C&C 27 Association Forum

Guest

mast rake and weather helm

My Mark V boat seems to have a "short" backstay which limits my adjustment of the mast rake.  With the backstay extended as far as safely possible, I have about 12" of rake measured at the gooseneck.  The owner's manual seems to suggest 6" as the ideal measurement.  The boat sails well, with a nicely balanced helm, in light to medium-heavy air, but in very heavy air it seems to develop excessive weather helm.  This is in spite of making the usual sail shape and position adjustments for the conditions.  I am thinking of putting some link plates into the backstay to move the masthead forward.  Does anyone else have a similar problem or can make a recommendation on the proper amount of mast rake?
Thanks, Bob England, S/V Heatwave, sail #75

Guest

Re: mast rake and weather helm

I do have a mark V and I do get weather helm with the following contrition. Winds above 16 knots too much sail up. I find with wind this fast I cant sail with main alone and make 6 knots, I do use a GPS for speed and windex  anemometer mounted off the stern for wind speed. If you are not racing why kill the boat.   Kenny

Guest

Re: mast rake and weather helm

Hi Bob
I race my MKV and we carry the #2 up to 20 Knots without too much trouble.  In heavy air I add lots of mast bend to depower the main and lots of cunningham & outhaul to flatten it.  Upwind in a puff I feather the boat to winward a bit, and then the key is to play the traveller and ease it down when weather helm develops.
We have about 8" of rake.

Guest

Re: mast rake and weather helm

If the backstay length is the problem, it is inexpensive to fix.  The "Navlock" or similar brands of swedge-on fittings come in extra long styles so you can cut your stay at the top of your old one and install the new one and actually gain length if you wish.  Adding a link is actually cheaper.  Any competent rigger can do this for you.  Just be sure to retune the whole rig after resetting rake.
Warren Smith
Serendipity