Jib Track

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GRAEME JACKSON

Hi all    have a problem that when my jib is furled smaller than 100% to the mast the sheet cars do not go forward enough to set the sail properly, do i need to put another track along side to bring it closer to the bow. or should i just set sail to suit the car at its further most position and not try to furl any smaller
we sail in constant 15-20 knots of wind andthe jib seems to large.

Jon Schneider

I know what you mean, but I can't imagine that you'd really need to reef down to a blade at 15-20 kts.  What are you reefing down from?  A 130 or more?  That's a big leap, and unless you've got a high-performance sail that's meant to be reefed that much, the problem may not be so much in the jib lead position and the slot, as much as it's the condition of the sail itself.  Something's wrong there.  How old are these sails?  Sounds like they're blown out to me.  I also wonder if you've got too much sag in your headstay?  Just to experiment, you might try a "reverse" barber haul.  Attach a guy (probably a misuse of that term on my part) to clew of your genny (or perhaps to the sheet might be better) and to, perhaps, the mast to trim the genny windward.  Sorry for all the "perhaps," but you'll have to experiment.  I would try using a block at the mast base (perhaps the secondary jib halyard block temporarily?).  This will help you point up higher, but you'll also heel a lot more.  My suggestion is definitely not ideal, because I think it will also introduce a lot more twist up top, but it's worth a shot.  Also, remember that it's possible to close that slot up too much.  You want the slot open a bit in rough seas.  Personally, I would make sure your sail reefs well and that your main is properly trimmed to make the most effective slot and minimize heel in those conditions (and is de-powered) before I worried about the jib lead position.  Then again, I see a Doppler effect of a lot of transoms when I sail ;)
Jon Schneider
s/v Atlantic Rose #1058 (1990)
Greenport, NY USA

Ted Pounds

If the jib is too large  so that you're sailing with it reefed all the time you need a new  size jib.   Find a good sailmaker (ask around your marina) and get him/her to go out for a sail with you.  Then they can set you up with what you need. 
Ted Pounds
"Molly Rose"
1987 #447

Ron Hill

Graeme: I believe that your jib is not cut for roller reefing.  I have a 150 genoa that I can roll into 60% and still have good shape.  When I had that sail made that was one of the specs - reef able.

I agree that a talk with a sail maker will help you out.   :clap
Ron, Apache #788

Wayne

I sail on high wind SF Bay and have a 110 jib which is normal for my area.  My Catalina's tracks are a little too short.  My fairlead is usually almost at the forward end of my track, which would correspond more-or-less to yours in a reefed position (assuming you have the standard 135 jib).  When I reef my headsail, I can't move my lead forward to keep a tight leech.  Now for the good news.  With only a 110 jib, I always reef the main first which reduces heel and balances the rudder.  I try like the dickens to leave my full jib out, because I'm getting a lot of power=speed from it.  When I am still overpowered with a well-reefed main and need to furl in my jib, well I figure letting the leech open up on the jib and spill some air is a really good thing, because at that point the wind in REALLY blowing.
2006 MKII Hull # 1762
San Francisco, Ca

Jon Schneider

Here's another thought on how to test your theory without actually laying new track: put a snatch block on your aft chainplate and see if that position helps.  BTW, have any of your friends in Fleet 1 laid more track?  Stu, where are you?
Jon Schneider
s/v Atlantic Rose #1058 (1990)
Greenport, NY USA

rirvine

This is a little more complicated as the best position for the jib car depends to a large degree on the height of the clew above the deck and the shape / condition of the sail.   I know of no C34 on San Francisco Bay who has added jib track to allow the jib car to move forward. The racing fleet mostly uses 130% jibs (max allowable size) and usually survives by just reefing the main as the wind gets up.   

I agree with Ron - get some sail maker advice before taking any other action.

GRAEME JACKSON

sorry forgot to mention it is a 150%
too large are my thoughts
it is also made of 8 oz dacron which is too heavy for light airs
we are looking at getting it cut down to 110
the height off the deck is about 2 ft on a harken furler
the leading edge is too thick when furled to cater for 15kts plus
what weight dacron are the 110% ????

Jon Schneider

The problem with asking questions here is that you get all sorts of answers to questions you didn't ask, so, in that spirit, here goes: I would be wary of a loft that will cut down a 150 to a 110.  That seems like an enormous bit of surgery that will dramatically change the geometry of the cloth.  Have you received an estimate?  It may make a lot more sense to buy a used, legitimate 110ish and keep this 150 for light air days.  I know it's not an ideal cloth for light air, but I suspect it'll make a better light-air 150 than a radically-altered 110.  If you have a whisker pole, the cloth doesn't matter nearly as much, if at all.  Given that you're currently reefing a 150 down to a 90, I also suspect the poor performance has virtually nothing to do with the jib lead track.  You have a load of rolled-up cloth on the furler that's disrupting air flow.  No amount monkeying around with the clew position on this sail is going to significantly change that. 
Jon Schneider
s/v Atlantic Rose #1058 (1990)
Greenport, NY USA

Stu Jackson

#9
Graeme

It appears that it is not the track but rather the sail.

