness lines. When they are in the right place it’s easier to hook in, you can sail using minimal energy, plane earlier, reach higher speeds in control and handle a much wider wind range for your sail. You can even enter manoeuvres more smoothly, like gybing, due to the significantly improved control in approach. If your harness lines are in the wrong place all sorts of carnage ensues - spin-out, fatigue, catapults, all of which can be attributed to poor harness line position, so this feature is vital reading...
WINDSURF MAGAZINE
87
Guy Cribb intuition
R
ecently, while rescuing one of my guests that had a snapped downhaul line and thus total loss of downhaul tension. The sail was atrocious and sent me time travelling back two or more decades to the pre-downhaul Jurassic era - where it was almost impossible to windsurf. What saved me was that the harness lines were in the right place, so despite it feeling like a wrestling match with a gorilla, I was able to feel like I was in a front row seat, rather than actually in the ring with the beast. If my lines had been in the wrong place, I would’ve been torn to pieces! Until that day I had held correct downhaul tension on par with correct harness line position as the two most important tuning features, by far, but that experience changed it - correct harness line position is THE most important tuning feature to give you ultimate control, since I have had far worse experiences trying to sail rigs with correct downhaul, but incorrect harness line position.
iment yielded a remarkably quick conclusion. After only studying a handful of the photos it became immediately apparent there was a constant, and not just any old constant, this one was really simple. Conclusion All the top professional windsurfers back harness line position was one third of the way down their boom, give or take a few millimetres! So simple! Result Like most good ideas it all seems so simple now, but to come up with a device that measures your harness line position accurately every time, no matter how long your boom is or where the pull comes from in your sail, that doesn’t require a degree in maths, has astounded many a windsurfer – including plenty of world champions who’ve been bemused at its accuracy!
Sweet Spot
The Cribb Sheet is a tuning guide covering all aspects of rigging and tuning, that is made of plastic to handle the trauma of being treated roughly on the beach and sea. The Cribb Sheet has a piece of elastic that no matter how long it stretches, a marker remains exactly on one third/ 33% to measure your back harness line position accurately. You could make your own harness line positioning system of course using this method, or buy a Cribb Sheet with all the other tuning tips printed on it too, at guycribb.com/shop (yes due to the fact this is a product that involves printing, assembly, manufacturing, postage etc, sorry but there is a charge!) Worldwide shipping included. A mega plug I know but the thing works so is worth publishing! To get important messages across in coaching I find it is better to eliminate the variables and ‘what ifs’ by really breaking things down to establish the Core Skills – the absolute truths. Believing in these truths gives a solid foundation to build your skills on. In windsurfing having a fixed position for the harness lines achieves two things: 1. Your lines are in the correct place so your windsurfing improves. 2. By fixing this constant it is easy to experiment confidentially with other skills, knowing that if things are going wrong, it must be down to your technique or tactics, not your tuning.
Many years ago I concluded there must be a sweet spot to position the harness lines due to the fact that I could jump onto any other professional’s windsurfing gear and their lines would be in exactly the right place for me/exactly the same place as mine, so I set about trying to establish where that position was. Also, when jumping onto amateur’s, gear I would immediately feel the drawbacks of their poorly positioned lines. But how could I replicate the sweet spot the pros always found and share that information with others accurately, when there are so many different booms lengths and sail designs with a more forward or backhand feel? I knew there must be a scientific method, so I used the old adage - create a result and then find the theory! The result, which I published in windsurfing’s scientific journal ‘Windsurf Magazine’, nearly ten years ago, has been well documented and caused some debate, but most importantly has enthused and developed thousands of windsurfers to progress by eliminating the uncertainty of the most fundamental tuning tip of all.
The Voyage of Discovery Aim Knowing there was a sweet spot was the difficult thing. This came from a few decades of professional windsurfing (i.e., beach-bumming around the world, having fun at competitions and being paid to test windsurfing gear.) Method Establishing the position was surprisingly easy. I analysed a gazillion photos of professional windsurfers in action, measuring their boom length and their harness line positions in search of a commonality - basic data processing that in this exper-
Front harness line position Your front harness line position varies mostly depending on how much power you have in your sail. Generally racers have the widest spread and freestylers the narrowest spread. The narrower the spread the more feedback/information you get from your sail because it’s more sensitive. The wider the spread the more stable the rig is, giving you improved control. Average spreads: Freestyle sailors generally use small sails with little power and big, early planing boards. Their lines are very close together (approx. zero to 3 cm spread)
Racing
Wavesailing
The Cribb Sheet
to make the sail extra sensitive and give the rider the feedback they need about how much or little power there is. Wave sailors have their lines at about a fist apart 9-12 cm spread to combine a bit of control with lots of information. Freeriders should have their lines about 10-14 cm apart to combine good control with a little information. Racers use such big engines (sails) they need little information about how much power there is - they just know there’s loads of raw power all the time - so they have a wide spread as they’re purely looking for control.
