Proof that the M is faster than the X??

[TampaMac]

A few things:

1. I have a new Jib, not a jenny. It is an X jib, which I guess is the same as a M Jib.

2. I have a fully battened mainsail with four battens made by doyle, who I guess makes the stock sail, but this one seems much better made.

3. Doesn't an "M" mainsail have a larger area? Like 10%?

4. The effect of the rotating mast may have been exaggerated a bit. The mast has a longer chord, so would present more drag and turbulense to the airflow when it is not aligned than a X mast would. Hence from a negative to a positive situation when the mast was aligned would tend to exaggerate the effect. But the effect was huge! The non-sailing girl with me immediately commented about what a huge difference it made when I aligned it right.

The boat sails better, period. I would like to get together with someone who has a stock X and see what kind of differences there are in sailing. Granted I'm not a racer, my sailing skills are average at best. Maybe we could switch crews from boat to boat to even out the skill part of the equation some.

[Mark Prouty]

Observations from Inmon Yachts.

The new boat is significantly faster under both power and sail, and quite a bit faster under main alone. We compared two identically rigged and loaded boats, a 26X and the new 26M, both equipped with 50 hp Mercury Bigfoot engines.

At identical rpm settings, the new boat had an advantage of approximately 2 to 3 mph. This advantage held over a wide range of speeds. It held in both calm and choppy water. The big reason for the higher speed on the new boat is the lack of centerboard trunk drag. When we studied the videos of the speed runs, the turbulence from the 26X centerboard trunk was clearly visible, while the new boat offered a really clean water and spray pattern. The old centerboard trunk carried along about 100 lbs of water, the new trunk, with its tighter tolerances, carries virtually none. The 26X, boat, with its flatter bottom, was slowed each time it came down hard off of a wave.

Both boats showed an equal ability to get up on a plane.

Under sail, the differences were striking. In all conditions, the new boat had a major speed advantage. The taller rig, reduction of the drag from the centerboard trunk, and the rotating mast really paid off. I believe that it will prove to be the fastest trailerable boat we have ever built.

The most striking difference in speed was when both boats were sailing with main alone. In typical conditions, when the 26x was sailing with main and jib, it was going about 5.7 mph. When the jib was furled, the speed dropped by 2 mph. With the new boat, when the jib was furled, the speed dropped by only 1 mph, with little change in the balance of the boat.

This means that an owner can go out for a sail and forget the jib, and still get good performance. In high winds, the main alone is an excellent choice. The new boat is less likely to get in irons when tacking with just the main, and if it does, it is far easier to recover. It balances almost as well with the main alone as it does with the main and jib.

Since the front third of the main is now working, and not screwed up by the turbulence of the mast, the thrust is now forward, rather than to the side. The result is more speed and less healing angle. When the mast is properly rotated, the boat comes alive. When the mast is centered, the boat slows measurably.

The 26s rotating mast is similar to the setup used on modern catamarans. We have developed a system (for which we are seeking a patent) that allows conventional spreaders, with upper and lower shrouds, and a mast that rotates to good airflow across the mainsail.

With a conventional non-rotating mast, the mast creates a serious amount of turbulence on the mainsail, making the first third of the sail virtually useless. The deep notch between the mainsail and the mast disturbs the laminar flow of air across the downwind side of the sail and causes the smooth air flow to separate from the sail and disintegrate into a vast field of turbulence. The drawings below show the difference.

Since the first third of the mainsail is not working, the thrust created by the main is almost totally sideways, causing a lot of heeling and less forward thrust. (See the above drawing.)

With the rotating mast, the boat heels less and goes faster.

The mainsail can now be used as the only sail for comfortable effort-free day-sailing. When the wind kicks up, getting rid of the jib and keeping the mainsail retains really good performance, and makes sailing a lot easier.

The mast section is larger (fore and aft) and does not require a backstay. This reduces weight aloft, and reduces windage.

The rotating rig raises and lowers like a non-rotating rig, and requires no attention when sailing. As the boat tacks, the mast automatically adjusts itself to the proper angle without human intervention.

When raising the mast, there is no backstay to tangle up in the rudder system or outboard motor.

The mast is 2 taller, giving a bit more mainsail area and a better looking rig.

Gentlemen,
The M rigging is better.

How much better?
Someone needs to take TampaMac up on this:

I would like to get together with someone who has a stock X and see what kind of differences there are in sailing. Granted I'm not a racer, my sailing skills are average at best. Maybe we could switch crews from boat to boat to even out the skill part of the equation some.

[ken lockhart]

As I said earlier, I owned a 26X at one time and now own a Hunter 26, the Hunter rig is similar to the 26M except for the rotating mast and you tune a B&R rig a little different then a 26X rig. The larger main and small jib with the 26M is easier to handle then a 7/8 or mast head rig because of the smaller head sails required to get more performance. I just won the Mayors Cup Regatta in my Div here in Indy with my Hunter 26. I can point as high as a J-24 or Merit 25 most of the time. This is due to the proper tunning of the mast with no back stay. I have attached a link to a site that explains how to tune a rig without a back stay. Remember, a three legged stool is more staple then one with 4 legs.

http://www.hunterowners.com/ref/br.html

Ken

[RandyMoon]

Has anyone owned a X and moved to a M? What is your impression?

[Frank C]

Has anyone owned a X and moved to a M? What is your impression?

Sure ... Tom S from the PNW, and he's knowledgeable enough to recognize the working differences.

