Please select your home edition
Edition
Kilwell - September

The Byte CII tuning parabola

by Zim Sailing on 21 Apr 2013
Byte CII upwind Zim Sailing http://zimsailing.blogspot.com.au/
The Byte CII World Championship is headed to Newport, Rhode Island this summer, with a host of clinics and regattas leading up to the event. While many of the traditional dinghy classes rely on the vang to induce and maintain mast bend and a flat sail, the Byte CII does not. This makes the boat unique in terms of tuning and sail trim compared to the traditional dinghy classes. To help you train for the Worlds this summer, here is a basic overview of trimming the Byte CII’s sail across different wind ranges.

The Byte CII was specifically designed by Ian Bruce to fit a weight range, as opposed to an age group or gender. Furthermore, the design is conducive to a large weight range (110 lbs. – 160 lbs.). The sail is made of Mylar, instead of Dacron, and is fully battened. When coupled with a tapered, carbon fiber mast, the cunningham carries the load effortlessly to the top of the sail, allowing you to bend the mast and flatten the sail. What this means to sailors coming from other traditional dinghy classes, is that you never use the vang upwind, because doing so will add unnecessary tension to the leech. Other traditional dinghies require this tension, as the vang is the only control that allows you to bend the mast and flatten the sail effectively. This is not the case with the Byte CII.

The golden rule, for tuning a Byte CII upwind, is to achieve the desired sail shape while keeping the boom over the back corner of the boat. When applying cunningham, the mast will bend, and the boom will move outboard. When easing cunningham, the mast will stiffen, and the boom will move inboard. To counter the boom’s movement from the back corner of the boat, you may use either the mainsheet or the traveler, depending on the wind conditions.

The traveler is the second large game changer from the traditional dinghies. The traveler’s role in the Byte CII is to allow you to effectively position the boom over the back corner of the boat with the ideal sail shape for the conditions. In other words, it allows you to effectively control your leech tension for different conditions, via the mainsheet, while keeping your boom in the ideal place for speed and pointing (the leeward rear corner of the boat).

Thus, in the extreme conditions (light and heavy air), where you generally ease the sheet out, you will pull the traveler to windward, pulling the boom back over the corner to maintain your pointing. Thus, the sheet is allowing you to control your leech tension, while the traveler controls the sail’s angle to the wind. In medium air, when you need more power in the sail, and generally would pull tighter on the sail, the traveler drops as far as the centerline of the boat, allowing you to apply just enough tension on the sail to prevent you from spilling much wanted power out of the top.

Because the Byte CII is designed for such a broad weight range, it is important to look at the suggestions below as general guidelines for your level of control upwind. What a 110 lb. sailor does in 15 knots will vary significantly from what a 160 lb. person will do in 15 knots.

Light Air

You will sail with no cunningham (or just enough to pull the horizontal creases out of the sail), will pull the cunningham far to windward, and will ease the sheet to the corner of the boat. Your sail will look relatively full, and pulling the traveler to windward will give you more room to ease the sheet to the corner and open the leech. The tell-tale on your top batten should look like it is trying to go forward 50% of the time, and should fly straight back the other 50% of the time (50/50 rule).

Medium Air

As you are fully powered up and under control (butt over the rail or light hiking), you should set the traveler more towards the center of the boat. You will pull the Cunningham just to the point where you have no creases in the sail. This will move the boom outboard, and you will compensate by trimming the sail to the corner of the boat. The 50/50 rule applies here as well.

Medium Heavy Air

As the Byte CII is a small and physical boat, there is a wind range, where if you hike hard enough, you may want to continue to keep some power in the sail. For the stronger and heavier sailors, I find this may go as high 15 knots or so. In this wind range, you will have the cunningham maxed out, the traveler center lined, and the main trimmed to the corner. If the boat is flat, and you have no helm, this setup will give you tremendous height and power. This will ONLY work if you are hiking hard, and have no helm. The instant you are no longer able to maintain a neutral helm, you should start moving to the heavy air setup. This will happen much earlier if you are sailing in waves and later in flat water.

Heavy Air

As you get to the point where hiking is no longer enough, the Byte CII gives you another setup to keep the lightweights in the game. Once the cunningham is maxed out, and you start dumping the sail to keep the boat flat, start to move the traveler back up to windward. This allows you to dump the sail to the point where you are under control, while keeping the sail in the corner of the boat to maintain your pointing. Without having to use the vang, you are able to do this without applying any tension to your leech, making depowering easy and effective.

