68 cm of Rake in a Ten-Meter Mast . . . Way Too Much Rake ?

[JuanCH]

Hi all, today I checked my mast rake and it read 68 cm (my mast is 10 meters high double aft spreaders. I still havent gone sailing but as a starting point is it way too much? What are your thoughts?? Thanks!

[cabo_sailor]

My initial thoughts are that you should contact Laser directly and ask them. As we say "straight from the horse's mouth".

Rich

[JuanCH]

thanks for your interest Cabo but I am talking about a 25 footer, not a Laser dinghy!

[Weyalan]

That sounds like a lot of rake in a relatively short mast (we have less than half that in an 18m mast). But I don't know the boat, nor the mast. I'd suggest contacting a local mast rigger for advice.

[rgscpat]

Is it a racing boat? How is the mast stepped? Are there mast partners? Is the forestay adjustable? How much are the spreaders stepped, if any? Do you have a feel for how "bendy" the mast is? (If you put the mast horizontally with its ends on a couple of sawhorses, how much would the middle sag?) Are the the shroud turnbuckles set up for easy adjustment? How much tension is in the rig? Perhaps pictures would be helpful. Note that for some boats, "tuning guides" are available on the Internet, particularly from some sailmakers.

[cal40john]

Rake determines how much weather or lee helm you will have, and it is different for every boat where the balance point is. As others have said find someone who knows your particular boat. Failing that, sail it and if you have a lot of weather helm it is too much rake.

John

[SimonV]

what sort of boat is it Laser Radial are not 25 foot long.....mono or cat?

If it is the International Laser you are talking about then that rake would be about right as a mid point for tuning.

[cal40john]

Originally Posted by SimonV

what sort of boat is it Laser Radial are not 25 foot long.....mono or cat?

If it is the International Laser you are talking about then that rake would be about right as a mid point for tuning.

The slash means he has 2 boats. He said in the first post a 10 meter mast.

How do you adjust mast rake in a Laser? It has a socket you put the mast in.

John

[Blue Stocking]

OTOH, if this is an iceboat, 68 is about right. Who knows??

[SimonV]

Originally Posted by cal40john

The slash means he has 2 boats. He said in the first post a 10 meter mast.

How do you adjust mast rake in a Laser? It has a socket you put the mast in.

John

By cranking on the boom vang...............

[cal40john]

Originally Posted by SimonV

By cranking on the boom vang...............

OK you got me, I guess you are raking the top of the mast back by bending it with the boom vang.

Most folks talk about raking the mast to change weather helm by changing the length of the forestay. (And on some boats by moving the mast step fore or aft. The Finn comes to mind.)

Mast bend to flatten the main is accomplished by boom vang or backstay on a fractional rig. Or on modern beach cats by pulling on the downhaul.

[psk125]

Cal40John had the right idea. The only way to tell if it's too much rake is to see how it affects the way the boat handles. If she's got tremendous weather helm, so you have to hold the tiller 'way over going upwind just to stay on a straight course, it's too much. You want some weather helm, to help you go to windward, but not too much. To get less rake you can shorten/tighten the forestay (let out the backstay when you do this, if you have one), or move the maststep aft, depending upon how your boat is set up. Too little rake can result in lee helm, which can be dangerous. It tends to make the boat head downwind, which under plain sail can result in excessive heeling and possibly wipeout jybes.
Bending the mast, which you can do by cranking in the backstay or boom vang, helps flatten the sail for stronger winds, along with tightening the downhaul or Cunningham.
FWIW, on a Soling (27' with deck-stepped mast also about 27' long) we routinely carried about 2' (60cm) of rake.

[Cheechako]

Originally Posted by cal40john

Rake determines how much weather or lee helm you will have, and it is different for every boat where the balance point is. As others have said find someone who knows your particular boat. Failing that, sail it and if you have a lot of weather helm it is too much rake.

John

What he said, but that's a LOT of rake.... 27 inches?

[JuanCH]

thank you all, I will try with less rake.