Finally!! The new MKII rig
The idea of a new rig for the boat had been running around in my head ever since we developed the new self-depowering rig for the Byte which we called the CII. That rig dramatically changed the weight range of sailor that could handle the Byte and in a much broader range of wind conditions. I was also very much aware of the fact that the weight range sailing the Megabyte is not the profile of the optimum race-weight that the boat was designed for. It is much closer to the 165 - 185 lb range than the intended 190 - 220 lbs. I was reasonably certain, after the work on the Byte, that I could parallel that development and provide a rig that would make it easier for the lighter sailor to be competitive in heavy air but, at the same, not penalize the heavier sailor. That may sound like a contradiction but it isn't if you realize that the sail area is about 10% larger than the present sail but much more easily depowered. The heavier person simply does not depower to the same extent and can tap into the power of the extra roach even though that leech will always have some twist and never be as tight as the present sail, (see picture of me testing below). However, it still wasn't clear that there would be any real benefit to the Class, even if everybody changed, if it did not bring any new numbers into the Class.
The final impetus came about in a most unexpected way. We were at a boat show with the Megabyte, Byte CII and the 29er, all of which we build. Our Distributor and a few of his Dealers pointed out that the Megabyte with its present rig, when viewed against the other two skiff-like rigs, looked like a pre World War 2 boat! When viewed from down the aisle, they had a point! Their area is one with only a couple of boats but with a huge potential and their customers are looking for something they would like to think of as a modern day boat. "If I am going to change from my Laser then, at the very least, I want a modern, up-to-date boat with a state of the art rig". There are countless such areas, and sailors, in North America many of whom echo these sentiments to us on enquiries.
The first step was to give Ian MacDiarmid, the Australian sailmaker who did the design of the 29er and the CII, a set of preliminary dimensions of luff curve, foot and hoist and to get a first prototype sail to Canada. We rigged up a standard Megabyte lower with one of the early, stiff, Byte CII upper mast section prototypes and tried out the sail for the first time in West Palm Beach.
As you can see in the pictures above and at left, the boom was too high and this made it almost impossible to position the end of the boom over the corner of the cockpit without using so much main sheet tension that the sail either flattened completely in lighter air or heeled the boat excessively in a breeze so that the traveller would have to be dropped and the boat lose it's ability to point. The CII upper mast was also too soft and it started depowering much too soon. Even using the lowest possible sheet tension by carrying the traveller well up to weather, see pictures, one can see that the top of the sail is already flattening out and falling off because of the soft mast and any more tension would flatten it completely.
A second prototype sail was built, a much stiffer top section put on the mast and the luff round on the sail reduced slightly. We did not add to the leech length to lower the clew but rather dropped the hoist down, took some luff length off the tack and fixed the tack to the gooseneck, adding a Cunningham eye about 8" above the tack. This brought the boom level with the water.
Here I am in Montreal testing the set-up of the 2nd prototype rig to verify the sail shape, mast fit and mast stiffness so that we could produce a final sail to do two-boat testing. We made some further minor changes to the sail and decided on further stiffening of the upper mast above the joint with the lower as it was still tending to hinge a bit and the curve was not completely smooth in the area between the second and third battens down from the top. The new sail was a definite improvement on the second prototype and we were very happy with its match to the mast although the mast still needed tweaking in the area above the joint and this was done. Top sections and sails (made by Neil Pryde) are either in stock or in production and we have decided to call it the MkII rig.
We then set about trying to quantify the MkII versus the standard sail and here are our conclusions.
1. A 210 lb sailor is always going to beat 170 lbs in heavy air, regardless of who sails what rig.
2. However, the lighter sailor in the MkII will have a much easier time holding the boat flat and will be a lot closer at the top mark than had he been sailing the standard rig. He will also be noticeably less tired.
3. In 12 kts, when neither sail is really being de-powered, there is not a lot in it upwind but offwind, the MkII is faster - which you would expect because of the larger sail area.
4. In light to medium air (8 – 10 kts) the MkII is faster upwind, regardless of what weight is sailing which rig and the same holds true offwind except more so when a lighter person is in the MkII. Not only is the sail larger, it is easier to get more twist in the MkII sail when running due to the pressure on the large roach and in these conditions, unequivocally, the more you twist, the faster you go!
5. In the light 5-knot range, the MkII is a quantum level faster than the standard rig upwind because of the ability, using ONLY the Cunningham, to bend the mast, open the leech and completely unstall the leech of the sail. (This will be addressed shortly in the sailing and tuning guide).The question we are asked over and over is “Are you dumbing down the boat so a lightweight can sail it when I bought it because it matched my weight?” The answer is in the first paragraph – there is more than enough power still in the rig and, at 210 lbs, I am able to power up either rig to match my weight. However, the most noticeable thing as the wind comes up is the smoothness with which you go through the gusts. Even in the heaviest shots you may need to drop the traveller momentarily but changing mainsheet tension is seldom necessary as the topmast automatically depowers to take you through the puff.
The picture below taken from the weather side is of Kai Bjorn, at 245 lbs, sailing the boat without any Cunningham, fully powered up, and he is on the rail, semi-hiked, in 6 knots!
The picture taken from leeward is in 8 knots and now he is hiked. The last picture shows the rig downwind in 4 - 5 knots with lots of twist.