UK-Cherub Forum
Cherub Chat => Tech Chat => Topic started by: Torchy on February 05, 2014, 10:54:30 AM
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Developments in the 18s have got me thinking again about reefing mains on Cherubs.
Many 18s now have the ability to put a reef into the small rig for 20kn+ conditions. It's more than the reduction in sail area, in fact it might be just as much about flattening the main even more and reducing the height of the centre of effort.
Quite a challenge for the sail designers.
Is anyone thinking along these lines? Clive has made some very pertinent comments about getting the boats we ask for ie currently a real handful in 20kn
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Is this more "rules" based than speed?
From the pictures googled, that does not look like a cheap lashed reefing point or something you'd shake out between back to back races. I'm sure one of the 18'ers will be along shortly to confirm how long/how many sails they are restricted to in a season and hopefully some better pictures.
Maybe the question is more are we as a group of owners/rule setters thinking about limiting rags? This would .certainly drive some people to think of zips, bundles, ties etc. whilst currently there is a trend for a cut down (often a "recycled" sail).
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my understanding is the 18s do this mostly to lower the centre of effort, from the races i have seen there has been little difference in raw pace and the racing is much similar to as a few knots less wind and everyone is on full size small rigs, lowering the centre of effort and reduced roach make a significant change to making the boat easier to control, especially in the windward mark bear away and down speed gybe drops, not something that cherubs struggle with the same as 18s i think i am right in saying that most modern boats flip the t-foil's angle of attack and point the nose down (generally) without problem and the spinnaker chutes rather than bags means dropping the kite is a much less risky zone in cherub sailing, still an interesting idea
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Best place to see them is the latest race on 18footerstv
Agree with Defender...it's a lot about the bear away in an 18 but they did not appear to pay a penalty in upwind speed. Not sure about downwind.
For us in Cherubs I think many feel they need a smaller main in high wind speeds and the ability to roll and zip up some of the foot and(?) flatten the main might produce a faster sail than a cut down main.
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I built a rig on my PlusPlus with a zip reef in the foot of the main and the mast telescoping down into the mast stump. It worked well enough as far as rigging was concerned, and you could put the slab in or take it out in a very few mins with the boat tied up to a pontoon - I even did it once without taking the main down although that would be foolish in breeze. However for some reason I never seemed to be able to get the boat in the groove upwind with the shortened rig. Of course this was a single sail rig. Having a jib in the mix would make it a lot more complicated.
Slab in...
(http://www.devboats.co.uk/plusplus/gallery/sr-bow2.jpg)
Note there's a set of points higher up for a really big chop down for nightmare conditions, but that didn't involve stumping the mast any further.
Slab out...
(http://www.devboats.co.uk/plusplus/gallery/int-aft.jpg)
The bearings and supports for the mast telescoping were a right pain in the neck to build because mast track had to disappear down the stump.
Something I've noticed in the past is that there are windy years and quiet years, windy decades and quiet decades. I haven't tried cross referencing this to trends in class rule changes!
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Pardon me for unlurking.... The 18s are allowed 2 rigs, i.e. 2xmasts, 2xjibs, 2xmains, 2xkites. Over the last decade their #1 rigs have grown hugely. Although they have always been limited by a max height the true mainsail and jib jib areas have grown a lot. In turn the #2 rigs have also grown so as to keep a sensible step between the 2 rigs. This has got to the point where the #2 rigs are close to the size of the #1 rigs of say 25 years ago. So now they are struggling to get the #2 rigs around the course in 25 knots. A related development is that the masts have got stiffer to support the big square-top (or even gaff style in some cases) mainsails. With a very stiff mast it becomes viable to reef the main as there are less issues with the luff curve, so they are now starting to regress to a reefing point on the #2 mainsail to lower the centre of effort. As has been pointed out, if your rules don't limit the number of sails (or number you can use in 1 event) then the only reason for adding a reefing point would be to keep the cost down.
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Pardon me for unlurking....
Completely welcome. Other views are always good.
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Hi Mike,
Don't apologise for unlurking...glad to have your input.
Cherub '2nd rigs' are about the size of 90s Cherub rigs (but 90s boats had a single wire) and 'full rigs' become a real handful somewhere between 20-25kn. I think many Cherubs have a 'full rig' which is below the allowable maximum of 15.5sqm. Some people have cut down old mains for 20kn+ which occasionally show up at events but these haven't been seen to give a clear edge in the sense of swinging any results that I know of.