The Parabola

Light – Traveler up; sail out; cunningham off or variable
Medium – Traveler down; sail in; cunningham variable
Medium Heavy – Traveler down; sail in; cunningham strapped
Heavy – Traveler up; sail out; cunningham Zim Sailing
T Clewring One DesignBarz Optics - FloatersNaiad/Oracle Supplier

Related Articles

America's Cup - Arbitration Panel Hearing over Kiwi Qualifier for July
ACEA CEO, Russell Coutts has confirmed that the Arbitration Panel will hold its first Hearing in July. In a yet to be published interview in Sail-World, America’s Cup Events Authority CEO, Russell Coutts has confirmed that the Arbitration Panel will hold its first Hearing in July. This is the first official indication that the three person Arbitration Panel had even been formed, however Sail-World’s sources indicated that it had been empanelled since last January, possibly earlier.
Posted on 27 May
Rio 2016 - The Qualification Games - Part 2
Yachting NZ's refusal to nominate in three classes won in the first round of 2016 Olympic Qualification is unprecedented Yachting New Zealand's refusal to nominate in three classes won in the first round of 2016 Olympic Qualification is without precedent. Subject to Appeal, the Kiwis have signaled that they will reject 30% of the positions gained in the ISAF World Sailing Championships in Santander in 2014.
Posted on 22 May
Gladwell's Line - World Sailing changes tack after IOC windshift
Over the past year, we've given the International Sailing Federation (now re-badged as World Sailing) a bit of stick Over the past year, we've given the International Sailing Federation (now re-badged as World Sailing) a bit of stick. Every blow well earned over issues such as the pollution at Rio, the Israeli exclusion abomination plus a few more. But now World Sailing is getting it right.
Posted on 21 May
Rio 2016 - The Qualification Games - Part 1
Antipodean selection shenanigans aside, the Qualification system for the Rio Olympics appears to be achieving its goals Antipodean selection shenanigans aside, the Qualification system for the Rio Olympics appears to be achieving goals set in the Olympic Commission report of 2010. Around 64 countries are expected to be represented in Rio de Janeiro in August. That is a slight increase on Qingdao and Weymouth, but more importantly a full regional qualification system is now in place
Posted on 19 May
Taming the beast-a conversation with Stuart Meurer of Parker Hannifin
While AC72 cats were fast, they difficult to control, so Oracle partnered with Parker Hannifin to innovate a better way. If you watched videos of the AC72s racing in the 34th America’s Cup (2013), you’re familiar with the mind-boggling speeds that are possible when wingsail-powered catamarans switch from displacement sailing to foiling mode. While foiling is fast, there’s no disguising the platform’s inherent instability. Now, Oracle Team USA has teamed up with Parker Hannifin to innovate a better way.
Posted on 18 May
From foiling Moths to Olympic starting lines-a Q&A with Bora Gulari
Bora Gulari’s is representing the USA at the Rio 2016 Olympics in the Nacra 17 class, along with teammate Louisa Chafee. Bora Gulari (USA) has made a strong name for himself within high-performance sailing circles, with wins at the 2009 and 2013 Moth Worlds. In between, he broke the 30-knort barrier and was the 2009 US SAILING Rolex Yachtsman of the Year. His latest challenge is representing the USA at the Rio 2016 Olympics in the Nacra 17 class as skipper, along with his teammate Louisa Chafee.
Posted on 12 May
Concern for Zika at Rio Olympics is now deadly serious
Alphabet soup is one description that has thus far not been used for either Guanabara Bay, Alphabet soup is one description that has thus far not been used for either Guanabara Bay, or the Rio Olympics. Many others have, and they were apt, but things have changed. So here now we have a situation where one man, Associate Professor Amir Attaran, who does have a more than decent string of letters after his name, is bringing nearly as many facts to bear as references at the article's end
Posted on 12 May
Zhik - The brand born of a notion, not its history
here is probably every reason that ocean rhymes with notion. Zhik’s tagline is officially marketed as Made For Water There is probably every reason that ocean rhymes with notion. Zhik’s tagline has been officially marketed as Made For Water, and this is precisely what the company has done for the last eight years before the succinct and apt strapline came from out of R&D and into mainstream visibility.
Posted on 8 May
Shape of next Volvo Ocean Race revealed at Southern Spars - Part 1
Southern Spars has been confirmed as the supplier of spars for the 2017-18 Volvo Ocean Race. In mid-April, Race Director, Jack Lloyd and Stopover Manager Richard Mason outlined the changes expected for the 40,000nm Race during a tour of Southern Spars 10,000sq metre specialist spar construction facility. A total of up to seven boats is expected to enter, but time is running out for the construction of any new boats.
Posted on 3 May
Sailing in the Olympics beyond 2016 - A double Olympic medalist's view
Bruce Kendall takes a look at what he believes Sailing needs to do to survive beyond the 2016 Olympics. Gold and Bronze medalist and multiple world boardsailing/windsurfer champion, Bruce Kendall takes a look at what he believes Sailing needs to do to survive beyond the 2016 Olympics. A key driver is the signalled intention by the International Olympic Committee to select a basket of events that will be contested.
Posted on 29 Apr