Print Page | Close Window

GNAV v's Kicker

Printed From: Yachts and Yachting Online
Category: Dinghy classes
Forum Name: Dinghy development
Forum Discription: The latest moves in the dinghy market
URL: http://www.yachtsandyachting.com/forum/forum_posts.asp?TID=4639
Printed Date: 28 Mar 24 at 2:17pm
Software Version: Web Wiz Forums 9.665y - http://www.webwizforums.com


Topic: GNAV v's Kicker
Posted By: G.R.F.
Subject: GNAV v's Kicker
Date Posted: 11 Sep 08 at 12:58pm
Now one of the burning reasons for returning here and potentially facing
another firestorm was because of this question which has been vexing
me. After travelling the best part of 40 miles without one how effective is
a GNAV really?

Now I haven't had a great deal of experience of conventional kickers, my
Laser 3000 had one, but the Musto had a wiered cantilever thing and the
RS and my Alto both have Gnavs.

I am wondering, if the GNAV actually does the job that the original kicker
came about to do as well as it did.

So to refresh my recollection of how kickers came about some old boy
noticed without one, the older style sails would lift the end of the boom,
collapse the leech, more air escapes than required, boat slows down, or
more the reverse of that, he found by additionally pulling the boom down
it kept the leech tight when required, or so I assume I forget who it was,
some wooden masted boat it was that long ago and he won by quite a big
margin.

We used to mess about with boom vangs in the early days of windsurf
racing when we had no full battens and CYT sails, but they made no
appreciable difference and along with topping lifts got left in historys
wastebasket.

The thing that appears to happen that is different with a GNAV, is the
bending of the lower mast section, I must admit it was more pronounced
on the RS than it is on the stiffer mast of my current ride, but it is still
there just the same. The effect this has, is to both flatten the sail and
narrow the entry at that point of the foil, making it shallow, so rather
than just powering up the sail with a tighter leech whilst retaining a nice
deep foil, it has the opposite effect.

So that's just my perception, I'm wondering if anyone else has any recent
experience of both systems, I'm almost of the view that having both
would be beneficial. O.K. Jumanji might have to divert his stampede and I
realise that is a bonus for lots of boats.

But does this happen? Do other craft combine both, Does anyone else
feel the GNAV aint quite as effective as a full blown kicker system..

Am I placing to much importance on it, it's all you hear folk talking about,
kicker this kicker that, is it boat park rhetoric?



Replies:
Posted By: Merlinboy
Date Posted: 11 Sep 08 at 1:04pm
I prefer conventional kicker systems, personally i find Gnavs a bit clumsey.  I have never seen a boat with both and dont think there would be any benefit.  I know that some of the 14 fleet are moving back from Gnavs to convensional kicker systems.why dont yyou rig up a kicker system grumpf and trial it.  The only disadvantage i can see is it gets in the way of the crew a little.

-------------


Posted By: G.R.F.
Date Posted: 11 Sep 08 at 1:29pm
I don't think I can, the boom would probably fall off the way it's cobbled
together right now, round gooseneck into a square hole, but I have been
thinking about it adding one in parallel, amazing how having to sail without
anything focusses the mind.

Well an here's another redundancy, it's rear sheeted, in fact the sail is
hopelessly inefficient unless I'm almost block to block it's that slack leeched.
(There again if it hadn't been this year we'd have stayed on the shore).

So you really need the Gnav to be functioning if you want to sail sheeted out
or your left with a flogging mess where the main should be..


Posted By: tmoore
Date Posted: 11 Sep 08 at 1:54pm

i think you right about the GNAV on the 500. it does seem to bend the lower mast rather a lot. i countered this by using a fair amount of rig tension and pretty tight lowers to reduce that bend. i also found the system needs a bit of fiddling to get the right range of play needed for different wind speeds.

HOWEVER the GNAV on both the 300 and 29er are much better. the 300 one is slightly different in that it slides (rolls) on the mast. i think the reason it works on these 2 boat is simply because the lower masts on these boats are that much stiffer than the rs500.

i personally feel that in the breezier stuff GNAV's are better because they reduce the chances of being caught/ trapped on anything (possibly safer) and give you much mre space to move from side to side. in the lighter stuff then it just makes it more comfortable to sail (for the crew). on the other hand, will it make that much difference on a singlehander? how often are you that close to the mast? and is the extra space worth the extra complication and cost?

one thing a GNAV does is change the way you would use kicker.

sorry to digress but i actually dont know what GNAV means, can anyone fill me in?

russ, do you know why the 14's are moving back to the conventional kicker?