Not sure exactly where the rules take us...I think there is a perception that someone using multiple rigs '...to gain advantage...' might make themselves unpopular and get voted down following a nationals in which this advantage showed. The main argument is cost.
I suspect a well cut reefing Cherub mainsail might confer an advantage come that 'windy year' and enable 15.5sqm rigs on boats sailed by lighter crews in more moderate conditions but developing the 'cut' would be the issue. You might get neither one thing nor the other ie a slower sail in moderate winds and no advantage come the heavy stuff.
I can think of 2 or perhaps 3 crews who are competitive up to 14kn or so who feel they can't keep up once it gets more windy.
Cherub masts have pretty fixed bend...certainly I never see Loco's uppers loosening and they have no adjustment.
Watching what happens in the 18s will be interesting.
btw on the question of design I suspect the use of a zip is counterproductive. I think Velcro might be better enabling a 'footline' analogous to a leechline to be used. This might enable more control of the shape in conjunction with the outhaul.
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I have a really hard time buying into the cost argument against having 2 sets of sails.
The upfront cost is clearly higher but total cost of ownership does not increase - unless you are one of those people still clinging onto 10 year old rags and wondering why you cant go upwind anymore. Most people with small sails have recut older sails at limited cost, and those buying purpose built second mains are likely to be those who would be buying new sails to stay competitive anyway.
The combined usable life of 2 sets of sails cut for their purpose will be greater than simply replacing your 'main' set a few years down the line.
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"Cherub masts have pretty fixed bend...certainly I never see Loco's uppers loosening and they have no adjustment."
In my experience, the leeward upper becomes pretty slack upwind in anything more than about 15 knots. As you wang on enough cunningham to ignite the mast tip then it will almost always go slack to the point of waving about when you are applying sufficient mainsheet tension. Letting the kicker and cunni off at the windward mark before the bear away will load the uppers back on again to control the mast tip with the added kite loads.
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I too think that it is a false economy trying to put reefing points in.
The reefing system will also cost.
We have a small main that we use about 10-15% of the time (QM and Weston this year).
I suspect that using it on those days has halved the degradation of the big main.
Because the racing is not close on small main days you can tolerate a sail that is knacked or other wise compromised by having being adapted from something else. The Peter's old RS200 main did the job and was effectively free.
The issue of people not using full size rigs is potential a thorny one.
A number of sails have been measured significantly smaller than the sail makers software suggests they should be. Including ours. I have more confidence in the sail makers software than our measurement process.
It is the intention of our rules to accurately measure main and jib areas.
I believe that there are boats with full size rigs that have been measured small and boats with rigs that have measured close to full size that are probably over sized.
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Loco's main rig is under 15.5sqm. I measured it in compliance with the ISAF measurement handbook using triangulation and extrapolating rounded corners as directed. As I recall it was about 14.5sqm. I would have to do it with help to be sure exactly how far under it is.
I don't see how the reefing system will add significantly to the cost of a new sail.
I am (as previously) more persuaded by the 'having a second main saves you money on the bigger mainsail' argument. However, as I recall Matt Kiddle, when measurement officer, felt that someone could potentially protest against someone who used multiple sails within a series to 'gain advantage'...and why else would one do it?
As I recall the previous discussion ended inconclusively.
Were I to order a new suit of sails or start a new build I'm not sure what I would do.
btw Tim - Loco must have a particularly stiff rig
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btw Tim - Loco must have a particularly stiff rig
...or perhaps you just dont have a Noyce to apply your cunningham?
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For the record, the measured areas I have on file for your Fyfe sails Nigel is 15.05 square metres.
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I don't think that the discussion was inconclusive.
The consensus was that most active boats now had second sails and that these had not added significantly to the costs but did allow people to keep racing in conditions where they otherwise would not and that there was therefore no need to change the rule that currently has no restrictions on the number of sails.
It was however felt that we should keep the kite measurement rule even though it is problematic as we do not want people building monster light air kites.
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I think any rule to restrict sails would need to be a class specific rule written into sailing instructions on a regatta by regatta basis (or standard class S.I's). IMHO reefing sails will not work on a 05 cherub as the mast bend at the top of the rig means that as the sail comes down the track it will no longer fit the curve and will pull out of/break the mast track. A second sail is the only practical option of reducing sail area.
As others have stated the TCO over a number of years is no higher than having a single well maintained suit of sails. In fact I suspect it is lower as people are prepared to tollerate a more 'blown out' high wind sail. A single sail that is used across all conditions needs replacing more frequently as I can attest (hence why we had a spare RS200 main to use as a cherub small rig). In fact most serious 200 sailors have a high wind (older) sail and a newer sail for all other conditions. In effect a 2 sail programme designed to prolong the life of your best sail.
