SO30i - trimming the aft/backstays

[Torsten]

Hi folks,
I have a SO30i year 2013 which is very similar to the SO33i.
This boat has the standard rigg, so not the performance rigg.
The standard rigg has a completely splitted aftstay (i assume backstays is not the correct wording). To get the forestay more strenghted it may need a modification to the aftstays which are now just fixed without any chance to shorten.
Does anybody has experience on the needed modifications ?
Do I really need the total splitting or can I have one Aftstay just splitted 3m above the deck ?
Cheers
hansi

[rene460]

Hi Hansi,

I have a 2009 SO30i which also has the standard rig with twin back stays.  However the back stays have turnbuckles at deck level which allow adjustment.  If you have no turnbuckles I would suspect that you might have a turnbuckle in the forestay as part of the furler mechanism, as some adjustment is necessary to enable rigging the mast.

I found that back stay adjustment alone was not sufficient to tighten the forestay and some adjustment of the upper side stays was also required, along with some minor adjustments to the lowers to ensure the mast stayed straight.  The Selden rigging guide is a great reference for how to do it all.  It is available on line, and seemed to be all that was available to the local agent, but your agent or his rigger may have more information.  I had a couple of recognised experts check it all after I finished.

I have no idea on the advisability of changing to a single back stay, split near the lower end, which presumably you would make adjustable.  Perhaps worth contacting your Selden agent (assuming you also have a Selden mast).  This scheme is more common on a flexible mast rig where the back stay tension is an important on the water adjustment.  Turnbuckles are probably more appropriate with our stiff masts which should not require frequent adjustment.

rene460

[j]

Have you seen this: www.jeanneau-owners.com/hintsandtips/SO32adjustablebackstay.html

[bikerwookie]

I have done it to my so 33i pretty much the same as the 36i in the hints and tips. It will point higher once the forestay sag is taken out. More backstay also depowers the main but not as much as a fractional rig. You can test it out by putting a rope between your existing so back stays around 3m up and tension it that way.

[Torsten]

Oct 13, 2013 10:02:33 GMT j said:

Have you seen this: www.jeanneau-owners.com/hintsandtips/SO32adjustablebackstay.html

Yes I've seen it before and already did something similar on my previous boat.
Thanks !

Hi Hansi,

I have a 2009 SO30i which also has the standard rig with twin back stays. However the back stays have turnbuckles at deck level which allow adjustment. If you have no turnbuckles I would suspect that you might have a turnbuckle in the forestay as part of the furler mechanism, as some adjustment is necessary to enable rigging the mast.

I found that back stay adjustment alone was not sufficient to tighten the forestay and some adjustment of the upper side stays was also required, along with some minor adjustments to the lowers to ensure the mast stayed straight. The Selden rigging guide is a great reference for how to do it all. It is available on line, and seemed to be all that was available to the local agent, but your agent or his rigger may have more information. I had a couple of recognised experts check it all after I finished.

I have no idea on the advisability of changing to a single back stay, split near the lower end, which presumably you would make adjustable. Perhaps worth contacting your Selden agent (assuming you also have a Selden mast). This scheme is more common on a flexible mast rig where the back stay tension is an important on the water adjustment. Turnbuckles are probably more appropriate with our stiff masts which should not require frequent adjustment.

rene460

Thanks !
Good to read that I am not the only one in this world with a SO30i
It seems that we have the same Selden mast and yes there are turnbuckles at the back stays near deck Level.
I will try to double check with Selden about the proposed modification.
Are there any other mods you did to your SO30i ?

Oct 14, 2013 12:00:48 GMT 2 bikerwookie said:

I have done it to my so 33i pretty much the same as the 36i in the hints and tips. It will point higher once the forestay sag is taken out. More backstay also depowers the main but not as much as a fractional rig. You can test it out by putting a rope between your existing so back stays around 3m up and tension it that way.

Thanks for you comment I really appreciate it !
And it sounds that you know what you are talking about but I am aware that the splitted back stays are needed to support the mast properly. So maybe a single back stay could be dangerous for the mast?

[rene460]

Hi Hansi,

I adjusted the back stays using the ruler method in the Selden guide.  I measured the gap between the ends of the two screwed end connections in the turnbuckle with callipers so I could reset as necessary.  I found I could only go so far before further adjustment did not result in more tension.  Perhaps the hull was flexing, so I backed off a bit and went to the upper side stays.  I took pictures of the sails from deck level and two different sailmakers advised that forestay sag was ok but sail camber was too deep, with max depth too far aft.  To cut a long story short, I bought new sails with good cloth and tri radial cut.  It is like a new boat and now a delight to sail.  Poor sail shape causes many handling problems which you will recognise and can read up on in many books so you understand what the sailmaker is saying.

Other changes?  Solar panel on top of Bimini, extra battery capacity, a sock for the asymmetric, Wilchard boom brake, feathering prop, and lots of sailing, all well worth the effort.  It is a great boat.

rene460

[Torsten]

Hi  rene460,
thanks again for your help.
Here in Germany it is now autumn and the boats will get out of the water for approx. 5 months.
I will use the winter time for preparing the back stays improvement.
Do you share picturees of your boat somewhere ?
Kind regards
Hansi

[Torsten]

Here's my plan for the new backstay



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