-------------
Landlocked in Africa
RS300 - 410
Firefly F517 - Nutshell
Micro Magic RC yacht - Eclipse


Posted By: MikeBz
Date Posted: 11 Sep 08 at 1:58pm

A conventional kicker produces a forward thrust at the gooseneck which is proportional to the amount of kicker tension (thus proportional to the leech tension) which induces bend (there may be strut(s) or lower(s) to counteract it).  The kicker pulls back at the heel of the mast with a similarly proportional force, but because it's at the heel it has no effect.   So put simply, more kicker equals more bend trying to be induced at the gooseneck.

A gnav swaps these 2 forces over - the forward thrust is induced further up the mast where the hardware meets the mast.   This is countered by the boom being thrust backwards with a similarly proportional force.  In this case the backward force on the boom (which presumably is bolted to the gooseneck in some way otherwise it would just fall off) will to some extent mitigate the forward force at the top of the lever.  In practice this 'push-me-pull-me' act some way up from the heel of the mast will be trying to induce an S-bend - imagine you've got a long whippy cane, both ends clamped, and then you get hold of it with both hands and pull with one hand whilst you push with the other.

I would have thought from the above that the gnav would induce less bend, albeit subject to positioning of struts/lowers/gooseneck/heel etc.  That's an intuitive guess rather than an engineering/mathematical proof - although it wouldn't take too much of an engineer to come up with the proof (or otherwise).

The only boat I've sailed with a gnav is an RS300 - it's the best kicker system I've ever used.  It automatically gears - the more tension you've got the more purchase you have due to the way the angle of the lever changes as you wind it on.

Mike



Posted By: IanW
Date Posted: 11 Sep 08 at 1:58pm
Gnav is vang backwards or upsidedown


Posted By: Jack Sparrow
Date Posted: 11 Sep 08 at 2:22pm
You could try one of these.

A Temple vang. No funny mast bending to deal with and improved room in the cock pit. Less blocks / wire etc
.


-------------
http://www.uk3-7class.org/index.html" rel="nofollow - Farr 3.7 Class Website
https://www.facebook.com/groups/1092602470772759/" rel="nofollow - Farr 3.7 Building - Facebook Group


Posted By: G.R.F.
Date Posted: 11 Sep 08 at 3:04pm
O.K. Jack, you've got my total and undivided attention..

Where should I stick that?

Er that's without bending over thanks.




Posted By: craiggo
Date Posted: 11 Sep 08 at 3:12pm
GRF,

The temple vang is basically a prodder extending out of the back of the foredeck. The kicker is then attached in a vertical plane between the prodder and the boom. In theory this only increases leech tension without all the lower mast bending. The picture shown by Jack shows the prodder on the mast stump.

However there are drawbacks with the temple vang. Sometimes it is desirable to induce bend in the lower mast. For this reason the Scorpions experimented with having both a conventional kicker and a temple vang.

I have to say though I reckon there is more chance of snagging yourself on the prodder than there is of getting caught by a standard kicker.

Alternatively GRF, you could fit your boat with a full width cockpit traveller and then you'd only need the kicker for downwind work. Sheet the main on hard upwind to control leech tension and play the traveller!


Posted By: iwsmithuk
Date Posted: 11 Sep 08 at 3:19pm

Originally posted by craiggo

GRF, 
Alternatively GRF, you could fit your boat with a full width cockpit traveller and then you'd only need the kicker for downwind work. Sheet the main on hard upwind to control leech tension and play the traveller!

So, like a catamaran then.

And you're suggesting this to GRF!

 



Posted By: tgruitt
Date Posted: 11 Sep 08 at 3:40pm
Originally posted by craiggo

GRF,

The temple vang is basically a prodder extending out of the back of the
foredeck. The kicker is then attached in a vertical plane between the
prodder and the boom. In theory this only increases leech tension without
all the lower mast bending. The picture shown by Jack shows the prodder
on the mast stump.

However there are drawbacks with the temple vang. Sometimes it is
desirable to induce bend in the lower mast. For this reason the Scorpions
experimented with having both a conventional kicker and a temple vang.

I have to say though I reckon there is more chance of snagging yourself
on the prodder than there is of getting caught by a standard kicker.

Alternatively GRF, you could fit your boat with a full width cockpit
traveller and then you'd only need the kicker for downwind work. Sheet
the main on hard upwind to control leech tension and play the traveller!


