Mast rake, how much?

[SteveLKN]

It seems to me that my boat has a lot of mast rake (approx 12" at the top of flaked mainsail), how much rake does your mast have?

I'd like to start my tuning with a fairly vertical mast but because of the short upper shrouds I can't get it there. But then if I did get the mast fairly vertical I'm afraid my forestay would be so slack that it wouldn't tension with the backstay! Anyway can any of you please tell me how much mast rake you have.

Also I moved my upper shrouds to the forward chain plate just to see what happens. But due to lack of wind haven't been able to sail it yet.

 

[sail sfbay]

I am sure you will get plenty of feedback from the forum. You can also consult your mast manufacturer owner's manual. Mast rake depends are a few factors as I understand: how your sails are cut, mast type and sailing conditions. My in-mast furling mast is raked is about 1 degree and does not have a backstay to adjust the rake while sailing.

This thread and article might be helpful:

Adjust Your Mast Rake for More Speed

Adjust Your Mast Rake for More Speed - On some boats , one can adjust their mast rake.

theewater.sailingacademy.co.za

https://www.qhttps://www.sailmagazine.com/cruising/what-mast-rake-is-all-aboutuantumsails.com/en/resources-and-expertise/articles/what-you-need-to-know-about-rig-tune-performance

 

[Codybear]

From my Hobie days, it's really the length of the forestay that is going to control mast rake. If you lengthen/loosen the shrouds without shortening the forestay, you'll just have a looser rig with the mast slightly forward and leeward while sailing. If you crank on the backstay, then the mast will be mostly leeward while sailing. While only marginal, the more leeward the sail, the more downward the resultant vector is. The new America's Cup boats are trying to sail with the boat healing to windward which will give a slight upward lift by the sail. The AC boats can only heal slightly to windward and certainly not to the extreme of a windsurfer, which can obtain significant lift with the mast cranked to windward.

My rake is around 11.75". Personally, I would keep the uppers aft. Because my uppers were cut about an inch short, I've added Selden 174-103-01 toggles (kindly provided by Selden). This makes it much safer when stepping/dropping the mast; otherwise, I was within a couple of threads of disconnecting to get the rig loose enough. But by my lengthening the uppers by an inch, that did not change my rake. It just means I have more threads on the turnbuckle. The tension ends up the same on my Loos Tension Gauge when I'm finished stepping the mast.

 

[Will Gilmore]

Mast rake depends are a few factors as I understand: how your sails are cut, mast type and sailing conditions.

Very true. There is also a bit of personal preference involved. I like to have rake in my mast.

it's really the length of the forestay that is going to control mast rake.

Yes. The rake is set by the forestay. Tension is set by the backstay, if you have backstays.

The Catalina 275 is a fractional rig. How does the main do tacking past the backstay? If you get too far forward, you may get leach interference. Set the rake how you want it, by the forestay, then tighten the backstay just until you notice a bend in the mast, then back off just until the bend comes out. Perfect. The sail is usually cut so the boom lays horizontal and level.

-Will (Dragonfly)

 

[drewlamparello]

You may find these Diagrams helpful that I got from Catalina/ Seldon... Calls for the uppers to be connected aft

 

[Azure]

Thank you for starting this topic as I would like further answers on rig tuning and mast bend. Looking at the Selden drawings it appears to show two spreaders. Am I misreading the drawings?

 

[drewlamparello]

Thank you for starting this topic as I would like further answers on rig tuning and mast bend. Looking at the Selden drawings it appears to show two spreaders. Am I misreading the drawings?

Selden is lazy in regard to the documentation, I asked that and was told just to ignore the second...

 

[Codybear]

Here I was thinking the "CONV 2019" marked on the second pdf was showing this as a new feature that was going along with the new relocated shrouds. And all this as an attempt by Catalina to justify the word "Sport" in Catalina 275 Sport. It's going to take a lot more than some rig mods for that to happen.