Hi expert speedsters

How much difference does batten tuning make?

I recently bought a 5.0 and 6.2m Patrik SF set of cross-over sails for Slalom (Fin) and Foiling.

On Slalom they feel perfect. Great feeling, cam rotation is epic... the cams are so tight on the mast but flick around easily with wind from behind!

On Foil they feel again very good, but if I'm hyper critical, a little bit soft... I can feel the luff curve change in gusts.

So I want to know what happens to a sail if you replace the battens with stiffer ones... does it harm the slalom performance, making the sail too stiff and not forgiving over chop or gusts?

Thanks

I'd personally leave it be

That beautiful 6.3 is for sale now!

Select to expand quote

berowne said..

How much difference does batten tuning make?

won't go into rather complicated details since you're selling that sail.

but the short answer is: a lot, at least on the fin side of things.
suffice it to say that in the PWA, they need to use production boards and production sails; but they can use unlimited fins and sail battens. and believe, they do (or used to when it was all/mainly fins)

That sail looks very nice!

from my experience:

Changing the shape/taper of the front of the batten in cam sails makes very little difference and can actually destroy cam rotation, or lead to other issues with it. On most sails the profile shape is pretty much locked in by the sail shaping and changing the batten tips has little or no effect on it.

Changing the rear part of the battens can make a HUGE difference. Softening can allow the draught to move back, stiffening can really stabilise the draught. I am almost always looking to use the stiffest battens possible on the rear end of the battens. But some gains can be made in certain conditions by using softer battens around the boom to allow the draught to be a bit further back.

@ 5.15 covers the subject

Select to expand quote

sailquik said..
That sail looks very nice!

from my experience:

Changing the shape/taper of the front of the batten in cam sails makes very little difference and can actually destroy cam rotation, or lead to other issues with it. On most sails the profile shape is pretty much locked in by the sail shaping and changing the batten tips has little or no effect on it.

Changing the rear part of the battens can make a HUGE difference. Softening can allow the draught to move back, stiffening can really stabilise the draught. I am almost always looking to use the stiffest battens possible on the rear end of the battens.

great summary! thanks! that mostly correlates with my experience/findings. i agree that stiffer taper sections aren't likely to improve the OP's sail from fin to foil mode and may bring in some unwanted rotation issues.

Select to expand quote

sailquik said..
But some gains can be made in certain conditions by using softer battens around the boom to allow the draught to be a bit further back.

this in an interesting insight!
i did not get conclusive results from cross-batten tweaking and may have to experiment some again.

Select to expand quote

choco said..
@ 5.15 covers the subject

great find!
thanks

Do you rig the exactly the same for fin & foil? I use the Patrik GT3 5.0-7.4 for both and love this rig on both fin & foil. I aim to rig them the same way regardless of fin or foil. To spec & only maybe -1cm on DH. Lots of adj for draft with OH.

Contact Patrik. He will help you out

i would leave the battens alone. a lot of testing was done on batten stiffness!!! Hours and hours. you do need to adjust the tension on the battens they dont look good. Which mast are running?