Just to correct you, that's the boom the temple vang is on in that picture
not the mast. Its on the mast end and points downwards. It is then pulled
in towards the front bulkhead with a pully system, they are great for
crews, and pretty powerful too, just need to make sure they are very very
strong!

-------------
Needs to sail more...


Posted By: G.R.F.
Date Posted: 11 Sep 08 at 3:54pm
Woah steady..

You've got the irish man in the dustbin, slow down on the telling him to pee
in the corner..


Full width cockpit traveller? Pickies? What boat would have one of those.
What exactly travels on it, all my ropey bits hang off the back of the boom.

I'm sort of visualising the temple vang so does the bit stick in front og the
mast would it not intefere with my self tacking jib?


Posted By: tgruitt
Date Posted: 11 Sep 08 at 4:01pm
If someone can tell me how to put a picture here on a mac, I have a great pic
which explains all!

-------------
Needs to sail more...


Posted By: Chew my RS
Date Posted: 11 Sep 08 at 4:24pm


-------------
http://www.sailns14.org - http://www.sailns14.org - The ultimate family raceboat now available in the UK


Posted By: G.R.F.
Date Posted: 11 Sep 08 at 4:25pm
You need to get the shot uploaded onto another site then post a link. In
that
image box, I dont expect this programme will upload stuff from a mac
desktop.

If it's a long link, see the little arrow in the bottom right corner of the box
you type in drag that to the right so there is no line break in the image
formula.

If that fails email it to me I'll bung it up for you.

This forumware isn't that Mac friendly but there's usually a work around.

Edit: Thanks Chewbacca I get it now...


Posted By: aardvark_issues
Date Posted: 11 Sep 08 at 7:24pm
I've never had problems uploading pictures from a Mac...


Posted By: craiggo
Date Posted: 11 Sep 08 at 7:42pm
Thanks for correcting me Tom, I assumed that the pic was the mast stump as it didnt look very long.

The arrangement I mentioned was however used in the Scorpion.


Regarding full width travellers, you only tend to see them on cats and in monohull singlehanders such as the OK, but if the boat is beamy enough it could work in a doublehander. In fact if my memory is correct didnt early 420s and 470s have a traveller ?


Posted By: Medway Maniac
Date Posted: 11 Sep 08 at 8:54pm
Originally posted by MikeBz

A conventional kicker produces a forward thrust at the gooseneck which is proportional to the amount of kicker tension (thus proportional to the leech tension) which induces bend (there may be strut(s) or lower(s) to counteract it).  The kicker pulls back at the heel of the mast with a similarly proportional force, but because it's at the heel it has no effect.   So put simply, more kicker equals more bend trying to be induced at the gooseneck.

A gnav swaps these 2 forces over - the forward thrust is induced further up the mast where the hardware meets the mast.   This is countered by the boom being thrust backwards with a similarly proportional force.  In this case the backward force on the boom (which presumably is bolted to the gooseneck in some way otherwise it would just fall off) will to some extent mitigate the forward force at the top of the lever.  In practice this 'push-me-pull-me' act some way up from the heel of the mast will be trying to induce an S-bend - imagine you've got a long whippy cane, both ends clamped, and then you get hold of it with both hands and pull with one hand whilst you push with the other.

I would have thought from the above that the gnav would induce less bend, albeit subject to positioning of struts/lowers/gooseneck/heel etc.  That's an intuitive guess rather than an engineering/mathematical proof - although it wouldn't take too much of an engineer to come up with the proof (or otherwise).

Agreed, Mike, up to the point where you say "the gnav would induce less bend".

With a conventional kicker you can use a ram or lower shrouds to effectively lock the gooseneck in position, so that the only effect of the kicker is to apply leach tension. With a gnav, sure you can lock the position of the attachment point of the gnav on the mast in a similar manner, but to prevent bend you also need a system to stop the gooseneck moving aft, inducing bend. Some sort of puller or second ram at gooseneck level would do it, but I've yet to see it, and do you really want two arrangements to manage?

On the 3000, the gnav brings big benefits in terms of crew space - especially welcome in light airs - but it comes second to a conventional kicker in terms of mast bend control, imho.

