Darren Gilbert asked me about my head stay length because I sail with an older pre-Rondar hull.
I'm not sure what my headstay length is now. I know that it is a good bit longer than when I first published my measurements for tuning the carbon mast way back in 2008, and I know it is longer than the Rondar or North tuning guides.
This is primarily because I have moved the mast butt back.
I adjust the headstay only once at the beginning of the season to suit whichever set of sails I'm going to use and then I leave it the same in different wind strengths.
I think of headstay length and mast butt position as something to tune in tandem. The objective of headstay/mast butt tune is quite simple. It affects rake and upwind helm balance.
Lengthening headstay+ moving mast butt back reduces lee helm/increases weather helm.
Lengthening the headstay without moving mast butt back, reduces lee helm/increases weather helm and increases rake.
The first priority is to balance the helm. So I take my new (or used) set of sails and go sailing upwind with the rig tuned in all other aspects (consult your friendly sailmakers tuning guide) in medium conditions. I make sure that I have the mainsheet sheeted really hard and the boat flat to 10 degrees of weather heel. I want a neutral helm. Beyond 10 degrees I want a "bite" of weather helm. If I don't have enough weather helm, or if when flat I have sever lee helm. Then I crawl forward and lengthen the headstay. If I have weather helm when dead flat or too much weather helm when heeled, I crawl forward and shorten the headstay. When it feels right. We sail in, haul the boat and look at rake.
Ideally, it would be much nicer to have someone motoring alongside in a RIB and taking pics (hint hint Barry) of rake but I don't have access to that early in the season. So I do it by eye on dry land.
So far rake has not been a super sensitive tune for me. I have experimented by balancing the helm (Thru adjusting headstay length) with my mast butt in two different positions one hole apart. I didn't notice much difference except that it "played with my head" for a couple of weeks because every marking had to change, mainsheet mark, gnav mark, jib tack length etc.
In 2011 I moved my mast back from the previous two seasons and felt it was better (thus making the mast more vertical). In 2012 I moved it forward (more rake) and felt that was better. As long as I keep feeling better, I guess I should just keep moving it back and forth. No seriously, I seem to have reached a compromise that works.
I feel that as one moves the mast butt back, the mast is closer to standing over the chain plates which means more prebend around the spreaders. But also less protection for the rig downwind. As one moves the butt fwd, the increased rake seems more like a 5-0-5 set up for big breeze. BUT really I cant discern much between the two settings I have tried. One is Pepsi and one is Coke. Brad, Ched or Keith might have a more discerning input.
So on land. If the rake looks more than I am used to then I will move the mast butt back. If the rake looks less than I am used to, I move the mast butt fwd. Then I have to go sailing again and retune the headstay as above. So usually, my crew and I look up at the rake, rub our chins and say "Look good to you?" "Looks good to me"... and go into the pub for some room temperature beer.
In conclusion. My recommendation for headstay length is to start with the tuning guide length. Then go out and lengthen it/shorten it to get your helm to feel right for you. Every boat, crew and sails combination is slightly different and headstay is the great equalizer for helm balance. Its the easiest adjustment to tune on the boat.
BUT REMEMBER. Don't do this on race day. This is something that you do on the practice day before the regatta.
1) It will mess your head if you do it on race day
2) Its against the rules to adjust the headstay on race day.
Hope this was helpful. I will discuss insurance in my next post.
Headstay needs to be slightly longer in the Pre-Rondar boats than Rondar boats.
Remember when tuning headstay, you need to adjust the shrouds and chocks after altering headstay length.
I don't understand this Justin. I would think the opposite.
The headstay attachment point is about 3/4" farther BACK on a Bennett which means given the same mast butt position you will need a shorter forestay on a Bennett to get the same rake.
I've found this to be an advantage over the Rondars. I always like my forestay to be as short as possible - to help reduce sag. This becomes more important as the breeze builds, so it's good that you are able to reduce rake (shorten the forestay) as the breeze comes up - since weather helm increases.
There is also a class rule that limits headstay length (not rake)... so on a Bennett you can actually get more rake than you could a rondar.
