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49er Newbie Questions

Printed From: Yachts and Yachting Online
Category: Dinghy classes
Forum Name: Technique
Forum Discription: 'How to' section for dinghy questions and answers
Printed Date: 22 Sep 20 at 5:29pm
Software Version: Web Wiz Forums 9.665y -

Topic: 49er Newbie Questions
Posted By: LiquidIce
Subject: 49er Newbie Questions
Date Posted: 27 Sep 11 at 9:50am
Hi guys, I am a relatively new 49er sailor and it seems like there are some good 49er sailors on this forum so what better place to ask some silly questions! :)

Bit of background, I have a 6 year old 49er in australia with an old rig, which i steer and have sailed 10-15 times so far. We are starting to get out of 'somebody get me off this death trap' mode into looking for speed and height

Lets start with the rig:
3 sets of shrouds... WOW... 
I understand the basics (or think I do), Caps on in light winds to keep the mast up, caps off in heavy stuff to let some power off. Not so sure what to do with the lowers and the shrouds.

What effect does shroud tension have on the rig? Should it be incresed or decreased as the wind increses.

With the shrouds and caps obviously being on one turnbuckle, does this mean they are adjusted together all the time? If i was on the water and the wind went from 10 to 20 knots would i be winding the turnbuckle down or easing it off?

Lets talk sails:

Is Cunningham a last resort depowering tool or should it be used alongside the vang in medium conditions? (15 knots)

I read an article which suggest the height of the jib hoist should be adjusted for the wind, is this something people do?

How much jib sheet do people dump for tacks? I have been dumping around half a foot but not sure it is enough.

Thanks in advance,

Posted By: Iain C
Date Posted: 27 Sep 11 at 8:43pm
Been in a similar position myself (still am!)
Have a look at the shock sailing website for some great tips.

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

Posted By: LiquidIce
Date Posted: 28 Sep 11 at 11:47pm

I have read all the shock sailing stuff, and is has been very helpful, I was hoping for some clarification on what effect the various settings actually have on the shape of the mast.

The shock sailing guide says that you should tighten the shrouds and caps in equal proportions as the wind gets stronger, this makes sense, and explains the turnbuckle, but goes against what the other 49ers in my area have told me, which is that as the wind increases you loosen ONLY the caps so that the top of the mast is allowed to lay off.
What effect does tightening them both together have on the shape of the mast? does it allow the top of the mast to lay off?


Posted By: 17mika
Date Posted: 02 Oct 11 at 11:55pm
Hi, first I'm not at all a 49er guru, so a more informed answer would be veery welcome.

On my 29er XX (which is an exact small size reproduction of the new 49er rig) I am buying the idea that in most conditionsyou just play with the top turnbuckle (and with lowers). when it's windy you get more tension distributed in the whole mast, which flattens the whole sail (in strong winds you need the whole sail to flatten, to reduce both power and drag of the main)
After all the upper leech to open a bit doesn't really need  the upper mast to bend to leeward; if the upper mast bends just aft in the gusts (and not sideways, since a tightened top shroud avoids that), the upper main flattens and the leach still opens a bit (because the line from top to base of the mast shortens and the sail naturally twists a bit).

IMHO (I repeat IMHO) in most conditions that's enough; you want the uppermast to be really free  (i.e. loose caps) only if it's veeeery gusty, to get an even greater gust response. In all other conditions if tops are too loose i'd say that you lose too much pointing ability upwind because the top of the main twists too much.

But that's just my not too much informed view :)

Posted By: LiquidIce
Date Posted: 09 Oct 11 at 12:16am
Thanks, that explains the shrouds issue very well!

Would I be correct in saying that the relative positions of the shroud and cap pins on the chain plate are of paramount importance?

I will have a play with using the turnbuckles!


Posted By: Skiffman
Date Posted: 09 Oct 11 at 9:39am
Basically you should normally leave the caps in the same pin hole on the chainplates. Set up as per the shock guide with about 7mm bend, 28 on the shrouds and 14/15 on the caps. The tension numbers are with a standard loos gauge with plastic rollers (not metal), but for anyone with a loos gauge be careful you do not wear the rollers down as they change what the gauge will read. For example as the rollers wear down gauge will read less, so when the gauge use to read 28 now it will read 26. Can catch you out if your not careful. 

So once you have set up on those numbers just wind down the main turnbuckles as the wind increases. The maximum turns we use to go on the old rig was about 20 turns which should get the shrouds to about 36. 

Downhaul on the old rig is very effective at flattening the main, so much so that we would only use it when it got really breezy. The kicker swell really flattens the main as well as closing the leach compared to the new rig, so you have to be careful about when to use the vang.

The jib tack, basically start about 10mm above the swage in the light down to 20mm under in 20 knots. We never ease the jib sheet unless its very windy and we are struggling to bear away. 

Finally the 29er XX is not the same as the new 49er carbon rig, the XX rig is still glass fibre rig like the old 49er top section. 

Anyway have fun, theres a bunch of 49er guys down that way that will have a lot of advice to give

49er GBR5 -
Team Fletcher and Sign campaign site

Posted By: Menace
Date Posted: 10 Oct 11 at 9:54pm
Forestay gauge point (30-32) Turnbuckle number Shrouds tension Shrouds pin numbers Caps tension Cap pin numbers Lower bend from front of mast Lowers Turnbuckle Number
Heavy (18 knots+) 3.5 35-36  7 front 10-12 4.5 back 30mm 3.5
Medium(15-18 knots) 3 33-35 7 front 13-14 4.5 back 30mm 3.5
Medium (12-14 knots) 2.5 32 7 front 14-15 3.5 back 28mm 3
Light/Medium (8-10 knots) 2 28-30 7 front 15-16 3.5 back 8-18mm 3
Light (4-8knots) 1.5 27-30 7 front 16-17 3.5 back 8-18mm 3
Dylan's advice is spot on, here's our old boat's settings if it's any more help on top of the advice given. Seemed quick and we were 140-150kg when sailing off these. Happy flying....

Posted By: 17mika
Date Posted: 11 Oct 11 at 7:22pm
Originally posted by Skiffman

Finally the 29er XX is not the same as the new 49er carbon rig, the XX rig is still glass fibre rig like the old 49er top section. 
Are you really sure? My xx mast (from 2009) seems all carbon (the spreaders only are glass fibre, and the top of the mainsail track is grass fibre as wall), I've always heard the tube it's 100% carbon
I've seen also 2007 xx masts (which seem almost equal to mine) and 2010 masts (which have plastic mast track, glass fibre shrouds and some carbon reinforcements in some points on the tube).
I also find it hard to believe it can be glass fibre, since it's veeeeery thin and pretty light.
PS sorry for the the thread hijack, and thanks everybody for the useful setup info
PPS when people talk about bend measurement (8mm, 30mm, etc..), what is measured?

Posted By: LiquidIce
Date Posted: 12 Oct 11 at 10:21am
Thanks skiffman! Those are very helpful tips. So on the old rig the crew should have his hands pulling on the mainsheet before the vang gets touched much?

With the Jib tack... what effect does raising it as the wind increases have? Is the intention to close the slot?

Cheers menace for the settings! It is always hard to find stuff for the old rig, I will print that out and see how that goes next time I sail!

Is the tuning of the new rig incredibly different to the old? We are hopefully upgrading shortly... How much will have to be re learnt?


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