No backstay on the 26M??

[Paul L]

It seems like an easy question. I've used the SEARCH function, but no luck.

Today I raised the mast on my 2005 M for the first time (in my driveway). It seems that the only thing that keeps the M's mast from falling forward is the forward part of the hinge plate (that CAN'T be enough) and/or the boom's topping lift via the main sheet. Having been involved in a few guyed radio tower erections in my day, somehow this just doesn't seem right. If I'm sailing along with no main and a good wind in the genoa, what counters the forward stress on the mast?

Thanks

[Matt19020]

Paul, You are correct there is no backstay on The "M" The spreaders do a pretty good job....However I would read my 2 post on page two of this thread: http://macgregorsailors.com/forum/viewt ... a&start=15
Some people think this is "overkill" but it gives me piece of mind...

[NiceAft]

Paul,

The M has a rotating mast, which would not do so if a back-stay were involved.

You need to define

a good wind in the Genoa

Since you are concerned about a back-stay, you are inferring about a mast collapsing forward. I don't recall ever seeing a post on that. Matt's post represents the posts which I have seen. I just don't remember seeing anything about the mast going forward.

Ray

[Paul L]

Matt, I read your thread, but it seems to deal with reinforcing the furler/forestay.

Yes, I'm wondering where the resistance to the mast falling forward comes from, especially for instance with no mainsail to hold it back, and forward mast pressure from wind in the jib/genoa. Since the M has no backstay, I see only three options:

1) the forward bit of the hinge plate that stops against the deck.

2) The boom topping lift and the mainsheet.

3) The side shroud/stays.

It just feels real iffy to me. But I'm a new sailor and new to Macs.

Thanks

[delevi]

Paul,

The spreaders are swept aft, thus the upper shrouds provide apmple support for mast's forward forces. I have an 05 M and often sail in big winds. I'm on SF Bay. No rig problems. Don't worry. BTW, in big winds, you shouldn't be using a genoa on a Mac. You'll find the boat to be much more tender than a keel boat. In a big blow, you'll be reducing sail rather quickly. Nonetheless, Even with full sails, the rig isn't something to be concerned about, provided it is tuned properly. The boat would be on its side or rounding into the wind long before the rig approaches its limits.

Leon

[Russ]

Yea, the lack of backstay is weird for us traditional sailors. The spreaders are raked aft and provide support for forward pressure. Other sailboats do this now. Don't worry, many M's do just fine sans the backstay. My problem is grabbing the phantom backstay. I have adjusted to this.

You are in Camano Island? MY bro-in-law lives there and we visited there in March when we picked up our M in Seattle. I'm trying to convince him he needs a Mac.

Cheers.

--Russ

[Paul L]

Thanks Leon & Russ for the answer. So I guess it's safe to finish rigging, tightening up the roller furler.

Leon I really enjoyed your youtube video sailing in SFBay winds a few months ago...I think that was you.

Russ...Bozeman eh? Two of our 3 kids were born in Bozeman 25 years ago (yep 10 months apart...something in the water there!). Beautiful place that Galatin valley!

Thanks again,
Paul

[baldbaby2000]

You should be careful about sailing with a genoa and no main sail in heavy wind. The main sail does pull back on the mast and makes up somewhat for the lack of a backstay. There are good and bad things about not having a backstay. I like it because raising the mast is much easier with one less wire to get tangled up.

[bubba]

There are optional running backstays that attaches to the tracks on the sides of the cockpit. The only thing they have to be adjusted constently so the mast can rotate and to make room for the boom when running down wind and a broad reach. The only thing they really do is to straighten the curve in the jib and if raceing it might help some. I have photos

[bubba]

Here is the Running Back-stay photo : http://i293.photobucket.com/albums/mm42 ... 8013-1.jpg and http://i293.photobucket.com/albums/mm42 ... s08014.jpg these are on Blue Water Yacht's boat the 'Black Pearl' to accommodate their 550 sq ft A-spinnaker with extendable bowsprit http://i293.photobucket.com/albums/mm42 ... s08001.jpg . On stock Mac M's these things are not really needed to sail like this http://au.youtube.com/watch?v=PxmDYpj_lo8

[NiceAft]

I am not trying to hijack this thread. I am only informing Bubba that the Black Pearl is no longer owned by BWY. They sold it.

Ray

[bubba]

It was for sale when I took a bunch of photos of all the modfications, for about $50,000.00. Where did it end up? Did you buy it?

[bscott]

I have running backstays on my with the rotating mast. Each stay goes to the stern quarter with its own 4:1 vang.

Yes you do have to ease off the windward vang (the leeward van is NOT hardened) to facilitate a tack and allow the mast to rotate. Then you harden up the new windward vang. On a close reach both vangs are hard and I can tension my forestay for a fine entry. DDW, vangs are eased.

I can get a slight mast bend. When sailing without the main I can feel that the backstays tension themselves---so the mast does want to go forward. The amount of forward movement is controlled by the shrouds. Since I like to have my mast go forward on a beam reach I only have 200/250 Loos and can go from 2* back rake to 2* forward (unrake?).

I agree with Baldbaby that running with a 150 or chute without a main/vang is looking for trouble.

Bob

[delevi]

I've done it without runners, both spinnaker and genoa w/o main. No prob. Then again, I push the envelope a bit.

[Kelly Hanson East]

AIA if I offend but engineering isnt a touchy feely science - its crunching numbers and understanding materials strengths and strains - things that are quantifiable and reduce to hard numbers

Roger has knowledge (decades of experience) in this area and the boat is designed to take the stresses you mention.

You could tie off your topping lift if sailing without main as a safety if it really concerns you, I guess....but breaking through 4 shrouds to tip the mast forward would take a lot of force - Im sure many other things would be breaking first.

Underneath that mast step is a compression pole which is pretty strong in compression (ergo the name) - that deck step is pretty tough and not going to be easily bent forward.