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Good point about the mast curve...
Is the consensus that as a class we feel that a second (smaller) main for heavy airs is within the spirit of the rules? I feel that the previous discussion was inconclusive. I thought that a challenge was possible under the '...can't change gear unless damaged...' clause.
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btw Tim - Loco must have a particularly stiff rig
It doesn't
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I would love to restrict to 1 set of sails as that would bring the balance away from favouring lighter crews. It annoys me watching everyone planing past twinning whilst I am still very much in displacement mode and then still be right up there when the wind gets stronger. Allowing 2 sets of sails does not encourage people to be moderate with their no1's. I think we might see some closer racing in lighter winds if people were encouraged to use sails appropriately sized to their weight and skill in all conditions.
That said, it is useful to have an old set of sails for when it is really windy, just from a longevity point of view.
Edit: I am in no way trying to make up excuses for my lack of speed in light winds here. (I know I appreciate a plate of food and could sail better)
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You've just made a good argument for a rule change Ben...then reefing sails might become the norm...and why not?
Matt - maybe I need to yank that Cunningham harder then
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If 2 suits of sails were banned all the 05 boats who wished to reef would need new masts or an ingenious way of reefing.
Ben, frustrating as it must be in my opinion banning 2 sails will see participation in the class drop. Having 2 sails gives more people the ability to sail in a greater range of winds. It is also safer as it cuts down on capsizes/physical exhaustion. Jill just isn't strong enough to handle a full sized main for an open meeting day in 20knts. She can manage a cut down one. If the rule was implemented it would mean we could not safely race a cherub in 18plus knts therefore would not go to opens with this forecast or I would turn up with a bloke (which BTW would be much quicker round the track than Jill and I am with small sails).
Surely as a small class we want to be encouraging participation not thinking up rules that limit when people can race.
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Note for all non-cherub sailors reading this thread.
Due to current adverse weather conditions there are a number of forum members who are currently suffering from "3-sail"withdrawal.
Symptoms include restlessness, grouchiness and a tendency towards long discussions about rule changes...
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The counter argument to that is that you should have smaller sails then so you can manage with one set in both the light and the windy stuff thereby normalising for weight.
I feel there might be a lot of slightly bigger teams who would be attracted to the class if they stood a chance of winning something no matter the conditions. (not that that is the only factor in that). Allowing 2 suits of sails makes it pointless me turning up to light wind events because I am always going to be beaten by a light crew with massive sails.
I have no intention of banning it, I was just voicing the other point of view.
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One of the biggest flaws of a modern Cherub is that it works really well over quite a narrow wind range.
Having 2 sails goes some way to solving this without adding significant cost.
If banned we would look at a mast reefing system similar to an RS 600 and similar to the system that we used to run on the B18s where we had 2 rigs with one mast and one main.
I suspect that it would be more complex and more costly.
Forcing people to use the same sail for a whole regatta would not make the light weights develop more moderate sails.
Most racing and the closest racing is done in lighter winds. You cannot afford to give up a competitive advantage for the small number of days when you would otherwise have used small sails.
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Of course the heavy weights do have the option of bigger sails in the light winds. They are just attached to a bigger boat - called an International 14 ;D
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or an 18.
both though mean less people in the class
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A good thread this. Thinking laterally, again, if the discussion is moving towards sail size and crew weight, as Ben has mentioned, perhaps the class could look at a overall weight system. Boat and Crew weight = a Max sail size measurement. (I am sure this has been visited many times before). Could it help to aid a more level playing field? A way of improving the handicap heavyweights have in light air competition.
(I believe this is what the 300 A & B rig systems were supposed to do. Clive will be the expert on this)
When we talk of rules though... As a development class, if the rules evolve to restrict the amount of sails used at events then we will be restricting more ideas and the development of the rigs. The up-side of this topic is that more second-hand sails could be available for the older boats to keep going if any amount of sails are allowed, as is now.
But most importantly the factor for this discussion could be how to keep the heavyweights in the class? or how to attract heavy crews? Could the 12 foot platform be designed with a variable rig configuration to do this better?
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I am for having a second mainsail but I am concerned that the logic of this is easily extended to a second jib (no brainer really, they wear out quickly) to suit the smaller mainsail and a second very flat cut kite and all 3 sails would be used together above, say 18kn.
I did wonder if reefing mains might be a solution and they might be, however I think just having a second main makes sense in many ways eg cost and ease of use.
