Spin run

On a blowing spin run, which sail has the most effect on the main, the spin or jib? Of course the power is in the spin, but does it overpower the effects of the jib on the main?

Thanks

I see that no one has chimed in your question, so I'll jump in here.

What is it that you would like to know? I think maybe the reason that no one answered is that the reasoning behind your question isn't clear. Are you wanting to depower a bit downwind?

The quick answer I guess would be that apairant wind has the greatest effect on the main.

I'll add my $0.02: Simple answer is the spinnaker has the most effect. By far.

I think there are a couple reasons:
1) Sail size: 21m^2 vs 4.2m^2.
2) Sail cut: the jib is cut very flat for tight upwind wind angles, while the spinnaker is deeper cut keeping attached flow at higher wind angles that are seen heading downwind.

So on the typical downwind run, I think the jib is mostly just enjoying the ride and has a very limited effect on the main's lee-side flow. That being said, every little bit helps, so the jib should be trimmed out with lots of camber. In my case, the top of the leach is almost completely open and not doing anything, but the mid and lower sections appear to draw a little bit - judge by telltales.

One last comment: An over-sheeted jib (one you forgot to release when you turned downwind) would likely be stalled and have a big negative effect, acting like a rock in the stream.

Any thought on the minimum distance between jib tack and spin tack to avoid interference with the slot between the two?

I know we left the jib up on F18 (what is the distance between the two?), and wonder if the same could work with a larger F24 (measuring the gap shortly).

I'm guessing in my case the spin tack is too close to the jib tack to leave the jib up. I think the distance between the two tacks/luffs is less than 72 inches.