I would recommend starting out with max rake - going sailing, and tightening up the headstay length in various conditions until you start loosing that weather feel. Make notes and that is where you want your headstay length. (rules also state you can only do it once / day before you leave dock I think, so consider that when choosing for the conditions)
Other things that will affect weather helm and thus how long you want your forestay are
a) rudder angle - old Bennett rudders are more forward swept and it's more difficult to get weather helm. But Justin likes it because it gives him more control down-wind (he is crash prone)
b) mainsail depth
I've never messed with the base of my mast - but probably should. I think I measured Brads boat and did the same. When in doubt, that's probably a good thing to do.
Quote from: Justin Scott on June 05, 2013, 12:09:40 PM
Headstay needs to be slightly longer in the Pre-Rondar boats than Rondar boats.
Remember when tuning headstay, you need to adjust the shrouds and chocks after altering headstay length.
Jeff, I'm interested to hear what point of reference you measured from when comparing your bast step position vs. Brads?
Do you remember what these measurements were?
Since you've owned a few different Vipers, did you notice much of a difference in this measurement between the boats?
I think I measured from the front of the keel (as it would sit in the down position) to the back of the mast and copied it. In terms of weather helm, those are the two most important variables - moving either makes a dramatic difference in helm. So I wanted to make sure I had the difference between the two - the same.
I was also relatively confident that all the keels are in the same place in these boats (from various generations). It's the only thing I have confidence in being the same. So that was my starting point. Sorry, I don't remember what the measurement was Darren, I just make sure it was the same. My mast base was set and forget.
I really didn't pay any attention to it when I owned 102 or 129. Sailed as it was set from the factory.
I was always less concerned about mast base position - far more about that forestay length. now, had I ever got to the max length point and not had weather helm, I would have then started messing with the base.
If you have an old rudder i'd recommend looking at getting a new one from Whitecap. The new rudders not only allow you to shorten your forestay while maintaining the same feel - but they are quite a bit lighter than the old ones.
Get'em black sheep
Quote from: Darren Gilbert on June 05, 2013, 02:32:26 PM
Jeff, I'm interested to hear what point of reference you measured from when comparing your bast step position vs. Brads?
Do you remember what these measurements were?
Since you've owned a few different Vipers, did you notice much of a difference in this measurement between the boats?
Quote from: Jeff Jones on June 05, 2013, 02:10:58 PM
The headstay attachment point is about 3/4" farther BACK on a Bennett
Well there's no accounting for where you attach your fittings when you rebuild your boats. But on everyone else's boats the headstay attachment on the Bennett is marginally forward of the point on the Rondar.
There are Rondars, Bennetts and Jonesys.
Quote from: Jeff Jones on June 05, 2013, 02:10:58 PM
I always like my forestay to be as short as possible - to help reduce sag. This becomes more important as the breeze builds, so it's good that you are able to reduce rake (shorten the forestay) as the breeze comes up - since weather helm increases.
The difference of an inch or so will not have much impact on sag. An inch of wire wont add a lot of stretch. Head stay sag is controlled with rig tension and chocks. Sure, if you shorten your headstay and don't adjust your shrouds, the rig tension will increase. But you should be adjusting head stay length to tune the balance on your helm, not to control head stay sag.
I like to set up my helm so I feel the right amount of weather helm when I'm heeled about 15 degrees. If I am heeling more than that in big breeze, I prefer to flatten the boat rather than shorten the head stay to counteract weather helm .
In big breeze, conventional wisdom is to put more rake on. This is because (a) You are easing the main in puffs to keep the boat flat and this creates lee helm (as long as boat is kept flat) and (b) I think it is something to do with opening the slot and keeping CofE low.
Jeff has always been opposed to (a) Convention and (b) Wisdom......so naturally Jeff advocates shortening the head stay in breeze.
Now here is a funny thing. I feel the same way. In honking breeze I have this primeval desire for an adjustable headstay on the Viper, so that I can whale on it in monster puffs. But I think its because my gut wants to tighten the rig in puffs and depower the jib rather than because I have got some virus from Jeff. But, I have been spending too much time with him in the past 3 years, so who knows?
I never touched my forestay fitting.
Can someone else take a measurement for me. I'm 99.9% sure the Bennett points are exactly 3/4" farter back than any Rondar I've ever owned.
I'll do some measure and report back. If someone else could that would be cool.