I'd actually already considered using the composite kicker-gnav system proposed by GRF, which could be rigged such as to remove the aft pull at the gooseneck and the attendant bend (effectively you'd be pulling the gnav slider from the heel of the mast instead of from the gooseneck). Use the combo in a blow when mast bend control is critical and remove the kicker in light airs when space is more important. But so far, it's seemed like to much faff - deficiencies in my sailing are far more significant than any minor gains achieved, but for top sailors maybe something to consider.



-------------
http://www.wilsoniansc.org.uk" rel="nofollow - Wilsonian SC
http://www.3000class.org.uk" rel="nofollow - 3000 Class


Posted By: G.R.F.
Date Posted: 11 Sep 08 at 10:02pm
I'm not a top sailor by any stretch of the imagination, but I do know what i
want out of a sail in any given wind condition, and the only way I can see
that occurring, without having on the fly mast bend and rake control like
we have on racing sailboards, is to have both options.

Some times I might want tight leech fat belly and not worried about a
little steeper entry and other times I might want the sail flattened, fine
entry tight low end, twist up top, it just makes me feel better if the sail
looks right.

I have noticed this mast ram thing on old five ohs and wondered if that
were sited directly in opposition to the Gnav, but then I'd be worried
about crushing the mast with opposing forces.

There's a lot of food for thought here and it's encouraging to read others
may be having 2nd GNAV thoughts also.

No joy with any pics of something with a cockpit wide traveller?

Interesting discussion though..


Posted By: Neal_g
Date Posted: 11 Sep 08 at 10:12pm

mast rams appear on fireballs as well as 5ohs and the main reason is instead of chocks to stop the bottom of the mast moving a lot of the newer fireballs have gone for chocks again and a puller for down wind to stop the mast inverting.

as for GNAVs they bend masts lots, but so will kicker usually the difference with gnavs is that they are loading the mast above the goosneck at one single point theis is usually supported by lowers the the same point the gnav hits the mast as on the laser 4000, either way works but i prfer kicking as it provides entertainment when the crew goes full on into it during high speed wire to wire tacks



-------------
(Redoubt Sc)
Miracle 4040
GP14 13407

Crewsaver phase 2 range now available to buy online on at http://www.gibsonsails.com


Posted By: neilw
Date Posted: 11 Sep 08 at 10:37pm

are you talking about the type of traveller on the Finn - also used by OKs and FDs. If so here's one on my Finn



-------------


Posted By: MikeBz
Date Posted: 11 Sep 08 at 10:57pm
Originally posted by Medway Maniac

Originally posted by MikeBz

A conventional kicker produces a forward thrust at the gooseneck which is proportional to the amount of kicker tension (thus proportional to the leech tension) which induces bend (there may be strut(s) or lower(s) to counteract it).  The kicker pulls back at the heel of the mast with a similarly proportional force, but because it's at the heel it has no effect.   So put simply, more kicker equals more bend trying to be induced at the gooseneck.

A gnav swaps these 2 forces over - the forward thrust is induced further up the mast where the hardware meets the mast.   This is countered by the boom being thrust backwards with a similarly proportional force.  In this case the backward force on the boom (which presumably is bolted to the gooseneck in some way otherwise it would just fall off) will to some extent mitigate the forward force at the top of the lever.  In practice this 'push-me-pull-me' act some way up from the heel of the mast will be trying to induce an S-bend - imagine you've got a long whippy cane, both ends clamped, and then you get hold of it with both hands and pull with one hand whilst you push with the other.

I would have thought from the above that the gnav would induce less bend, albeit subject to positioning of struts/lowers/gooseneck/heel etc.  That's an intuitive guess rather than an engineering/mathematical proof - although it wouldn't take too much of an engineer to come up with the proof (or otherwise).

Agreed, Mike, up to the point where you say "the gnav would induce less bend".

With a conventional kicker you can use a ram or lower shrouds to effectively lock the gooseneck in position, so that the only effect of the kicker is to apply leach tension. With a gnav, sure you can lock the position of the attachment point of the gnav on the mast in a similar manner, but to prevent bend you also need a system to stop the gooseneck moving aft, inducing bend.

Well to be fair I did say "subject to positioning of struts/lowers/gooseneck/heel". But you're right, I didn't consider the inversion that you'll get below the gnav if you have lowers at that point preventing the mast from going forward. As you say that inversion will cause some forward bend above the lowers, but IMO it will be very little - go back to my example of grabbing the mast with both hands and doing the push/pull thing with say 12-18" between the 2 points.  Without lowers or strut I still think the gnav will induce less bend than a conventional kicker on a keel-stepped mast (hence a fair distance between the heel and the gooseneck).