In windy SF we (personally) select our jib based on the season: summer, windy, smaller; winter, lighter air, larger jib.  In our case, we have an 85% and a 110%.  The racers use 130s.  I have only once in 9 years attempted to roll our jib up to suit conditions. First step is to select the right sized jib, then the next step is to reef the main first.  Of course, more "survival" conditions would recommend furling the jib, too, but that would let the air spill off the top of the leech which isn't a bad thing to do in heavy weather.

It seems from your descriptions that you are attempting to get service out of a jib over a much wider range of conditions that one would expect to be able to successful.

The choices you have were discussed by the respondents above: smaller jib for heavier conditions, assistance by sail maker, reef main first.  Most opinions over the years indicate a first reef in the main at around 18 kts.

Since we sail in usually windy conditions, I have been very comfortable with our very old and tired but still serviceable 110.  With a full main the boat moves well in lighter airs and as the wind builds we have a complete range of options available to us without ever being over-canvassed.  We raced during the summer with our "big" jib, the 110, but generally switch to the 85 when summer arrives for cruising.

Since the boat is driven by the jib of the masthead rig, having an over-sized jib for windy conditions is not helping with boat speed.  I can't comment on the sailcloth weight, but it does appear that the comment that the heavy weight is counter-intuitive to light air for a large jib has great merit.
Stu Jackson, C34 IA Secretary, #224 1986, "Aquavite"  Cowichan Bay, BC  Maple Bay Marina  SR/FK, M25, Rocna 10 (22#) (NZ model)

"There is no problem so great that it can't be solved."

George Bean

#10
A couple of other things that affect "reefed" headsail performance are; that big wad of furled sail disrupting air flow over the remaining sail, the diminished tension on the luff (as the halyard is not tensioning the new "head"), and the center of effort migrating (along with the clew) up and outwards.  We all reef the headsail from time to time, but we must settle for the degraded performance.

I'm no fan of the "one size fits all conditions" philosophy.  I think that it sort of works, but if you are performance oriented, I suggest you get purposed made sails.  And like Stu, match the sail to the predominate conditions (but sometimes we get it wrong as the second photo of our blade in action suggests).  Our "blade" is a hollow roach 95%LP with a high clew – "Yankee Foot" and is made out of high modulus 8.62 oz Dacron.  The sail will beat to windward like nobody's business, but has nothing for downwind.  Our local Quantum loft did a great job measuring and fitting the sail to Freya, and even with the high clew, the fairlead is still mid track.  Your 8 oz is better suited for a lapper or blade than a drifter.  Get some quotes from your sail maker and get it cut down, you'll be happy with the results.  For comparison, the first photo is Stu single handing Aquavite  with his 85% in 25+ kts of breeze.  The third photo shows Aquivite's "racing" 110 and Freya's 130 for comparison.
George Bean
s/v Freya  1476

Stu Jackson

1.  Just for the record, the last photo was most likely during pre race maneuvers, since I do not ever remember being ahead of George during any race   :D

2.  Graeme, here's a post from a search on "jib" that's pertinent:  http://c34.org/bbs/index.php?topic=2055.0  There may be more.
Stu Jackson, C34 IA Secretary, #224 1986, "Aquavite"  Cowichan Bay, BC  Maple Bay Marina  SR/FK, M25, Rocna 10 (22#) (NZ model)

"There is no problem so great that it can't be solved."

Ron Hill

FYI : After many posts over many years --Most people that have a tall rig opt for a 135% MAX head sail rather than a 150% Genoa.    :wink:
Ron, Apache #788

Mike Vaccaro

It's practical to cut a 150 to a 100% working jib if you raise the clew (yankee foot)--turning your big genny into a lapper.  This has the added advantage of increasing visability for cruising and doesn't require any additional track or blocks forward for trim.  This is a good sail for beating into heavy weather.  Very limited utility for down wind work as pointed out--almost useless unless you have a whisker pole rigged.  This is our primary headsail for family cruising, but we supplement with a small symmetric chute (41' Luff) for down wind work.  For cruising, we'll generally set the small chute like an asymmetric using an ATN tacker to secure the tack to the head stay.   

Cheers,

Mike
1988 C34 Hull #563
Std Rig / Wing Keel