Quote from: Justin Scott on June 06, 2013, 12:26:29 PM
Quote from: Jeff Jones on June 05, 2013, 02:10:58 PM
The headstay attachment point is about 3/4" farther BACK on a Bennett
Well there's no accounting for where you attach your fittings when you rebuild your boats. But on everyone else's boats the headstay attachment on the Bennett is marginally forward of the point on the Rondar.
There are Rondars, Bennetts and Jonesys.
Jeff - I will be at Chicago Noods this weekend and can measure 29,41,43,55,57 (Rondar Boats), 106 (Rondar UK) and 195 (Rondar USA...I believe). What is the reference point when doing this measurement?
First, you don't typically ease the main out on a viper during big puffs. Maybe a few inches, but not a lot. When you ease the main your forestay sags - and actually powers up the jib. When you're sailing in a breeze you keep your main on somewhat hard, and play the jib. Thus, there is no reason to increase rake in a breeze. Ease jib - pinch.
Actually, Brad Boston is the guy who recommended shortening my headstay as the breeze comes on. But hey, what does that guy know.
My philosophy has always been to a) follow the smartest guy on the course (not necessarily the fastest) b) take rig tune advice from people who are faster than me c) avoid overturned boats on windy down-hill runs - always listen for Ched's voice telling Justin to get out on the keel).
Quote from: Justin Scott on June 06, 2013, 12:41:33 PM
Quote from: Jeff Jones on June 05, 2013, 02:10:58 PM
I always like my forestay to be as short as possible - to help reduce sag. This becomes more important as the breeze builds, so it's good that you are able to reduce rake (shorten the forestay) as the breeze comes up - since weather helm increases.
The difference of an inch or so will not have much impact on sag. An inch of wire wont add a lot of stretch. Head stay sag is controlled with rig tension and chocks. Sure, if you shorten your headstay and don't adjust your shrouds, the rig tension will increase. But you should be adjusting head stay length to tune the balance on your helm, not to control head stay sag.
I like to set up my helm so I feel the right amount of weather helm when I'm heeled about 15 degrees. If I am heeling more than that in big breeze, I prefer to flatten the boat rather than shorten the head stay to counteract weather helm .
In big breeze, conventional wisdom is to put more rake on. This is because (a) You are easing the main in puffs to keep the boat flat and this creates lee helm (as long as boat is kept flat) and (b) I think it is something to do with opening the slot and keeping CofE low.
Jeff has always been opposed to (a) Convention and (b) Wisdom......so naturally Jeff advocates shortening the head stay in breeze.
Now here is a funny thing. I feel the same way. In honking breeze I have this primeval desire for an adjustable headstay on the Viper, so that I can whale on it in monster puffs. But I think its because my gut wants to tighten the rig in puffs and depower the jib rather than because I have got some virus from Jeff. But, I have been spending too much time with him in the past 3 years, so who knows?
I don't know Darren, maybe where the bow terminates? Like that outer lip? That's a solid point in the tooling and I don't think it's changed since they started building boats.
You might also consider looking at your spreader sweep. All the heavier teams down here have gone min sweep while the light teams are at max. The more sweep you have, the stiffer you can make the rig with shroud tension w/o inducing pre-bend. In other words - if you put the same rig tension on two boats, one is max rake, the other is min rake - the mast with max rake will have substancially more prebend.
Quote from: Darren Gilbert on June 06, 2013, 01:45:12 PM
Jeff - I will be at Chicago Noods this weekend and can measure 29,41,43,55,57 (Rondar Boats), 106 (Rondar UK) and 195 (Rondar USA...I believe). What is the reference point when doing this measurement?
Thanks Jeff.
I will measure from where the bow terminates to the centre of the hole where the forestay would attach.
I'll try to get as many boats as I can.
Cheers!
Darren
And good luck to ya! really nice work with the fleet up there, hear ol' 58 might be heading up to play sometime.
I still have your bunk, by the way
Quote from: Darren Gilbert on June 06, 2013, 02:02:17 PM
Thanks Jeff.
I will measure from where the bow terminates to the centre of the hole where the forestay would attach.
I'll try to get as many boats as I can.
Cheers!
Darren
Thanks Jeff. The Great Lakes fleet continues to grow each year.
Can you ship that forward trailer bunk up with #58? I believe it will be up here for the Sarnia One design regatta.
