J/30 Class Association Forums J/30 Forum Racing Tools and Techniques Perfect Trim

We just returned from a 200 mile PHRF destination race and were throughly clobbered by a Cal 3-30--albeit one with a former Laser national champion at the helm. Though we were second, it should not have been so bad. I realize that nothing subsitutes for experience, but what is the best way to consistently perfect trim? I think we are beyond the basic mistakes, but things like a combination of light wind and swell or heavy seas throw us off. (It did not help that an eagle crushed our Windex just before the race! It still worked, sort of.) Are electronic instrument packages likely to help? Are particular telltail arragements effective? Other ideas, techniques, references, etc.?

A common mistake in my experience is to try to point too high in light wind. Crack the sails off a little and sail a couple of degrees lower. Make sure you have some twist in the sails too. In light wind the difference in wind velocity is greater from sea level to mast height. The higher velocity at the top will look like a lift up there. Hence the twist in the sails.

Your sails should have the basic telltale setup. On the main, you should have telltales on the leach at each batten pocket. On the jib/genoa, three sets are needed about 12-18 inches aft of the luff and spaced evenly. Place the telltales at the points where you would fold the sail if you were to fold it in quarters from the head to the tack. Sailmakers typically put three on each side at the lower location for the helmsman to steer to. Set the fairlead so that the jib telltales all break at the same time. Other than that, in light air just try to keep the telltales all flying.

Somehow, J30s got the reputation of being weak in light air. I don't know where this comes from since we usually kick butt in light air. It is hard to get weather helm at times. Load the crew to leeward and forward to heel the boat and induced some weather helm. Loosen the rig some (before the race) if you know its going to be light. No backstay on at all. Get a solid vang to hold the boom up in light air so the main can take its designed shape.

I've never read or heard of any techniques for dealing with heavy swells in light air. Anybody else got experience in this area?

Alan,

Care to share your light air settings? Just how much do you "loosen the rig"?

Since I don't get much opportunity to race against other J30s, my settings are suspect. We typically race in lighter conditions so my rig is always set about 2 notches lower on the loos gauge. Around 42.

If I were going to get serious about changing rig settings, I'd look at what the J24 fleet does. The J24 tuning guides all have various settings for different wind ranges. Check out the links at
http://www.paw.com/sail/j24/

There are 4 different guides from 4 different sailmakers. I glanced at the NorthSails version. It has shroud tensions for 5 different wind ranges. Since the J30 is just a scaled up version of the J24, we should be able technically to scale the shroud settings up. I'd probably start by assuming the J30 standard setting is for the medium-heavy range and attempt to scale up the J24 numbers for a starting point. Then try it out.

The point is that the pros are changing their rig settings based on predicted conditions on the course for that day.

Eric:

Last year a friend and I did a 70 mile ocean race doublehanded. We were sailing in ocean swells off of Block Island and Martha's Vineyard. The one thing I remember about the settings on this race was that we had to crack the genoa off the spreaders about 8-12 inches. When we sail in Narragansett Bay, where there are no swells, we typically set the jib about six inches off the spreaders. Twisting the jib seemed to give us the power we needed. We sailed side by side with an Ohlson 33 for probably seven or eight hours. It was as if we were glued to each other. He was on our windward hip, in clear air. Try this setting in swells and see how it works.

Alan,

It works. In our first race on the boat we were expecting 5-10 and got it. I tuned her and sailed her like a scaled up J24.

Medium heavy settings for a J24 are about 800# on uppers and lowers, and for 5-10 it's 400# My J30 tuning guide calls for 2000# as an all around setting. I assumed the 2000# to be medium heavy and cut it in half for 5-10 to 1000#. With a somewhat limp headstay she powered up very nicely. We trimmed 6-12 in. off the spreaders depending on if we were toward the 10kt end or 5kt end respectively. I kept the top telltail on the main just a verge of stalling.

We won the race in an 11 boat fleet with a few very good light air specialists. Seems J30's go in light air just fine! Best part was rounding the last leward mark right behind a hot J29 from another fleet and beating him to the line up the final windward leg.

Try it! You'll like it!

Mark

Alright, Mark! Congratulations. Now we may see another race to create shroud settings for different wind ranges. I wonder if anyone will try this at the NAs?

Sounds like you've found a good setup. We typically set the uppers and lowers at the same tension, between 39 and 41 for moderate conditions of 8-14 knots. If it's looking to be a really light day, say 4-6 and sloppy I'd loosen 2 turns all around. At the top end of the #1 (15 knots true, 20 apparent) I'd tighten 2 turns and maybe another two at 20 true, 25 apparent. I try to tighten lowers first then uppers to get the bend up high. My sailmaker (UK) is always telling me all my fiddling is just getting the rig out of wack.

Seems North has been suggesting very loose lowers (relative to uppers) for light air. Anyone care to comment?