 Author
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Topic: Jib leech twist – BayRaider (Read 1725 times)
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Alf Lande
Jr. Member
Posts: 4
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When going to windward I get the impression that the aft jib leech is too tight – hence the airflow over the lower part of the main sail is restricted causing turbulence over the mainsail.
I removed the sheeting from the jib club-boom, and attached the sheets directly to sail clew. This gave the jib more twist, and the drive from the jib improved significantly.
So my conclusion so far is that by sheeting the jib directly to the sail clew a more effective sailtrim is obtained when going to windward.
The down side is that the jib self-sheeting as well as the advantage of excellent jib control going downwind is jeopardised.
The cause of the stretched aft leech is that the tension from the forestay is counterbalanced by the jib aft leech tension.
Suggested improvement:
I am considering “fixing” the club-boom to the foredeck a bit forward of the mast foot. A peace of teak will be attached to the foredeck, and the clubroom to be tied down by ropes to this teak clamp.
When going to windward I will sheet the jib directly (fixing the club-boom sit in mid-ship position). When going downwind I intend to release the club-boom (un-tie the ropes), and pull tight the foot tension line which is attaching the boom and the jib clew. (The clubboom foot tension line should always be attached to the jib clew).
The loss of the self-tacking does not worry me much as the sheeting is so easily done on the BayRaider, and most often adjustments will have to be done after tacking anyway due to change in wind, boat heading etc.
I am interested in other sailer’s experiences wrt jib twist and possible solutions.
Any ideas, suggestions and comments are welcome.
Alf Lande
Stavanger
Norway
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Edwin Davies 2
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I have been thinking about this aspect of the self tacking jib setup. Not having a boat to experiment on. BR 17 on order. I noticed in a photograph of the BR in strong winds the jib seems to have too much twist. I hesitate to say it but on model racing yachts our self tacking boom is connected to the jib head fitting by a thin cord. This enables the luff tension to be set with no regard to leech tension as the twist in the sail is controlled by this leech line. I have no idea as to the practicality of this on a full size rig. I will be experimenting when I get a boat. It would be an ideal use for dyneema.
It may mean moving the attachment point of the jib boom to deck further aft to give more leverage.
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Craic
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When going to windward I get the impression that the aft jib leech is too tight – hence the airflow over the lower part of the main sail is restricted causing turbulence over the mainsail. ... Alf, cannot say I noticed myself. Interesting. If it is so as you say, and if one wanted to retain the self-tacking, one could change the balance of the clubboom. One could fit a strip of hardwood reaching out a bit further over the bow and bring the swivel point of the clubboom forward. Which would reduce the lever force on the aft leech from the luff tension. You could use the winch eye on the bow to absorb the tension on the overhanging wooden bit. Sort of a little bowsprit with a waterstay. OR, you could shorten the foot of the jib. Good luck with experimenting, sounds fun. |
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