A couple of years ago, Eric and I measured 55 next to 119 and there was a difference on forestay mount distance from the mast. Can't remember exactly how much....but enough that he measured a couple of times..
Quote from: Darren Gilbert on June 06, 2013, 02:02:17 PM
Thanks Jeff.
I will measure from where the bow terminates to the centre of the hole where the forestay would attach.
I'll try to get as many boats as I can.
Cheers!
Darren
So if the older boats, the stem fitting is futher fwd than the new boats. Jeff buys Justin beer.
If the older boats, the stem fitting is further aft than the new boats, Justin buys Jeff beer.
Since Jeff drinks twice as much beer as Justin, I'm like giving him odds of two to one.
I'm feeling pretty good about this one. Its going to be better than my wager on the Pats vs the Giants.
3. Headstay (Forestay): Baseline setup suggests that for optimum helm balance (assuming the mast step is positioned as described above), the headstay (forestay) length should be 7571mm/298" (from the bearing point of the "T" tang to the bearing point of the lower pin).
Note: On Bennett built boats (hull #s under 69), the headstay chainplate is 20mm (.75") further aft. The above headstay measurements should be reduced by 8mm (.3") to compensate.
Straight from Brian's original tuning guide. Get your wallet out Justin.
Oh dear.
Jeff. Its on me.
Oh, I didn't even think to look at Brian's tuning guide. So Darren - make sure you follow what Ben said when comparing headstay lengths between boats.
don't worry Justin, I drink cheap beer.
Hi Guys. Steve Conger and I did some measuring on the weekend in Chicago.
Boats 29, 43, and 106 all head a measurement of 10 7/8" from the tip of the bow to the centre of the eye on the forestay.
194 was 10 3/8" from the same point.
Quote from: Jeff Jones on June 10, 2013, 09:37:45 AM
Oh, I didn't even think to look at Brian's tuning guide. So Darren - make sure you follow what Ben said when comparing headstay lengths between boats.
don't worry Justin, I drink cheap beer.
[/quote
Tecate if I recall. Can't get any cheaper than that! I recall you leaving a 12pk on my boat after a b-day regatta a while back. Took it home and sat in the garage fridge for quite a while as nobody would touch the crap. Of course it was next to the pacifico!
You socal boys are SO spoiled.
Quote from: Glenn Vanheel on June 10, 2013, 11:51:30 AM
Quote from: Jeff Jones on June 10, 2013, 09:37:45 AM
Oh, I didn't even think to look at Brian's tuning guide. So Darren - make sure you follow what Ben said when comparing headstay lengths between boats.
don't worry Justin, I drink cheap beer.
[/quote
Tecate if I recall. Can't get any cheaper than that! I recall you leaving a 12pk on my boat after a b-day regatta a while back. Took it home and sat in the garage fridge for quite a while as nobody would touch the crap. Of course it was next to the pacifico!
Bump for us noobies.
I have a Mark IV, and found this in the owners manual:
"Measure the forestay BS to BS (Bearing Surface to Bearing Surface) and lock
off the adjuster at 24ft 6"."
Both the Quantum and North guides specify 7588mm, which Google calculates to be 24'-10.75". North further specifies it should be within 1cm, or 4/10ths of an inch.
I sail Ullmans, and they indicate 52 inches using the arc method. Problem is the dog collar for the GNAV has rubbed off and moved the white marking tape, so I'm trying to get a better measurement for the entire wire.
Any suggestions/clarifications?? Thanks!
Fooking Walker...
Measure where someone else's white tape is and re-mark your mast.
Craig, go measure Timbo's turnbuckle length and duplicate. Headstays are all pretty close on the cutting table.
I'd ask Keith for a total headstay length. IME, using the arc method is great if you're 100% sure that the dude with the tape didn't have a couple of pints with lunch :-D
The bottom edge of the tape sits on the upper edge of the stainless goose neck bracket.
Go out sailing. Adjust the length of the headstay until you have a balanced helm (slight weather helm) with shrouds tight enough that mast is staying in column. That will be the right length for your boat with your sails.
Too much helm = tighten the headstay.
Too little helm = lengthen the headstay.
Thank you everyone for the all the great answers!
Hi all
Interesting reading about the head stay length, I'm really keen to find out if the mast foot on my Bennett boat (not sure of the hull number but GBR 602) is in the right place compared to the new boats. I don't have anything to measure over here in the UK so help would be really helpful.