But IMO, no notable, discernable, everyday performance improvements are yet evident. I think some minor modification effort to cure the centerboard drag would level the playing field. Then a set of quality sails on either boat would tell the real difference.



P.S. It's unclear to me how the M-rig qualifies as a freestanding, winged mast - at best, it's a very rough approximation of the rigs described in the excellent article (linked earlier, Freestanding Masts).

[Tom Spohn]

Randy,
I have owned both a '98 X with 150 genny and an '04M with the 100 jib. They are both great boats and I really believe you could choose between them based on your budget and how you feel about the interior. There are a few differences in how they sail however:

1. The M sails fine without a headsail; the X needs the headsail up to balance the boat.
2. The M creates a less turbulent wake when sailing. You can observe both the X and M wakes at 4 or 5 knots and the M will be smoother. I take this to be less resistance. from the rounder aft hull of the M vs. the squarer aft hull of the X.
3. The M performance will not "go to hull" if heeled beyond 15 or 20 degrees as much as the X does. Once again the square corners on the X slows her down when heeled excessively. I'll let others debate what is "excessive" Excessive on my boat is when the Admiral threatens to mutiny. I think both boats do really well in the 10 to 15 degree range with puffs causing a momentary 20 or 25 degrees. Initial stability on the X is better, but the M hardens up pretty well around 10-15 degrees of lean.
4. In our area most X's have the 150 genny and the M's have the jib. This will lead to different strategies when trying to get the most out of them up-wind. You will go faster in the X if you fall off a bit and you can point higher in the M. When going from point "A" to point "B" the best skipper and crew will get there first.
5. The M is significantly more comfortable in rough water. The sharper entry and deadrise really make a difference here, although it is most noticable when motoring. Both boats are lightweight and will bounce around more than a heavy keelboat in the rough stuff. Still I like the M ride a lot more.
6. Off the wind is a toss-up or maybe an advantage to the X with the bigger headsail. Both boats do better on a broad reach with keel up and one rudder up, than they do wing-on-wing.
7. In summary, I believe the M has a slight advantage in sailing over the X, but it is very small and can be easily overcome with skill and experience.

Every year BWY has at their annual rendezvous and event called, "Not quite a Race". All the boats are racing around three buoys, but they are timed and can enter the course at any time. One classic piloted by an old-timer always wins. The X's and M's are sort of a bell shaped curve. I believe the X pilots in general have been sailing their boats a while longer and really know how to squeeze out that extra 1/2 knot and can stay competitive with the M. If you could find two championship crews of equal ability (As Waternwaves would say: "LOL") I think the M would win--unless the X boat painted the hull blue.

[baldbaby2000]

You Yours

The article provides the appropriate information relaying the fact that a non-rotating spar on the wind is awful for generating power and states: The airflow quickly separates off the mast. The article refers to the sail maker being forced to build enough camber into the sail to FOOL the airflow into reattaching.

It makes me wonder if the stock main sail for the 26M is really cut for a rotating mast or does it have excessive camber.

[Tony D-26X_SusieQ]

I bet if we got new "blue" sails and painted the hull blue we would be uncatchable
Say! Can you get that "M" mast in blue too

[DLT]

First, I need to preface this with: Normally, I wouldn't argue with Moe, as that is an activity that doesn't have a high probability of success. Also, I may not be understanding something here. Finally, I don't buy all the hype, either...



If I understand the MacGregor Hype correctly, not only are they saying that the rotating mast makes the boat more effiecient, which might increase heel angle, as Moe suggests. But, they are also trying to make the point that, in being more efficient, the force from the sail is more forward, rather than to the side.

The end result, again according to the hype, is not necessarily more heel angle, as Moe seems to assume, but possibly less...

[Chip Hindes]

All other things being equal, the rotating mast on the M gives it a theoretical performance advantage over the X. All other things are not equal.

You can't cite Roger Mac's marketing BS, highlighted, in color with italics, bold, underlined, in large fonts, as "proof" of anything other than that you know how to use these features.

Extrapolating a quote concerning the performance of a Corsair to the same concerning the Mac is proof of nothing. Besides, to serious racers, a "decisive performance advantage" is a few seconds per mile.

Don't get me wrong. It makes theoretical sense, and I will concede that the rotating mast is probably faster. So's the daggerboard. But you guys apparently want to debate the theory and insist your boats are faster than ours, with no actual proof, until the rest of us are sick of it. I don't pretend to speak for the rest of X owners, but in my case, you already have and I already am.

Be content in your own mind that your boat is faster, or go out there and actually prove it. Otherwise, I'm begging you: give us a break and give it a rest.

A one-on-one boat test, or even several of them, will prove nothing; unless you take special effort to guarantee it, including the skill levels of the skippers, all other things will not be equal. The only proof will be when there are lots of Ms racing lots of Xs, and we will be able to say, on average, it appears the M is faster. Or not. Will that ever happen? Maybe, but not any time soon, until there are a lot more Ms fielded. And you still won't be able to reasonably separate the effects of the rotating mast, centerboard versus daggerboard, larger mainsail, revised hull shape, fixed ballast, etcetera.

And BTW, I'll take odds the 26D will still whip your butts except under power.

[Moe]

DLT, feel free to argue or debate with me anytime. If we were discussing the effect moving the center of lift or center of effort forward has on reducing excessive weather helm, I'd agree that moving it forward, and thus inboard, would be a good thing.

But when it comes to the effect of the fore/aft location of the center of effort on heeling, that's probably much less significant than that of the height and magnitude of the center of effort, the latter of which would probably be the most influential factor with the rotating mast.

--
Moe