I think the use of two complete sets of sails would be stretching the current (laudable) laissez faire.
...and yes, Roland I'm suffering from 3 sail withdrawal...well 3 Cherub sail anyway - I was sailing a beautiful clinker built yawl last weekend in a force 6-7 ;D (very big smile)
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An interesting debate regarding smaller sails.
Our small mainsail is only about 1m2 less in area than our full size one, all the area is taken out of the head, it is cut slightly flatter than our full size main, and is matched to the luff curve of the mast. It is not the only change we make when it's windy, additionally we rake the rig back by 2-3", this helps with the balance of the boat and also opens the leech of the jib depowering that as well, we also ease the uppers (from max power setting) to allow the mast to work a bit more upwind, but not too much for the mast to go over the front downwind. The advantages of the small main are less drag upwind, slightly easier at low speed manoeuvres (start, kite hosts/drops ans tacks) and finally it's quicker to right from a capsize. I don't think its make much difference on the bear away as the t-foil does all the work for us. Note we won the light wind race at the inlands at QM with the small mainsail against a majority of full size sails.
It certainly has saved some wear and tear on the full size main which has now allowed us to go to a lighter cloth saving weight and some money.
There is no reason that the heavier sailors couldn't develop a more powerful rig to increase their light wind performance, stiffer masts, fuller sails, more upright rig, put this on a hull that carries weight a bit better and I would imagine that any performance deficit could be greatly narrowed.
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Of course the heavy weights do have the option of bigger sails in the light winds. They are just attached to a bigger boat - called an International 14 ;D
Lightweights have the option of smaller sails in heavy winds. They are attached to a smaller boat - called a Topaz ::)
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or a 200. I think that they are quite similar.
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I think that different rig setups and sail shapes are the way forward as it reduces complexity however it is a more costly situation.
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After todays sail in Spanish I now a have a storm jib
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After todays sail in Spanish I now a have a storm jib
... and some very stylish hankis???
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Sounds like you have developed an automatic reefing system...ooops
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Ben you also need to factor in that your hull is known for being slow in light winds. The lee's built the e5 and Paul the E6 to try and get better performance when the wind was lighter. That said she is still one of the fastest boats out there in a breeze. I think the cost argument for two suits is a non starter, most of the active fleet now have them and if you look at the wide and varied hull and rig options from early boats to newer ones it's all down to cost. A second main costs less than a second lifting foil, but we are a development class, if people want to sail a one design there are a shed load to choose from. Having sailed 29ers they are not all as even as the manufacturers would like us to believe.
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A link to the creation of the storm jib: http://www.youtube.com/watch?v=RECisBnxxdQ&feature=youtu.be
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Nice
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Not just us who are having this fascinating discussion.....
http://www.yachtsandyachting.com/forum/forum_posts.asp?TID=11338&title=reducing-sail-size
I haven't read it all but early concensus is smaller sails in bigger winds is a sensible approach
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Hmmm...it is quite complex isn't it?
I think our current consensus (as I understand it) of encouraging a small main but discouraging going further stands up well. No need for more rules and if someone wants to challenge the consensus they can.
Part way down the thread the spectre of multiple sails becoming multiple rigs was raised...apparently it saves money in the long run because your other gear doesn't get thrashed (where have we heard that before?)...but then of course your light wind rig/sails can be made very light to great advantage...and last 10 mins.
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Matt - maybe I need to yank that Cunningham harder then
⇧ This, reminded me of this ⇩
Draft too far aft in a main sail = not enough cunningham
Battens hard to pop in a tack = not enough cunningham
I suggest you wind some batten tension back on and give the cunno a yank.
Loco's cunno cleat location never made it the easiest to adjust, maybe this needs addressing?
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Yes, I think that is the issue Tom, that and worn out cam cleats which sometimes let go. I'm thinking of bringing the Cunningham right back to the transome where it will be next to the rudder T-foil purchase.
I'll see if leaving the kicker where it is works - it's easier to get to than the Cunningham.
Screw-type batten adjustment has solved the batten popping. I have easy adjustment of (particularly) upper batten tension and getting them to pop is easy and largely independent of Cunningham ie very light weather I slack them off a bit and can choose my Cunningham tension. If I can get out sailing enough I'm hoping to try soft-ish tension on battens at the top and see if the leech will release at the top in gusty conditions. Sam and I are still on the light side and I think would benefit from this.
Much of the issue for us though is simply practice time. I get out more than Sam but still not enough and Sam is still a bit wedded to his Xbox.