I have set up my rig to the Doyle racing settings and my boat is now not pleasant or easy to sail due to needing huge muscles. At this point, I need to say that my sails are past their best. With no new sails in sight does anyone know how to set the rig making the boat easier and gently to sail while hopefully not losing too much point ability? Looking forward to your comments.
I`m not sure if I can help or not but I`ll give it a try.I `ve had my j30 for 5 yrs.now & the second year i had it I had a similar problem. I noticed an excessive rake aft in the mast. This created lots of weatherhelm.So I readjusted the fore stay and shrouds so there is just about 6 or 8 in. of rake.The fore stay appears maxed, the mast is back against the opening in deck. the upper shrouds are approx 40 on guage & lowers are approx . the same.The shrouds are never loose on leward side.My helm is very comfortable to weather now, but off the wind it can still be excessive. this is the nature of the beast.Sail trim is very important in reducing helm as well. It is not hard to loose control in close quarters in gusty conditions.How long have you been sailing the j30? I also balance my rudder, but I don`t think this is legal if racing one design. It did help reduce helm off the wind but did not eliminate it. Good luck, Clive J
dwl
Senior Member
Registered: 03/26/00
Posts: 124
Loc: New York, NY, USA
When you say needing huge muscles, I assume you're talking about getting tons of weather helm? Yes? In what conditions? The Doyle settings don't tend to produce boat loads of helm, although they do work hard to power up the lower two thirds of the main. If your main is really something of a bag, that may not be ideal.
A couple of things to look at. How's the helm in five knots, ten knots, and fifteen knots? Do you work the jib cars back when the breeze comes up if you keep the number one going? If you cary the one up above fifteen knots, it starts to pay to let the top twist open a little and dump some pressure.
I assume that you're careful not to carry the boom above centerline. In almost all conditions, that's slow. and a great way to induce big biceps in the driver as the wind builds. Also, be careful, as the breeze builds, to start thinking about when to put backstay on. You don't need a lot, but at some point, you need some. This has two desirable effects. It flattens out the main, which depowers it a bit, and lowers helm pressure. It also tightens up the headstay a bit, which flattens the jib entry, allows you to point a touch higher, and should make it easier to feather up if you're getting overpowered. A couple of things to really watch for, when you get enough breeze to be working hard. The boat *hates* to be stalled. It needs to keep moving, even if you have to scallop up, pinch for a moment, then put the nose down and accelerate. The keel's a bit on the small side, not terribly inclined towards generating lift, and needs good flow over it to keep the boat from going sideways. In general, this also means, don't let the boat get blown on it's ear, even if it means dumping traveller. Also, don't forget to keep an eye on outhaul, and cunngingham as it starts to blow.
As far as losing point, well, if you start shortening the headstay, you'll lose some point. I also expect you'll also start to generate lee helm in light air, and neutural helm in light to moderate air. I find those much harder to cope with than too much power, but your milage may vary. Whenever the headstay's too short, I find I tend to fall out of the groove to leeward, a sign of not getting enough weather helm. I'd rather keep the headstay long, put on backstay when I need it, flatten the main when I need it, and keep the boat lively in lighter air.
C. Johnston I'm interested in how you balanced the rudder. I put a couple of thousand miles on my J/30 cruising in Mexico and one of the few things I wished for was a balanced rudder so that the autopilot would have an easier time. Did you add area to the leading edge by eyeball? Involve a designer or naval architect? Change the turning axis on the existing rudder? Some trick I haven't thought of yet that doesn't involve modifying the rudder?
Mark
Senior Member
Registered: 06/04/00
Posts: 166
Loc: Belleville, IL, USA
I have found that I have little weather helm as long as the genoa is trimmed in hard. In heavier air I can tell when my crew is tired and leaves it out too much by the amount of helm. I have a lot of rake and prebend in my mast to induce as much helm as possible. In fact I'm almost sure my headstay is set too long (2" - 3") for class, but I race PHRF exclusively. I have my uppers and lowers at 43-44 on the guage.
dwl
Senior Member
Registered: 03/26/00
Posts: 124
Loc: New York, NY, USA
Jib car position affects the weather helm load you get in breeze. You can lower the weather helm a fair bit by going back further on the jib cars and allowing the top of the jib to open up a bit and spill some of the heeling force. You're also flattening the sail and making the shape less powerful, and less inclinded to round you up. related to sweating in the jib hard, but with slightly different behavior.
