Mast Bend

[Chuck Hughes]

Besides what is written in the owner's manual, how much mast bend (not rake) do you actually have in your mast, without using a backstay adjuster? I've recently tensioned my shrouds and I'm seeing about 4-5" bend between the upper and lower shrouds. It seems too much.

Chuck Hughes
1999 26X
Riverside, CA

P.S. As an east-coast transplant, I really appreciated today's 80 degree sail.

[Timm Miller]

4-5 is a bit excessive for a Mac....2-3 would be more in line. Use your halyard to give you basic idea of how much bend there is on your mast by placing the end at the base of the mast and then determine how far away from the mast the halyard is. There is nothing carved in stone but 2-3 works well for me....on the "right coast"

[Steve K]

Timm's numbers are just right here. IMHO.

Mast static pre-bend is directly related to the luff curve of your particular main sail. In general, if your main seems always too flat, the mast bend could be excessive for that sail. If the main seems too baggy, the opposite is true. (If we are talking about a mainsl that's in good shape and not blown out). Still, four inches of static bend may be okay for the Mac mast section, but five is starting to push it a little too much, if you ask me.

[Duane Dunn, Allegro]

O boy, we're really worried what you clowns think.

Maybe if your site could come close to the quality of this one your comments could mean something.

Your site: 19 registered users
This site: 301 registered users.
Your site: 675 topics (since who knows when)
This site: 1929 topics (since January 2004)

Your site is full of fake names, cute funny avatars.

This site if full of real people helping others enjoy sailing.

And even better, our boats get us out on the water just as well or better than you boats without becoming holes in the water you pour money into.

We'll see you at the next anchorage, once your slow boat gets there.

[Duane Dunn, Allegro]

Funny, I copied my numbers right off the screen on a visit to their site, and poof, now the numbers have exploded. It's all just a data file, you can make it say anything you want.

[Frank C]

Funny, I copied my numbers right off the screen on a visit to their site, and poof, now the numbers have exploded. It's all just a data file, you can make it say anything you want.

Duane, it displays a hint of inferiority complex behind all of that "sailing anarchy" doesn't it? Suppose a little "puffery" was needed to go along with the "blow-hard?"

Bull Gator ... you would look like a little prick. Kinda like you do here. Are you so arrogant ... would rather these guys were learning the art of sailing on their boats rather than looking for ways to put a bigger engine on them! ... Now go to your room! And don't come out until you've had a long thought about your manners young man!

Most other sites display far, far from the genteel yachting discussions that I appreciate among our membership, If we're a little bit novice, so-be-it, we're still a little bit rock-n-roll, too! Nonetheless, Schock's (welcomed) reprimand to the new "junior" member above was probably in language best understood by a juvenile.

Furthermore, Tripp-gal's been exceedingly polite and helpful, for which I (and others, I'm sure) are quite grateful. Thanks Schock, and Dee, I'd be pleased to give a ride on SF Bay anytime. My personal-best so far (with motor-up ) was close-reaching @ 7+ knots in ~18 kn winds, three different days, but I'm pretty sure you could help to improve that.

And finally, Schock, there's really nothing wrong with a bigger motor. It's quite functional, permitting more flexible enjoyment of variable weather conditions, plus it adds a good margin of safety for the novice sailor (besides, many, many women admit that 'size does matter").

[Frank C]

Frank C:
I agree that size matters! My MAST is 41' long! Hear that ladies?? I'm not trying to hold the engine thing against you guys! It's just that the BIG engine is the single biggest cause of the scorn that is directed towards the Macgregors! Sailing purists believe that an engine is a necessary evil that is best left turned off ...

Hey Schock,
Understand completely. No arguments here, but some observations may be illuminating.

Even in dedicated sailing rags, you'll often read of a cruising couple who spent their 3 or 4 vacation days on the prop - you usually read of a few hours under sail. And we all can see that 80% of of sailboats rarely leave the slip. Just a guess, but I'd bet, of those 20% sailboats that left the slip ... most of their hours underway, are motoring, not sailing. By contrast, I'd bet about two-thirds of my boating hours are under sail (though perhaps only 20% of water miles). Roger Macgregor is nobody's dummy ... he saw that light and marketed 5,000 boats in 8 years.

My 26X was affordable, even with a big motor. The boat is stored 3 miles down-channel from SF Bay to save costs. A few sailors tack that channel in 5-10 kn winds, 200 yds to port, 200 yds to stbd, all the way to the Bay. I'd much rather shoot the channel (plus another wind-shadowed 3 miles to center-Bay), and enjoy San Francisco's steady 18-20 knots. Even dragging 335# of motor and 12 gallons of gas, the 26X can take me upwind at 7 kn. under jib and reefed main (when I get it right). I need to wear goggles to keep salt off my glasses, and stretch the rig like a violin, keep the main flat, keep the heel under 25 degrees, balance precisely or it rounds up like a devil .... what a rush!