Mike



Posted By: Merlinboy
Date Posted: 11 Sep 08 at 11:16pm
Originally posted by neilw

are you talking about the type of traveller on the Finn - also used by OKs and FDs. If so here's one on my Finn

 

Fook me i want one!!! 



-------------


Posted By: JimC
Date Posted: 12 Sep 08 at 12:04am
Originally posted by neilw

are you talking about the type of traveller on the Finn

*That's* not a wide traveller... *This* is a wide traveller...


(apologies for the photo credit YY)

Personally I'm no fan of the push kicker* because it messes up one of the more effective bits of sail, puts bend in the mast where I really don't want it, and needs extra long lowers (=more drag) to try and stop it doing so.

As someone who's always sailed forward hand I don't really buy the space thing.


*I refuse to use the vile V "word"


Posted By: craiggo
Date Posted: 12 Sep 08 at 8:16am
Perfect illustration Jim,

Come on then Graeme get one of those on your Alto, it'll give Jumanji something to smash his shins into !!



Posted By: Iain C
Date Posted: 12 Sep 08 at 8:24am

I too am a big fan of the temple vang.  Nice and simple, more room for the crew, and all the purchases can be hidden up the side of the centreboard case.  However I could only really see it being light, strong and practical on a carbon boom, I guess you could weld one up in alloy but I would not give it long and it will probably weigh a ton.  If made in carbon, it must be done right, as in VERY strong, and at just the correct angle, as it's easy to get it wrong and go "block to block", especially if you have a raking rig.

You can just see one here on this 12.  The white part of the mast up to goosneck height is not mast, it's actually part of the hull, it's called a stump and it's completley devoid of any support such as lowers, and has not broken yet despite our best crashing efforts!  The vertical member near the gooseneck is in massive compression and the member sloping back is in tension although obviously does not have to be as strong as long as it's well attached to the boom.



-------------
RS700 GBR922 "Wirespeed"
Fireball GBR14474 "Eleven Parsecs"
Enterprise GBR21970
Bavaria 32 GBR4755L "Adastra"


Posted By: Jack Sparrow
Date Posted: 12 Sep 08 at 8:24am
Originally posted by tgruitt

If someone can tell me how to put a picture here on a mac, I have a great pic
which explains all!


Use Firefox as a browser. Seems to be good for me.

I will report back on my 'temple vangs' strength when I finally get the thing on the water. But I am sure Aardvark Issues will vouch for it's strength, it was made by his sister company - Aardspars. ( or should I say farther company?)


-------------
http://www.uk3-7class.org/index.html" rel="nofollow - Farr 3.7 Class Website
https://www.facebook.com/groups/1092602470772759/" rel="nofollow - Farr 3.7 Building - Facebook Group


Posted By: G.R.F.
Date Posted: 12 Sep 08 at 9:03am
Originally posted by Iain C




I must just say, is it me or is that a fabulous spinnaker, dunno what it is
about the shot, the lovely curve of the luff or the radial clew but that has
to be the nicest spinnaker I believe I've ever noticed.

Makes ours a joke by comparison.

Anyway back on topic, I think the guy developing the Alto would totally
freak if we asked about a traveller like that, but I can see the benefit, we
also have this big hoop thing in the middle of the boat like the rs400 yet
it's sheeted aft. I did ponder the thought of an aft traveller running over
and above the stick tiller thing so the damn sheets don't keep wrapping
themselves either around the stick handle or the corner of the stern at
the most inopportune moment.

We've already changed so much, I worry he'll lose what patience he has,
he's concerned about the class not becoming like the 505's and pricing
and complicating itself out of the market.

I can fully sympathise, given my own confusion even a few months ago I
would have looked at that Finn and the brain would have short circuited
and I'd have had to walk away in frustration simply at the lack of
understanding of what all the ropes do. Now here I am actively looking to
complicate things further against all my prejudices regarding such
complications, races are after all won and lost more on sailing tactics and
ninety percent of that on the start, than any complicated setting or
adjustments has always been my opinion. You can lose more places
fiddling with an adjustable outhaul or downhaul than you'll ever regain up
a beat or down a reach for the difference such adjustments make.

But it's such a delightful temptation with a boat where you don't run
quite the risk of falling in, having a fiddle and the trauma of that distance
race has changed my view - I think.


