Standing rigging and weather helm on port tack.

[Greensleeves29]

Hi, I would be grateful for any advice on this problem i have.

I experience some very bad weather helm, but it is only apparent on a port tack. It is so severe that in winds above 15 knots i do not sail, as the tiller can be completely over to weather.
On a starboard tack the boat has an almost neutral helm.

I have tried letting the main out until it luffs, reefing the main, smaller headsail, more halyard tension, more outhaul, etc.. all with no difference.
It's a 29ft boat, long keel, masthead rig, the sails are ok.


I think it must be the rigging, but i would like to know if a poorly set up rig could cause such a strong asymmetric effect? Or should i be looking elsewhere?

[StuM]

Unequal tension in your shrouds resulting in the mast bending and/or leaning to one side more than the other can do that.

[Captn_Black]

Well if it is only on one tack then yes, it is probably the rigging rather than the sails. Has the problem always existed? If the problem is that bad you should be able to notice the uneven tension by hand. If not, perhaps the mast is about to break? Did you check the full length?
Maybe it's bent spreaders, uneven tension on upper shrouds. You need to check every part of the standing rigging.

[thomm225]

First, larger jib not smaller.

Second are the jib cars equal on both sides?

Is the mast centered? (port/starboard)

[Greensleeves29]

It has been like this since i bought the boat. The shroud tensions seem similar.

I realise it did not make sense to use a small jib, but i thought it was worth trying.
I have played around with the jib cars and i did not notice much effect on the helm.


I sometimes have to re tighten the jib halyard on the port tack, could this indicate that the mast is bending?

I am just surprised by how stark the difference is. Like night and day.

[Sailmonkey]

Is the mast square to the boat?

Or the boat may be asymmetric requiring the mast to be rigged more to port or starboard.

[Captn_Black]

Originally Posted by Greensleeves29

It has been like this since i bought the boat. The shroud tensions seem similar.

I realise it did not make sense to use a small jib, but i thought it was worth trying.
I have played around with the jib cars and i did not notice much effect on the helm.


I sometimes have to re tighten the jib halyard on the port tack, could this indicate that the mast is bending?

I am just surprised by how stark the difference is. Like night and day.

Yea, I doubt the problem is the jib cars with such a big difference as you're experiencing. The mast could not be aligned, but if that is the case and the stays are correctly tensioned, then there would have to be a more serious problem as well. Ofc you can check to see if the stays are tensioned properly by hand, but it may also be worth your while to borrow a stay tension gauge from someone. All this is assuming that you don't want to seek advice from a rigger.

[Captn_Black]

There could be a soft spot on your coachroof causing it to bend differently on each tack. Assuming that it is deck stepped. Well, if it is keel stepped then there could also be a problem with the hull, but that is a potentially deadly problem, if the hull is weakened near the keel, so you should not sail far from port or at all if you suspect that.

[SVHarmonie]

It does depend on the boat, and lots of details, but on many boats it is heeling that drives weather helm even more than sail balance. Does the boat heel equally on the two tacks?

If you are going to try to tune the rig yourself, read this book Illustrated Sail and Rig Tuning. Follow the process FROM THE BEGINNING and do not skip any steps.

I see a lot of people talk about "unequal rig tension" here. That is not correct. Unless things are WILDLY out of whack and you mast is bent like a pretzle, the two cap shrouds (for example) pull against each other, so in the absence of wind pressure, the tension in the two shrouds HAVE to be the same! It's the LENGTH that is wrong. Tension tells you absolutely nothing about how the rig is centered.

This is how many people go wrong rigging with using a tension gauge. Pulling one side to full tension then going to tighten the other side will always result in an off center rig.

[StuM]

Originally Posted by Captn_Black

Yea, I doubt the problem is the jib cars with such a big difference as you're experiencing. The mast could not be aligned, but if that is the case and the stays are correctly tensioned, then there would have to be a more serious problem as well. Ofc you can check to see if the stays are tensioned properly by hand, but it may also be worth your while to borrow a stay tension gauge from someone. All this is assuming that you don't want to seek advice from a rigger.

Just sayin': Stays are fore and aft rigging.

[Captn_Black]

Originally Posted by StuM

Just sayin': Stays are fore and aft rigging.

My apologies professor - "standing rigging" :P
I'm not the only one that refers to them collectively as stays, though of course it was not helpful of me in this context.

[StuM]

Originally Posted by SVHarmonie

I see a lot of people talk about "unequal rig tension" here. That is not correct. Unless things are WILDLY out of whack and you mast is bent like a pretzle, the two cap shrouds (for example) pull against each other, so in the absence of wind pressure, the tension in the two shrouds HAVE to be the same! It's the LENGTH that is wrong. Tension tells you absolutely nothing about how the rig is centered.

You are correct, sort of.

Tension and length are two faces of the same coin.



If the mast is out of true because of different length shrouds, it will lean and/or bend to one side due to gravity which results in more tension on the long shroud and less tension on the short shroud. Obviously when you "tension" your shrouds you are actually changing their length.

[kmacdonald]

I think his rudder is bent or deformed. Sloppy rudder bushings, etc. Seems like too much variance to be rigging alone.

[boatman61]

Best way to check your mast is tie a weight to your spinnaker line and suspend it just above deck level..
Or remove your boom and do the same with your main uphaul.. that way you can check your rake as well.

[Captn_Black]

Perhaps we could be looking at damaged shrouds here? Causing one side to stretch more than the other under tension? Or damage to the hull by way of the chainplates?