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Let's make our H18's faster
http://www.hobie.com/forums/viewtopic.php?f=13&t=32847		 Page 2 of 4
Author:  ncmbm [ Wed Oct 27, 2010 5:34 am ]
Post subject:  Re: Let's make our H18's faster
And I will agree with SRM, too much nose weight is slower than a balanced boat. Keeping the boat still in light air is very helpful as it keeps the air attached to the sail. Moving about fluidly makes a huge difference in boat speed in light air.

I personally hate sailing in the light stuff, especially inland. I really prefer the small craft advisory type of wind. Cause "If it ain't blowing, I ain't going".

And learning to properly roll tack the boat from the wire is a talent worth training for, its not easy but the speed you can turn willl blow your mind.

Do you guys still "wild thing" downwind? With the spin that technique is suicide but I remember watching a Miracle 20 eat Tigers for lunch downwind using this technique.
Author:  OlderBowman [ Wed Oct 27, 2010 8:37 am ]
Post subject:  Re: Let's make our H18's faster
the key to downwind sailing is obviously to get to the mark in the most direct manner. if the wind shifts header, then down I go closer to the mark, if the wind goes high enough, it's time to gybe.

as for sail trim, put enough tell tales over your sails and you'll know when you've found optimum trim for your point of sail. just back from the leading edge, close to max draft and off the trailing edge, at 3 or 4 places vertically. I've sailed enough different kinds of boats, both mono and mutli, to know this is the common denominator to trim.
Author:  srm [ Wed Oct 27, 2010 9:26 am ]
Post subject:  Re: Let's make our H18's faster
Quote:
Do you guys still "wild thing" downwind?


I don't know that the true wild thing has ever been done too successfully on the 18, its really not fast enough and pretty underpowered compared to a boat like the 20. You end up sailing too high and chasing your apparant wind all over the place. When the wind hits around the 15 to 18mph range, I'd say we definitely sail the boat "hot". The mainsail will be sheeted in noticably tighter and the apparant wind at 90 degrees or even a little forward of that, but not really focused on keeping the windward hull out of the water and the traveler stays out near the hull, not brought in to the hiking strap like during the WT. Its kind of a 50/50 mix. I think there is definintely a windspeed where we transition from the low and slow technique to being sheeted in and sailng hot.

Quote:
the key to downwind sailing is obviously to get to the mark in the most direct manner.


I'd agree with that statement for the most part, however windspeed also plays a big role. If you can get hooked up in a puff that your competition doesn't get, you can make up huge ground. Boatspeed and direction are basically the deciding factors in the whole game.


sm
Author:  mboyer68 [ Wed Oct 27, 2010 1:47 pm ]
Post subject:  Re: Let's make our H18's faster
NCMBM -

I'm sure everyone would love to see your sweet self-tacking jib setup. Also your sails - what is different, is it draft position, size, squaretop, other ??
Any other secrets/tips/tricks you want to divulge ?

In relatively flat water, blowing just barely trap weather, how far should deck of leeward bow be above water if windward hull is just kissing the water ? From what i've read here, sailing sterns out and speed is controversial. Seems less accepted now than years ago for the H18. I don't have a position on it, i'm not that good - just asking.

Thanks,

Mike

ncmbm wrote:
I sail a '82 H18 and a '84 Magnum. The '82 is a custom monster with self-tacking jib, spin and SX mast. This boat is as close to an F18 as a H18 will ever get. I have full custom sails on it from Whirlwind, and I do mean custom. There is no one else sailing the same main shape as mine and I believe I have the only properly fit H18 self tacker out there, with the custom jib. I have played with many of the tricks on the H18 and most will never get the full power out of it. The Bergman book is only the tip of the iceberg of tuning options for the H18. I'm doing things with the mast Phil never considered.

Number one tip for H18 speed is to keep the sterns clean. What I mean is out of the water. On any point of sail the H18 is faster if the sterns do not drag.
Author:  ncmbm [ Wed Oct 27, 2010 5:45 pm ]
Post subject:  Re: Let's make our H18's faster
There are some pics on this site but the new jib is not. I will try and attach some this week. I have Whirlwind sails, the SX squaretop but I felt it was too flat above the hounds so Chip added a panel and put more curve in the luff. The sail is properly balanced now and the power in the top is very noticeable in puffs. I have raked the mast back and added precurve to the mid-section.
I have no love for the comptip, it is a constant issue to power transfer. I really should get a solid 29'6" stick for the boat.

I think you should go out in trap weather and walk around on the hull and see what the boat does. You can feel when its right, the sweet spot for that angle of sail. Each angle requires a different sweet spot for maximum speed.
Author:  Cork Guy [ Thu Oct 28, 2010 9:07 am ]
Post subject:  Re: Let's make our H18's faster
How about the Spreader Rake?

Should it be set straight across or raked back?

Any thoughts?

84 H18 with comp tip. I sail in mild to wild wind.

Corkguy
Author:  J_Eaton [ Fri Oct 29, 2010 5:38 am ]
Post subject:  Re: Let's make our H18's faster
Cork Guy wrote:
How about the Spreader Rake?

Should it be set straight across or raked back?

Any thoughts?