Freestyling
Measure the harness line positions for yourself and find the commonality between these different professional disciplines of our sport. All windsurfers should follow this guideline too, whether total beginner, freerider or aspiring professional
88
JULY 2013
Fact or Fiction
One-Handed
On average for every square metre of sail size you go up or down expect to move your lines by about 5 to 7 cm back or forth. Bigger sails = longer boom = lines move back. Race sails generally have the longest boom lengths relative to sail size and freestyle sails the shortest (at least for the last decade). In ancient times people believed in all sorts of fairy tales, like the world was made in seven days, the Earth was flat, harness lines could be positioned by counting your hands down the boom etc - so a 4m sail was four hands back, a 5m sail five hands back, a 6m was 6 hands back etc. What kind of quackery was that all about? Fortunately in the modern world you can position your lines correctly, leave the horoscopes to the kite surfers and apply science to your sport! Degree of change between boom heights. If you’ve been following this series you’ll have learned in the ‘Double Shot’ feature (available for download from guycribb.com) that the boom length changes depending how high your boom is in the cut out. The disparity between the top and bottom of the cut-out is 4cm in boom length. In terms of using your Cribb Sheet, if your boom is in the bottom half of the cut out, your lines should be up to 14mm further forwards than the Cribb Sheet position. In short, if you’re short, position them fractionally further forwards. Degrees of change between outhaul adjustments. Since we only adjust our outhaul by max of 30mm from one extreme to the other your back harness line should only adjust by around 10mm/1cm - which is not worth fussing over.
A good test to get used to the lines in the right place is to let go with your back hand - you should be able to sail for ages like this, taking all the rigs power through your harness. If you can easily let go with your front hand, this is a sure sign your lines are too far forwards. On occasion you’ll see pro’s letting go with their front hand for example to celebrate a victory waving to the camera, but in these situations normally their back hand will have moved well forwards, often in front of the harness lines to enable them to let go with their front hand - as this kind of behaviour is not natural. If you are really comfortable letting go with your front hand, it is a sign that you are only well tuned for sailing slowly, and probably have issues with spin out when its windy or choppy. (See last months ‘Fins’ article at guycribb.com/magazine PDFs for more info on spin-out)
Where to get a Cribb Sheet? Please purchase a Cribb Sheet from guycribb.com/shop. Will I be able to retire from sales of the Cribb Sheet? NO! But I will be happy knowing the product is an enormous help to the windsurfing public and you’ll be happy that the most upsetting of all tuning issues is easily resolvable.
Does the Cribb Sheet work on all sails? The Cribb Sheet is positioning your back harness line one third of the way back down the boom. This is largely because this is the best way to keep your boom in line with the board/ sheeted in/full revs/sail closed (whatever you want to call it that ensures the sail is parallel to the centre line of the board for maximum efficiency.) So regardless of how the sail pulls (more from the front or more from the back) and even partially regardless of whether the sail has a boom ‘cut-out’ (shorter boom / longer main batten (see ‘Race’ image) the Cribb Sheet is primarily ensuring the boom is in line with the board. Shorter booms/ boom cut-outs (see ‘Race’ image) Many modern sails have a much shorter boom length than the ‘chord’ (width) of the sail. Use your Cribb Sheet in the normal way to establish your harness line position as this is mostly due to boom length not sail chord. Then position the back harness line about 2cm further back to compensate for the disparity of sail chord (not the most scientific approach this time because when a sail extends beyond the boom it performs in a different way – that I don’t have room to explain here!) If you are using a sail outside of the 4 to 8m range then the Cribb Sheet is no longer accurate – in this case use the lines slightly further forwards than the recommend position.
Die Hards… Old habits die hard. Some of my guests who’ve been windsurfing for years with the lines too far forwards find it a bit of a challenge to break their old habit. Some find the correct harness line position is a bit further back than they’re used to. Newcomers to INtuition only ever learn the right way so rapidly progress through the sport with no bad habits! If you notice a large pull on your front arm with the lines further back, the chances are its only when you’re underpowered – which I think is fine – because it’s better to have a bit too much pull when you’re underpowered, rather than too much pull in your back hand when you’re overpowered (which is the alternative.) Adjusting your stance to suit the harness line position, rather than adjusting your lines to suit your stance position is the best solution to ensure your fastest progression.
Guy Cribb INtuition
Britain’s Professional Windsurfing Coach
Guy runs windsurfing coaching courses all over the world in
Hawaii, Australia, Brazil, the Red Sea, Texas, Greece, Ireland and Morocco guaranteeing his guests have the most wind and the best time on and off the
Using your Cribb Sheet. Instructions on the sheet or follow these images:
1. Thread the Cribb Sheet elastic through the clew hole.
2. Hold the knot at the front of the mast below the boom.
3. Line up the back harness line with the marker point.
4. The marker should be at the back of the back harness line.
Summary The correct harness line position: = S ail trimmed in line with the board = good downforce onto the mast foot/mastfoot pressure – keeping the board going straight and controlled. =M ast further forwards, increasing mast foot pressure, control, early planing etc. = L ess or zero pressure on back hand, meaning the rig has constant power rather than surges of power on and off the mastfoot that are the cause of spin-out and often catapults. If your lines are too far forwards fundamental disasters occur: =D epowering/’sheeting out’/opening the sail/losing revs – which cause a lack of board control and directional stability – often resulting in catapults or spin out. = L eaning the mast back/raking the mast back/causing a loss of mastfoot pressure and making gybing much harder. = Slower board speeds. = Fatigue. Please check out guycribb.com for lots of downloadable technique and especially focus on the Stance features to help you develop the skills required to get comfortable with the new harness line positions. With many thanks for reading, Louis Restaurant, Kattavia, Prasonisi, Greece- INtuition Freeride course, June 2013...
water and ensuring their fastest progression. Nothing is left to chance because at INtuition, hope is not a strategy ;-)
INtuition.
Riding the world by storm. Copyright Guy Cribb 2013 www.guycribb.com Like Guy Cribb Windsurfing INtuition on Facebook?
WINDSURF MAGAZINE
89