Jim, To balance the rudder I cut about 1.75 inches out of the front of rudder just around waterline making sure leading edge would slip under hull,I`d have to take a look to remember exactly.This moved Gougens or pintles(which ever)back. I also added about 2 inches to the back slanted top part of rudder to give it the same appearance as before. I didn`t touch leading edge of rudder thereby not altering the foil shape.I think I could have increased the measurement by half inch or so ,this would have put the leading edge just forward of the pins.(terminology is bad)My helm is still heavy off the wind by times and my Autohelm 800 has a hard time keeping course. I think there is a bit of guess work involved . Maybe if you could find a spars rudder to try it and do a bit of experimenting .I`m bad for frigging with my boat, I also put a retractable bow sprit in, All I need are a couple af assy. sails,but my wife thinks the hole in the water has enough money poured in it now.
Mark, I could be wrong on this and maybe someone can correct me if so. Your uppers and lowers seem tight. I feel lowers should be a bit looser then uppers so you can induce more bend in mast and flatten main as the wind picks up. If you have too much prebend, then you cant power up in light air as well.Also with lots of rake you may find it hard to power down as the wind picks up. There are no other J30`s in this area so I can`t really compare with other boats.
Mark
Senior Member
Registered: 06/04/00
Posts: 166
Loc: Belleville, IL, USA
We sail on some of the flattest water I imagine any J30 sails on (A large flood control resevoir in southern Illinois, Lake Carlyle. Why we sail such big boats on such small water I just don't know. Perhaps it's an incureable illness!) and have done very well with these settings so far. Set up this way (44 uppers and lowers with an extra long headstay) last weekend we had two races in 10 - 15 and 12 - 20 and we were untouchable in our fleet of boats. I was amazed at how well she pointed and I didn't have any problem depowering or powering up in these conditions. (It might be important that I'm sailing with a 155.)
This Saturday might be a different story. We're expecting <10. I have been tuning the rig way down (38 - 40) for light air, and have been beat by some good light air boats, but this time I'm going to leave it tight. I've also tried looser settings (40 - 42) with less prebend and rake in winds similar to last weekend and tight with rake and bend is clearly better.
I imagine the flat water is very important for the success of this. I have to work speed up out of a tack and work into pointing mode. It takes a minute when the wind is more toward 10 than 20. In waves of substance I expect I'd never get going.
Anyway, the point of this was a response to Mark Leach's question. Even with a lot of rake I find the weather helm manageable even at the upper end of the #1 as long as the #1 is strapped in hard. We do twist off the top in the heavier air, as dwl suggests.
YMMV
Follow-up: The wind didn't blow at all Saturday, so we didn't get to try it. Got a lot of swimming in though.
[This message has been edited by Mark (edited 07-22-2001).]
Mark Leach:I assume you have an old Doyle tuning guide from the early-mid eighties. When I shared my Doyle guide with my sailmaker (Doyle), he didn't even know the author. I tried the Doyle guide for about 1.5 seasons with pretty good results in light air against 30' masteheads. I then tried the Banks guide on the J30 website with better results in mid-heavy air. Since then, I have developed my own settings for my local area and PHRF fleet. IMHO, a tuning guide is directly related to your sails - if you have an old blown-out main, then you will likely need more prebend to flatten the sail. On Lake Ontario, we either have light air or heavy air and little medium winds so my sailmaker cut my main (for example) quite flat and my rig settings reflect this - I carry a very straight mast with minimal prebend to make the main as full as I can. The prebend suggested in the old Doyle tuning guide would result in large overbend wrinkles in my new main. I also find the Banks tuning guide is not competely applicable to the PHRF sailor and I tend to carry a very tight rig with 40+ on the Loos guage (like Mark from lake Carlyle). The tight rig is necessary to generate enough forestay tension for pointing when the wind isn't strong enough for backstay tension - convincing the J30 to be competitive against masthead rigs requires some experimentation. At the end of the day - any tuning guide is a suggestion and you must consider the cut and condition of your sails.
One last note on weather helm - we smoke (I mean s-m-o-k-e) when its windy so I'm confident in our approach to heavy air. The helmsperson (my wife) strikes a balance between feathering the boat into the wind and scalloping a little for power. We play the backstay quite a bit and make small adjustments in the main and genoa (we're talking +/- 1" adjustments) as we power up and down. The genoa is constantly trimmed to be 1" off the speader. We will roll boats that owe us over 15 sec/mile to windward in big chop and gusty conditions. We do, however, have weather helm and the Tarten Ten fleet noticed (as we pointed higher and sailed faster) that my wife steers with two hands and has to muscle her way through the waves. A flattened main, a properly trimmed genoa, and feathering will greatly reduce waether helm but its the nature of the boat.