Posted By: craiggo
Date Posted: 12 Sep 08 at 10:05am
Graeme, get rid of the hoop, as you say if you have a bridled mainsheet onto the transom which is then led along the boom and down into the cockpit there is no need for a hoop.

Regarding the scorpion kickers system I mentioned previously I cant find any photos but here is a sketch (sorry for the lack of artistry its an MS Paint special), effectively a temple vang mounted from the foredeck rather than the boom. wire from prodder to cockpit sole/bulkhead junction ensures that prodder sees no bending only compression. THe prodder is only pinned to the back of the foredeck to allow it to rotate laterally with the boom.



Posted By: JimC
Date Posted: 12 Sep 08 at 10:27am
Note that I'd never use a traveller these days: the old girl only has it because that's how she was built and its also structural. The transom bridle is my preferred solution. I can envisage using a *kicker* on a radiused track, as some leadmines do, but there are formidable engineering challenges. One solution for the bridle/transom corner thing is a bit of shock cord as per 29er/49er.

Temple Vang *and* a stump Iain! I guess I can see why, but I'm not comvinced. Although I'm still in two minds about the temple vang thing anyway: I'd like to see an actual engineering analysis of where the loads go...


Posted By: Merlinboy
Date Posted: 12 Sep 08 at 10:32am
I cant see any benefit in the scorpion system over a normal vang! Will it not just weigh more??

-------------


Posted By: Skiffybob
Date Posted: 12 Sep 08 at 10:49am

Well I guess the advantage is that it pulls the boom vertically down without pushing the boom forwards at the same time and bending the lower mast.

It looks like it might take up even more cockpit room though, so I guess it would only be practical in a fairly long and roomy boat.



Posted By: Merlinboy
Date Posted: 12 Sep 08 at 11:08am
also how does it pivot when you tack/gybe? surely with any real tension it would lock the boom off (like a mainsheet)

-------------


Posted By: G.R.F.
Date Posted: 12 Sep 08 at 11:30am
I use shock cord Jim, but even that on rare crisis occasions like the kick
up rudder jamming shortly after launch as the bit of cord that operates it
jams between it and the sides and we have to dismantle the whole thing
yards from a lee shore break that would trash us, then is exactly when
the rope curled in the water near the stern because we've left the main
sheeted out engages as I sheet in.

Regarding The Scorpion, I'm familiar with this boat, we were a big
Scorpion Club back 'in the day' and I was only discussing a variable mast
rake device with Simon Dodds (our resident Hot Shot Laser & MPS rider)
Dad Barry, there's not much he doesn't know about scorpions and a
veritable mine of excellent intel. The boat he had was very much the
conventional kicker, but as I said he has the mast rake adjuster which is
linked with all this.

Rake the mast back and the kicker/gnav becomes even more important
(and has less room to manouvre) In fact there appears to be a logic that
suggests with a raked mast the gnav system becomes more relevant but
with the mast vertical the conventional kicker would appear to be more
suited to what's required. Given the more vert the mast, the less bend I
would want in the lower regions of the mast and vice versa.

We so need a sliding mast track to make all this perfect, not much chance
of that in our boat.


Posted By: Iain C
Date Posted: 12 Sep 08 at 11:39am

Thanks for the compliments GRF, I will pass them on.  But I agree, it's a lovely suit of sails, they are Fyfes imported from New Zealand, and the spars are C-Tech, a different company, but next door, and they work closely together.  Stuberry should be able to tell you more as he's met the guys in NZ.  That kite is a number 2, and measures in at about 42sqm.  Now the bad news...although that boat is usually sailed in 12 foot skiff configuration, it was actually built in '97 as a Cherub...shock horror...you've just complimented something Cheruby!!!  In fact, with it's little '97 rules Cherub rig, that is BY FAR the fastest I have ever been in a boat.  I have sailed quite a lot of fairly exciting machinery over the years, all the RSs, MPS, 12s and 18s but that's the only time I have been truly, genuinely scared in a dinghy (OK the avatar pic was mildly concerning too...)  Blowing a solid 6, no GPS but I would say we were well north of 25 knots.

Jim...temple vang and stump indeed...seems OK so far, however that stump is really, really beefy, much bigger diameter than the mast.  I am going for a similar configuration on my new boat, although after speaking to C-Tech and ordering the tube from NZ, they reckon I can probably get away with a much smaller one.  Still tempted to put a couple of layers of extra carbon on there for good measure though!