I'd die of boredom if I had to sail 2 hours just to get there (~ 6 miles @ 2kn. VMG ...) another 2+ hours on the run home, plus another 2+ hours prep time and maintenance afterwards ... my 3 hours at center-Bay costs over 10 hours overall. Not everybody can afford to invest the money it takes to support a fast sailboat, much less invest the time it takes to remain pure (kinda like horse racing and polo ). At risk of sounding snobbish, many sailing purists are snobs. I very much appreciate seeing your opinion around here. Thanks.

[Dimitri-2000X-Tampa]

Shock, you should mention what location you are at and I'll bet someone would invite you along for a sail. I rarely get to go out with another "sailor" as I'm usually single handing my boat, even with 6 people on board, so I always like to learn other perspectives from experienced folks.

Frank, I'm curious what "getting it right" means with going upwind at 7kn. I presume that you had your reefed main as flat as a pancake and I doubt you could have attained that with a reefed genoa as that still won't get too flat. But I'm curious about your CB, all the way down or half way down? Were you sheeted to the windward of centerline? And how big were the waves and what wind speeds did you have?

I've had my Mac for less than a year so I'm still not very good at sailing upwind on it. Waves definitely slow down the boat more than a heavier boat. The Mac is great at reaching though. I'm not even sure if you need a spinaker on this thing as you can almost sail straight downwind between a broad reach and a run. With the CB up and the flat bottom, it just crabs along like an airplane in a crosswind....something you just can't do on a keel boat. I've gotten about 10-12 degrees off of straight downwind which I'll bet is not much better than an asymetrical spinaker could do...unless of course if the winds were light. Although, most spinakers are much prettier to look at.

[Janusch]

Shock I'm here in Michigan on Lake Saint Clair and if you are every in the area (Port Huron Mac race Maybe) I would be more then glad to take you out for a ride. In my situation our lake is pretty shallow and the first deep water and I use the term deep loosely (7- 9 ft) is about 8 miles from my house. No biggy with the Mac I'm there in 15 - 20 min. I go sailing for an hour or so then 15 -20 min back. So a quick evening out is do able, but in a more tradional sail boat this would take to much time and I would be sailing a lot less. The only other sailboat that may fit my needs and may be acceptable to your group as well is the new telstar 28. Of course I have to convince my wife the 50 grand is worth sailing a couple of knots faster and being able to point a little higher ,

God Speed
Dave

P.S.
Shock I don't think most people are claiming the Mac can do double digit speed sailing up wind. The best I was able to do was 10 knots on a broad reach, but must of the time it is only 6 - 8 knots.

[Frank C]

I can see the appeal of high motoring speed when your boat is located some distance from decent sailing waters, although I thought that was why it was trailerable! ... I guess I am fortunate that I live in an area where I have to motor just long enough to get out of my slip, and I'm sailing! ... so forgive me if I am biased against the "powerboat mentality".

... 7kts upwind for a 26 foot boat sounds to me to be a slight exageration! Don't worry, I won't hold it against you! ... That is why I am skeptical about the performance claims some people are making!

Wow, ST ... too many points for discussion up there, so I've sliced it liberally.

First, I store my boat mast-up on the trailer at Alameda Marina - 6 miles downwind from the action. You can't really trail it anywhere and effectively gain sailing time, because SF Bay is not the friendliest place to put into - the time becomes lost in moving the boat, stepping the mast, etc. Store it nearer to the action and it's vastly more costly - no surprise. One Mac owner finally slipped his boat at Pier 39 for $350 per month. He later sold it and bought a keelboat, since economical storage (a Mac calling card) was no longer available. Candidly, it's pretty clear by looking at those beautiful pix that maybe you ARE spoiled!

I suspect MUCH of your objection to motoring is that diesel ... you haven't had the opportunity to motor quietly on a fuel-injected Suzuki, and no, they don't burn hundreds of gallons of fuel. At my best cruise speed (Suzuki-60 @ 3800 rpms) it's more like 3 gph @ 15 knots.

My Mac may have tacked through 90 w/ my dealer aboard, but I'm more likely to see 100 ... so, as for your reaching index, N/A in a Mac. Regarding speed upwind, Dave Gerr created a modified hull speed formula for semi-displacement boats. If you buy Dave's modified hull speed theory (quoted here on a Potter owners website), you'll recognize that the Mac's flat hull could explain an adjusted hull speed of about 8 knots, largely due to her flat bottom. Not to say she's planing (which is impossible upwind anyhow) but she does not have any rounded hull to hold her within the typical wave pattern.