84 H18 with comp tip. I sail in mild to wild wind.

Corkguy

This following makes the most sense (to me anyway) of any discussion on "pre-bend". Throw out most general information you find on spreader rake when applying to the Hobie 18/18SX because the diamond wires attach to the side of the mast, not the front, which has effect on minor axis, as well as major axis, bend of the mast.
Dlennard wrote:
You have to fit the mast to the sail. Turn the boat over on its side and hook the main on top and then hook up downhaul and boom and main sheets. Just like you would use it to sail just do not put in the sail track. Use normal downhaul and sheet tension and mast rotation. Set your mast to fit the curve of the sail as best you can. This will be the setting that you want to use all the time.
Regarding mast rake (fore/aft) I always wanted the mast standing straight up, giving the most downwind speed possible. Reduces pointing ability sure, but I feel the boat needs less help going upwind. The boat sits down in the water, and doesn't seem to take off like a 16 or 20, going downwind.
Author:  ncmbm [ Fri Oct 29, 2010 7:51 am ]
Post subject:  Re: Let's make our H18's faster
Adjusting the mast to the sail is the proper approach, but it isn't as easy as it sounds. The H18/SX mast doesn't want to bend on the major axis. The diamonds will hold it bent but they aren't set well for tensioning. I found it easiest to bend the mast between trees and lock it then use the above method to compare, reset and compare again. It takes some time when you are doing something different than the original design easily allows. I still can't get the comptip to work like I want. Most of my downhaul goes into bending the tip instead of flattening the sail. I believe the sail is stronger than the tip!

Spreaders are back on my boat and if I could go a hole further out I would. I tend to sail heavy in big air. I often go with two crew on the wire and me driving in 25-30kts. I think Phil Berman(?) gives a 3 w's approach to spreader rake doesn't he?
Author:  Harry Murphey [ Fri Oct 29, 2010 8:20 am ]
Post subject:  Re: Let's make our H18's faster
Hi,

From H18 PerfomanceManual/Phil Berman Pgs 40-44

Light Wieght Crews: max spreader rake except in moderate winds/choppy water then meduim rack

Medium Wieght Crews: Same as Light wieght crews

Heavy Wieght Crews: Medium rake in light to moderate winds/flat water. Min Rake in moderate to heavy winds/choppy water
Author:  Cork Guy [ Tue Nov 02, 2010 8:43 pm ]
Post subject:  Re: Let's make our H18's faster
DOWNHAUL
A couple weeks ago I crewed on a H20 in Monterey Bay CA. The wind was strong 20+ and gusty. On the upwind legs I was working the downhall constantly per the skippers instruction.

Can the 18 be powered/depowered with the downhaul like a H20 in mid to heavy wind?

I have a 6 to 1 downhaul system but I'm thinging about upgrading.

Any thoughts?

Cork Guy 84 H18 with comp tip
Author:  srm [ Wed Nov 03, 2010 4:20 am ]
Post subject:  Re: Let's make our H18's faster
The effect of downhaul tuning is not as pronounced on the 18 as it is on the 20, but adjusting the downhaul "on the fly" is still beneficial. We don't play the downhaul as constantly on the 18 as we did on the 20, but for sure when we see big puffs or lulls coming down the race course, we'll crank in or ease off the downhaul as required. My boat is set up with a 6:1 system adjustable from the trapeze on both sides of the boat. For us, the system is powerful enough. If my crew has trouble pulling in the last inch of downhaul, she can hand it to me and I'll finish the job.

sm
Author:  ncmbm [ Wed Nov 03, 2010 7:07 am ]
Post subject:  Re: Let's make our H18's faster
I could never see any real difference in adjusting downhaul on the stock H18 sail. On the squaretop its a different story and it would be hard to sail without good downhaul, mine is 8:1 purchase and I would like 12:1 if I could find room for the hardware or a cascade system.
Author:  srm [ Wed Nov 03, 2010 9:16 am ]
Post subject:  Re: Let's make our H18's faster
ncmbm wrote:
I could never see any real difference in adjusting downhaul on the stock H18 sail.


It may be dependent on whether or not you have a comptip mast or not and whether or not your sail is blown out or old. My boat has a comptip and a relatively new sail (2 or 3 years old). I definitely notice a depowering effect and a lessening of weather helm when the downhaul is cranked in. Its not as dramatic as on a boat like the 20, but its there.

sm
Author:  Cork Guy [ Wed Nov 03, 2010 1:50 pm ]
Post subject:  Re: Let's make our H18's faster
Well it's the time of year to tinker. I think I will run the lines out to the traps and see what happens.
Is there a class rule on the downhaul ratio? If so where could I look it up?

Quote:
Maverick: I feel the need......the need for speed!!!

Team Sumo Round TI Regatta 2010 (500lbs holding it down)
Image

Absolute needs to sponcer another regatta these sails are getting old!!!!

Cork Guy H18, H18, H18
Author:  srm [ Wed Nov 03, 2010 2:55 pm ]
Post subject:  Re: Let's make our H18's faster
The max allowable downhaul ratio for the 18 is 8:1 per the one-design class rules.

You can download the rule book from: hca-na.org. Click on the "Class Info" tab, scroll down to "Class Rules" and then click on the link for the .pdf file.

sm
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