 

 



-------------
RS700 GBR922 "Wirespeed"
Fireball GBR14474 "Eleven Parsecs"
Enterprise GBR21970
Bavaria 32 GBR4755L "Adastra"


Posted By: JimC
Date Posted: 12 Sep 08 at 12:02pm
Originally posted by Iain C

they reckon I can probably get away with a much smaller one.  Still tempted to put a couple of layers of extra carbon on there for good measure though!

The stump on my Canoe is ridiculously over built too. The prospect of a failure is too much to contemplate! Its bad enough that I spotted a crack in the kicker anchorage on Sunday. It seems to be cosmetic but... I really don't know how I could repair it without taking half the boat to bits if it does go...


Posted By: Chris Turner
Date Posted: 12 Sep 08 at 12:20pm

Re Scorpion; we first put this on in '89, because the Scorp is not allowed any Lowers we used the lower boom set up to try not to induce so much mast bend when applying the kicker. Works well, does not add much weight and does have some mechanical advantages although gooseneck loads went up.

Gnav, I think it first went on the 4000, not sure if anyone else had done it before then, I then did a variation on the theme for the 14 (whilst working for Phil Morrison) for the 97 Worlds as I had just had knee surgery, with several incarnations it is now pretty standard.

This year we joined the fashion and put the temple vang system on, as I am now helming I wasn't too woried about it being in the way, however, we have had some issues with it and are now going back to the Gnav.



Posted By: G.R.F.
Date Posted: 12 Sep 08 at 12:32pm
Going off topic JimC and formerly 'publicly' apologising for having a 'pop'
at what I imagine is your SA ID, I am sorry, I was a bit scratchy
following the debacle here, but, I'm surprised you haven't also pointed
this out to us..

One of your fellow 'Canoe' ists wreaked savage revenge for taking the
"Canoe" name in vein. They don't hang about do they?

IOS Round the Island Race 2008
Date: Sat 30 August
Weather: SE/ENE F4-5, HW 13.00
Entries: 124
Fastest elapsed: 2:10:30 (Tornado Sport) - new course record.
Slowest elapsed: 6:50:44 (Bosun)

Overall Dinghy & Cat Results on PY
Pos     Helm/Crew      Class     Sail No     Club      Rating     Start  & nbsp;  Finish     Elapsed      Corrected
1     Aaron Young/Rob Butterfield     Tornado Sport     7      Datchet Water     650   &nbs p; 11:30:00     13:40:30      02:10:30    &nbs p;03:20:46
2     Rob Lawes/Stuart France     Formula 18     740    & nbsp;Whitstable     691      11:30:00     13:5 2:46     02:22:46      03:26:37
3     Huw Reynolds/David Williams     Formula 18     3    &nb sp;Whitsable     691  &nb sp;  11:30:00     13:56:0 8     02:26:08   &nb sp; 03:31:29
4     Dan Norman/Scott Atkinson     Hobie Tiger     1979   &nb sp; IOSSC     689  & nbsp;  11:30:00     13:58 :05     02:28:05   & nbsp; 03:34:56
5     Mark Goodchild     Int. Canoe (Standard)     265    ;  Wilsonian     905  ;    11:00:00    &nb sp;14:15:25     03:15:25   ;   03:35:56
6     D Figgis/R Lamb     Tornado Sport     407   &nbs p; Whitstable     650 &nb sp;   11:30:00     1 3:53:39     02:23:39  &nb sp;  03:41:00

I am suitably chastised and bow to the superiority of the 'class'.

Whoever that guy is I'm impressed, not the easiest of conditions and it
simply can't be an 'easy' sail.



Posted By: JimC
Date Posted: 12 Sep 08 at 12:50pm
Originally posted by G.R.F.

5     Mark Goodchild     Int. Canoe (Standard)

Whoever that guy is I'm impressed, not the easiest of conditions and it simply can't be an 'easy' sail.

Mark has won one Worlds, two European and a number of UK National Canoe Championships. I'm happy if I can finish on the same lap as him...


Posted By: dics
Date Posted: 12 Sep 08 at 1:24pm

Originally posted by JimC

Originally posted by G.R.F.

5     Mark Goodchild     Int. Canoe (Standard)

Whoever that guy is I'm impressed, not the easiest of conditions and it simply can't be an 'easy' sail.

Mark has won one Worlds, two European and a number of UK National Canoe Championships. I'm happy if I can finish on the same lap as him...

I used to sail with his Dad. He's pretty handy to!