I've managed a close reach at 7+ knots on three different days on SF Bay. Each time was in whitecaps, heeled at 25*, jib and reefed main. Though it's annoying to your comrades at SA, my GPS reads in mph. On the first two days, it was a fluke to find the groove, and hold 7-to-8 mph for 10 minutes at a time before a roundup. On my third day though, I had it figured out. We managed to hold a port tack for 30 minutes, north-bound from Treasure Is. toward Angel Is, WNW winds of 18-20 kn in 2' chop. The boat felt like it was on rails, and the GPS read 8+ mph for that half-hour, kissing 9 mph a couple of times ... it never touched 7 mph once we gained speed on that tack. Currents on that wide stretch of the Bay are insignificant. You can do the math. That tack was such a rush that I was nearly onto the rocks off Angel Is before noticing, and easing up. I'm no expert, and this is my first sailboat. That's why it took me 3 years of reading and learning and several tries, and just the right conditions.

Also, I've modified my boat some. My mast is forward to 88*, which somewhat impairs pointing, but reduces rounding. The rig is very tight, since I don't need to step the mast each day. I have Garhauer rigid vang @ 12:1, which fractured the gooseneck casting on two of those 3 days. The day of a very long tack, I noticed the boom had a downward arc of ~ 2+ inches, before easing the vang. I have added an 8:1 split backstay and a 4:1 outhaul. I obviously had full ballast, motor disconnected from rudders (so its weight won't contribute to rounding), boom well downhill (not on centerline) and centerboard down at ~70 degrees (needs some aft centerboard to counter rounding). It would be much easier to duplicate with a traveler substituting for some of the excessive vang. I have Harken's small-boat windward sheeting car, but haven't decided how and where to mount it. Since upgrading to a UK 135 Genoa, I've never come close to those stats. The Genny is really a handful on any summer afternoon on SF Bay, but it does make downwind easier.

Several other Mac's have reported similar upwind results - even better - and I've stopped doubting it. I'm sure that you'd be even more competent to repeat my special days than I ... if you could tolerate the other frustrations of the Mac, you'd enjoy one heck of a ride.

[mike]

Store it nearer to the action and it's vastly more costly - no surprise. One Mac owner finally slipped his boat at Pier 39 for $350 per month. He later sold it and bought a keelboat, since economical storage (a Mac calling card) was no longer available.

Wow... almost makes me feel guilty for paying a measly $60/month for my slip!

--Mike

[Dimitri-2000X-Tampa]

I'm not exactly sure what you mean by "crabbing" but I am assuming you are describing lee-way. The reason we have keels is to prevent that! That is why it is only beneficial to lift your centerboard when running near DDW. if you are broad reaching, leeway is wasted boat speed.

Sorry, my airplane pilot lingo. Yes, you are making leeway when crabbing but the bow of the boat is pointing higher than it would be on a keel boat. I'm describing a situation where leeway would be beneficial..ie, your destination is downwind. So, with the CB all the way up, you are actually sliding sideways more than a keelboat to make the leeway, this means you can have the boat/sails configured for a broad reach (and gaining the speed over a dead run) but since you can induce more leeway, your course is more like half way between a broad reach and a run...so, in effect I'm doing what you are suggesting but sailing a straighter course towards a destination that is straight down wind. Of course, if it gets too hot in the boat going downwind, I can fire up the motor and usually go faster than the wind to create a breeze

Hey, thanks for helping me figure out a cool techie term that applies to our Macs....that would be...."induced leeway".

Pictures of your home sailing ground are gorgeous..but you are a bit far from Tampa for me to offer you a ride. So how about it, any Macs in North Vancouver want to take ST for a ride? And now that I know you are a Canadian...how about that Tampa Hockey team....go Lightning!

[Frank C]

Wow... almost makes me feel guilty for paying a measly $60/month for my slip! --Mike

At Alameda Marina (again, 6 mi from SF center-bay), my mastup trailer parking slot is $70/month, and I feel lucky at that! OTOH, I'm soon to move East to help my Mom, near Annapolis. I'll mightily miss this Bay, but the Chesapeake is pretty amazing too.

P.S. Tony D, I'll be in your backyard, Edgewater MD.

[Dimitri-2000X-Tampa]

Some of the fancy marinas around here (like at Tierra Verde Yacht Club for example) will charge you close to $500/month to slip a Mac (or anything else under about 32 feet). I was pretty shocked...a more reasonable rate is about 150-200 for a wet slip.

Frank, I thought you said you keep yours in the water? Or maybe I misunderstood....do you just have it all rigged and trailer it from your storage lot to the ramp with the mast up?

[Frank C]

Frank, I thought you said you keep yours in the water? Or maybe I misunderstood....do you just have it all rigged and trailer it from your storage lot to the ramp with the mast up?

Not in the water, on the trailer with mast up. I tow it about one block to the Grand Ave city ramp, with mast up, no wires to interfere. The ramp is free, and parking is free ... cannot beat it. Also, the marina has a free hoist, but mostly used by the keelboaters who store on trailer.