Weather helm when beating

[Ged]

Hi
With the boat flat and the jib drawing nicely I get quite a lot of weather helm if I sheet the mizzen anywhere near the centre line. In fact I have to ease it quite a long way out to get a nice balance on the helm. 

I was wondering whether a slightly bigger jib might be the answer, what do you think?

Cheers

[garethrow]

Ged   this is not a problem that I am familiar with - assuming your boat is genuinely flat. The S17 hull shape naturally turns the boat into wind when healing - not a bad thing. Also - I am not sure there would be space to enlarge the jib without a bowsprit.

Regards

Gareth Rowlands
Gwennol Teifi S17

[Ged]

Hi Gareth
It's interesting that you don't notice it on your boat, maybe it's something else that needs sorting. Do you sheet your mizzen right to the centre line when beating?

I'm pretty sure the boat is generally flat. It's only really been an issue since I fitted a leech tell tale on the jib, before that I just sheeted in the jib a bit and that got rid of the weather helm, but now I know that I'm stalling the jib by doing so.

I think it may be possible to squeeze a bit more jib in front of the mast by removing the cleats and a having longer boom that protruded a little more forward, I don't know if that would have a detrimental effect?

Cheers

[Graham W]

Ged,

It's been done before, on a SeaRaider and a couple of BR20's.  You might have to experiment with the position of the pivot point on the longer jib boom.  An extra benefit of the longer boom is that when locked amidships, you can fly an asymmetric spinnaker off the end!

[Ged]

That's interesting, I have been admiring Gareth's spinnaker and also your flying jib... more fun to be had.

How do you tension both the sails if they're om the same boom?

[Graham W]

If you want to fly a spinnaker from the same elongated boom as the self-tacking jib, you would have to furl the jib and lock the boom amidships.  One way of doing this is to hook a strop under the aft end of the boom and tie it to a cleat on the front of the mast.  I think Alf devised a way of tying it down to the foredeck instead.  You might also need to rig a bobstay from the front of the boom down to the towing eye on the stem, to stop the front end from waggling about too much.

Attached a photo of my (now abandoned) experiment with a longer jib boom, made from an old carbon spar.  In the end, I opted for a fixed but removeable plank bowsprit, off which I can fly any one of the following: large conventional jib, flying jib, code zero or asymmetric.  I usually combine the front sail with a self-tacking jib on its own jib boom, otherwise there is a bit too much string for a solo sailor to deal with all at once.  Apparently some old sailing barges combined a self-tacking jib with a flying jib on a fixed bowsprit, and they knew a thing or two about sailing short-handed.

[Peter Cockerton]

Hi
With the boat flat and the jib drawing nicely I get quite a lot of weather helm if I sheet the mizzen anywhere near the centre line. In fact I have to ease it quite a long way out to get a nice balance on the helm. 

I was wondering whether a slightly bigger jib might be the answer, what do you think?

Cheers

Matt commented once on Mast Rake impacting on sail balance, for the BR20 he suggested 3 degrees (leaning aft) if I remember correctly, other posts talk about reducing mast rake to ease weather helm.
Useful link below to measure mast rake with an iPhone/iPad.

https://www.youtube.com/watch?v=4mJh94Cm3zw

Peter C

[Ged]

Thanks Graham, that's an impressive collection of sails you have!

My mast steps into a socket on the floor, not easily adjustable but doable with some woodwork, I'll have to have a look at the angles.