Posted By: craiggo
Date Posted: 12 Sep 08 at 1:41pm
Chris,

Thanks for providing your info on the Scorp arrangement. I first saw it I think back when I sailed at Elton SC. during my uni days but have only come into contact with newish Scorps only 1 since then (The Speed Sails works boat from a couple of years ago) and it has a conventional kicker.

Anyway now I know my memory still works, I'll leave it at that.

Paul


Posted By: Ross
Date Posted: 12 Sep 08 at 4:42pm
Gnavs just seem a bit rubish to me. If I was building a boat then a Temple vang or a 'dog leg' is what I would go for.

-------------
Ross
If you can't carry it, don't sail it!


Posted By: Lukepiewalker
Date Posted: 12 Sep 08 at 7:37pm
They have always seemed somewhat like an answer to a question nobody asked to me. Finns only really have two controls you won't find on a laser, the inhaul and the centreboard pennant (admittedly the traveller control is a lot more sophsticated). It's just they are all handily lead to the same place. I think the kicker (which allegedly has it's origins in model yacht racing from way back when) was secondary to the traveller when small blocks and ropes weren't as good as they are now, so the traveller was the way to do it. This has now been superseded by all those lovely modern systems with strong light blocks and nice ropes, leaving us with the traveller based boats being the ones with a long history which has left them with low booms (Finn, Europe) and other boats where you can see where the traveller used to be (420's, Solos) but it has since been replaced with a bridle or a shorter traveller.
I digress, and have started rambling... Carry on...


-------------
Ex-Finn GBR533 "Pie Hard"
Ex-National 12 3253 "Seawitch"
Ex-National 12 2961 "Curved Air"
Ex-Mirror 59096 "Voodoo Chile"


Posted By: Iain C
Date Posted: 13 Sep 08 at 12:16am
I'd heard kickers were invented way back when in the early days of bermudan sloop racing...some chap had a wire one that he'd put on before the start and then take off at the end, no-one really saw it and everyone was wondering why he always served them up some whuupass....

-------------
RS700 GBR922 "Wirespeed"
Fireball GBR14474 "Eleven Parsecs"
Enterprise GBR21970
Bavaria 32 GBR4755L "Adastra"


Posted By: alstorer
Date Posted: 13 Sep 08 at 12:24pm
Originally posted by Iain C

I'd heard kickers were invented way back when in the early days of bermudan sloop racing...some chap had a wire one that he'd put on before the start and then take off at the end, no-one really saw it and everyone was wondering why he always served them up some whuupass....

You're thinking of Paul Elvstrøm, still officially the best Olympic Sailor ever- four golds beats three golds and a silver. He did indeed have a fully removable one to keep the invention secret.
---
off topic bit

He's also credited with inventing Toe Straps, the kick-down self bailer, and the Leeward Gate (instead of a single leeward mark).

off topic bit
---


Posted By: Chris 249
Date Posted: 13 Sep 08 at 12:40pm
The Int 14s had vangs before Elvstrom got into sailing. They picked them up
from model yachts. This comes from my 70 year old copies of Uffa's books.

There were some people who used to sneak around with them; just like they
used to paint light wooden centreboards to look like heavy bronze ones and
would then carry them, with 'great difficulty', through the rigging park.

Hiking battens and (I think) hiking straps were used before Elvstrom, but he
took it to a new level.




Posted By: Lukepiewalker
Date Posted: 13 Sep 08 at 1:22pm
Yes, I did notice his Wikipedia entry credited him with a few more innovations than he had claim to. Although that shouldn't detract from the ones he does have claim to.



-------------
Ex-Finn GBR533 "Pie Hard"
Ex-National 12 3253 "Seawitch"
Ex-National 12 2961 "Curved Air"
Ex-Mirror 59096 "Voodoo Chile"


Posted By: redback
Date Posted: 14 Sep 08 at 10:30am
Gnav - fantastic idea. Powerful, reliable and gives the
crew more space. They also mean the lowers are attached
higher increasing access to the foredeck.

As for mast bend that is easily controlled by the lowers
so you can have as much or as little as you like. The
system on the 4000 also takes a lot of forces off the
gooseneck. The only time mine has ever broken is when
the crew jumped on it from the racks when the boat was
on its side. I'm a convert.



Print Page | Close Window

Bulletin Board Software by Web Wiz Forums® version 9.665y - http://www.webwizforums.com
Copyright ©2001-2010 Web Wiz - http://www.webwizguide.com