Hobie Cat Forums

It is currently Wed Nov 26, 2014 11:45 pm

All times are UTC - 8 hours [ DST ]




Post new topic Reply to topic  [ 6 posts ] 
Author Message
 Post subject: Light air traveler trim
PostPosted: Thu Aug 14, 2014 7:05 am 
Offline
Site Rank - Captain

Joined: Thu Nov 03, 2011 5:23 pm
Posts: 60
So last week I was racing at my club on a Wednesday night races, losing badly to mono-slugs on a tiny course; twice around windward leeward with elapsed time of around 8 minutes for me. My boat is a fully upgraded ’81, wet-sanded and polished hulls, 2013 EPO’s, low profile 6-1 mainsheet and jib sheet, aussie adjustable jib halyard, 6-1 downhaul. I was sailing in light air at around 5-8 knots, enough to be off and on the wire sailing solo at 160 pounds (72kgs for you metric people).

I was noticing that upwind off the wire in the lulls my main appeared over trimmed, specifically when I was pointing as opposed to footing. I had the main sheet blocked out and the luff tail tails were flowing on both sides (not stalling) and the leach did not look too tight, however the leach tail tails were “pocketing” behind the sail 95% of the time, telling me that the air was stalling at the end of the sail and that I was losing power. I read somewhere that you want the leach tells pocketing 50% of the time. Trying to fix this without letting off mainsheet and letting the top part of my sail stall, I dropped the traveler an inch to 2 inches (25-50mm), and that seem to fix the leach tell tails stalling and I seemed to gain a couple tenths of a knot, although that could have been a puff.
My question is that the normal procedure or should I have been easing off the main sheet a few inches and letting the top of my sail twist off?

If you can’t tell I’ve been racing lots of different boats for a long time, from 40’cruising mono hull’s on long distance races down to Formula 16’s at F-16 worlds, so feel free to blast me with technical details.


Top
 Profile  
 
PostPosted: Thu Aug 14, 2014 9:12 am 
Offline
Site Rank - Old Salt

Joined: Mon May 09, 2005 10:25 am
Posts: 2604
Location: Jersey Shore
The sail needs twist in light air. If you oversheet, you will completely stall the top third of your sail and kill performance. I recommend you put a set of telltails in the first or second panel from the top of the sail about 1/3 of the way back from the luff. If the leeward telltail in this upper set is not flowing aft, you're oversheeted. It's better to be undersheeted some of the time than to be oversheeted at anytime.

sm


Top
 Profile  
 
PostPosted: Thu Aug 14, 2014 9:24 am 
Offline
Site Rank - Captain

Joined: Thu Nov 03, 2011 5:23 pm
Posts: 60
I already have 3 sets of tell tails posistioned at the draft of the sail, all at different heights so i can tell what the air is doing (fully battented sails can be a pain to read), and all of the tell tails have windows to see both sides. One set is positioned at the top like you described. During this incident, they were flowing nicely before and after I eased the traveler, but if I eased the sheet they would start to stall, where as if I eased the traveler they would continue flying, but the leach tell tails would start flying instead of pocketing.


Top
 Profile  
 
PostPosted: Thu Aug 14, 2014 9:45 am 
Offline
Site Rank - Old Salt

Joined: Wed May 05, 2010 8:28 am
Posts: 746
Location: Clinton Lake, KS
8 minutes twice up and back?


Are you sure you just we not losing all your time in maneuvers, and that it actually was a boat speed problem?


Top
 Profile  
 
PostPosted: Thu Aug 14, 2014 11:07 am 
Offline
Site Rank - Captain

Joined: Thu Nov 03, 2011 5:23 pm
Posts: 60
I’m sure I am losing a lot of distance in tacks, however my tacks are not slow for hobie’s. I am going close hauled to fully sheeted on the new side in less than 14 seconds solo, 15 seconds if I’m going wire to wire. I know that the courses have a lot to do with it, however there is always room for improvement.


Top
 Profile  
 
PostPosted: Thu Aug 14, 2014 12:25 pm 
Offline
Site Rank - Old Salt

Joined: Wed May 05, 2010 8:28 am
Posts: 746
Location: Clinton Lake, KS
Rab1515 wrote:
I’m sure I am losing a lot of distance in tacks, however my tacks are not slow for hobie’s. I am going close hauled to fully sheeted on the new side in less than 14 seconds solo, 15 seconds if I’m going wire to wire. I know that the courses have a lot to do with it, however there is always room for improvement.



Just wanted to make sure we had that covered first. 8) twice around in 8 minutes is a lot of maneuvers..

Beyond that I am hoping you find some good advice I can steal. :D

Two weekends ago I was suffering the same fate. I was sailing heavy 400lbs (supposed to be teaching a new sailor) and racing skilled thistle sailors in 0-5mph conditions.. I had them on boat speed on the beat.. but couldn't point high enough to make it matter.. and even properly executed tacks cost WAY to much ground. With 5 mph or so breeze I could catch them on the way back down.. (except for Mr. former national champ thistle sailor God) Less than that I seemed to only maintain ground in the drift off... oddly it was right at the point in which they had enough pressure to fill their spins that I could catch them.

Then last weekend in Iowa at a HCANA regatta wind was 2-7mph, with only one little part of one race nearing the 10mph mark.. Water was lumpy/choppy due to powerboat wake.

The first couple races I was relaxed.. Ended up at the front of the fleet having left the beach with the boat setup well and a clear head.. I got beat on things other than boat speed... Then I thought I would try and find a wee bit of power by moving the Shrouds up a hole.. So I let off some rig tension then changed my mind and left the shrouds alone and instead just re-tensioned the jib halyard a bit tighter than I had it before.. The trouble is I didn't think about this change in the middle of the race.. I had to travel the jib out to keep from backwinding the main and then found the speed, but couldn't point. I had gone from at least matching boat speed with the leaders to them just walking away... The boat really liked the looser rig a lot better. It opened the slot and just seemed give a bigger 'window' of proper trim.. and allowed the main to provide a bigger variety of sail shape through the puffs and lulls...

I run the traveler a little close to center in the really light stuff and let out more main to drop the boom back off... then to get the leech shape right I have been pulling on a little bit of downhaul. It seems to help 'hook' the upper sections of the leech without having to crank on a bunch of mainsheet tension, which of course effects everything from the Main sail leach to the jib luff... Also I think moving the draft of the sail forward in lighter stuff while maybe not the fastest makes it easier to keep moving fast as the 'groove' feels a little wider when things are shifty as they are when it is light around here.

The biggest problem I have is fighting the urge to oversheet, and not shifting gears up/down at the right times.. Then I sit there frustrated while the fleet sails by... Then all the sudden.. "Oh yeah... duh!". Seriously.. I have a camera on my boat.. and I come back home, watch the video and see my mistakes clear as can be. Sure makes me feel silly sometimes, but way better than having no idea where the mistakes are being made... Oversheeting in light stuff, no matter how much I have tried to talk myself out of it still remains a problem for me..


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 6 posts ] 

All times are UTC - 8 hours [ DST ]


Who is online

Users browsing this forum: Bing [Bot] and 9 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group