I'd then like to figure out what the advantages/disadvantages are if my mast foot is in the wrong place?
We also race in an IRC handicap fleet, I'm looking into ways of barber hauling the jib in closer to the centreline so any ideas in this area would be good. We've tried using the lazy sheet, but its not great and for this type of racing where I'm not bound by class rules I wonder if there's a better solution?
Cheers
Duncan.
Duncan - Here's a way to check step location from one of the sailmaker tuning guides. It should be close and some folks might be slightly aft of this currently (1/2")
1. Check and measure the mast step position in the boat. Start from a point on the stern/deck intersection 7" to the side from centerline of the rudder tower. Make a mark on the deck. Then measure from this mark to the aft face of the mast (or to the forward side of the aft pin in the mast step if the mast isn't up). Measurement should be about (plus or minus ΒΌ"):
a. Bennett t ( Mk I) & Rondar Mk II boats: 148"
b. Rondar Mark III (sugar-scoop transom): 146 1/4"
c. Remember that the step fitting may not always be in the exact same place on some of the older boats. For example, many of the Bennett boats have had repairs to their steps and the fittings can end up reinstalled in a slightly different place.
Inhauling with the windward sheet actually works well for most of us. A general benchmark is to bring the clew in over the deck joint - until all are hiking and then back to normal sheeting.
Good luck
Dave N
Thanks Dave,
It could be a bit tricky for us to measure using the start point as described. We've installed the new rudder post moulding from Rondar, which over the existing transom.
Does anyone have the measurement from the front edge of the keel (when up) to the back of mast all at deck level, I assum the keel position has never changed?
Cheers.
Duncan, I seem to remember something like 17-18".. I will check. There is some play in the keel fore and aft when it sits on the trailer.
Thanks Tim, I'll have at look at ours over the weekend.
Works with old and new rudder tower. My old boat 18 made that transition. What's key is just measuring from the centerline off to a point 7" to the side,
Hello Duncan,
I have had a Pre-Rondar for a number of years.
With the switch to the carbon mast, the mast butt has to be moved considerably further aft. It required removing the mast track on the floor of the deck and moving it aft. Consider putting a thin plate underneath the mast track to spread the load and reduce compression of the floor under the mast. I will measure my mast butt position when I take the cover off. For me, it was a matter of trial and error as I played with the variances of rake and mast butt. If you like sailing with a more upright mast, you can move the butt a bit further aft, and the helm will balance with less rake. If you sail in a lot of big breeze, you could go one hole further forward from base and then add more rake to compensate. BUT this seems to open the jib slot and it seems you want a tighter slot, not wider. My guess is that you are sailing with a lot of rake to compensate for a butt that is too far forward.
As far as jib slot is concerned. I have seen a Viper put a second inboard jib track on for handicap sailing. I don't know how that worked for them. The jib slot in OD configuration is deliberately a little on the generous side to make the boat easy to sail.
I used to Barber Haul, IMHO, the most noticeable impact is that it adds twist to the jib and worked well to okay in light/light medium days in Marblehead's Atlantic swells. We don't barber haul any more. I think there are two reasons (I) The newer jibs seem to be cut a bit fuller and a bit more twisted up high and (2) I miss those long Marblehead rollers. Its all waves and chop for me nowadays.....Miami to Charleston to LIS .
BUT I will be at Marblehead in July for Race Week. Gawd, I love when the occasional Easterly cranks in because steering a Viper in big breeze down long Marblehead Atlantic rollers verges on the erotic!
Thanks Justin,
Some really interesting stuff there. We are currently using the old Ali rig for IRC racing and I've rigged up an eye on the the back of the mast that I run barber haulers from. Seems to work really well in up to 10knots, lots more height ( I'm sailing against J111's, J109, half toners and a few other IRC race boats) without hurting the speed.
We are still looking to sort the rake out though. I'm not convinced I've got it right, but I'd really like some base measurements to see where we are. By the sound of it my mast foot needs looking at, so any measurements (off the the front of the keel when lifted) would be great!
Oh one other thing, if you know anyone who's just bought a new a new kite and may have a good one kicking around I'd be really interested, put a big rip in ours yesterday!
Cheers
Duncan