Your expert opinions wanted on some tuning issue on my boat.

Talking about a Taipan F16 with a medium size squaretop F16 mainsail. The main is cut to be a part of a 2-up sloop rig with about 140 kg as a crew. I'm using the same mainsail for singlehanded racing. The main seems to work fine on the downwind legs and reaching legs. No F18 can easily overtake me and often I run at the same speed or faster.

My issue is to be found on the upwind leg. I feel that there should be more in it on this course. Current situation is :

-1- when sailing 1-up I seem to be able to match speed and pointing ability of the leading F18's on the upwind course, I can just pinch a little higher then them but the boat slows down really quickly if I overdo it.

-2- When sailing 2-up I seem to be able to achieve the same or slightly less VMG on the upwind leg when I steer just a couple degrees lower than the lead F18's and lets the boat run freely. I always put this down to a inherent characteristic of the Taipan design; most comments seem to suggest that I likes to run a little lower and achieve good VMG through speed. However the point that gets me is the fact that when singlehanding without the jib I do not seems to point much higher, only about 5 degrees or so.

What do you resident experts think ?

Is this the result of using a main optimized for 2-up sloop rigged sailing and something that can only be solved by getting an optimized main for 1-up sailing ?

Can I somehow alter my rig settings (prebend / spreader rake etc) to improve on this ?

Did Taipan 4.9's show a similar behaviour when singlehanding ?

Other suggestions ?

Right now it all feels to me like I open up my leech to much when I downhaul the sail to get a boat that doesn't lift too much and as a result I loose pointing ability. If I loosen the downhaul I feel more able to point high (not sure if I really do) but the boat is definately more flighty.

Maybe I'm missing the fuller bottom halve of the sail that uni-rig mainsails seem to have and which is cut out of sloop mains ?

Any suggestions are welcome.

Basically I'm doing alright again the F18's but I just want to be able to finish 50 mtr ahead of them instead of them overtaking me 50 mtr before the (upwind) finish. I don't need much extra pointing, just enough to be able to outpoint them by a few degrees without loosing much speed.

Wouter

For 2 up pointing and speed, make sure you have a good jib (we have just re-learnt this with our new jib, and I tought I would mention it even if I am no expert! You mentioned earlier that you had re-cut your jib luff, so..).

Hi Wouter, I'm definitely no expert here, but I do have a T4.9 and here are some of my opinions to your questions.

1. Yes, I do think there are benefits of getting a main cut for 1 up sailing. I have always wanted one of these. While I don't think the difference will be mind blowing, I am guessing a one up main would be much flatter and make the boat less powered up so early. As a result you would likely need less downhaul and you'd have more leech tension. However, along with the new main, I am guessing you would need to change your mast setting as well.

2. I think changing the mast setting may make some difference, however, I think a main cut specifically for 1 up would probably have more effect. There is a reason why the 1 up guys in oz have completely different sails and masts for 1 up configurations.

3. I singlehand my T4.9 most of the time using a main cut for the sloop rig, and yes, in cat rig, the boat does not like being pinched at all. I get much better VMG just footing off and going for speed and power. I personally think one of the reasons for this is that the volume of the hulls are made for 2 up, so when singlehanding and pinching plus trying to punch through chop, the weight of 1 person is not enough to force the bow through the waves. The bow rises over the wave, gets blown to leeward and you lose a couple of feet on the crest of every wave. Of course if you're a 100kg guy, maybe this might not be an issue for you, but for a 75 kg guy like me, it is.

4. Solutions? Have you thought just pulling the rotation towards the centre a tad more? This might settle the boat with a little less downhaul. I also tend to sail the T4.9 cat rigged with the traveller off the centre line by about 1-2 inches and while i lose some pointing, the speed is much better. The boat is more settled and you don't need to hal in as much downhaul, solving the problem of inadequate leech tension. The speed then allows the boat to just "lift" to windward even though my bow isn't pointed that high.

Hope this helps

Here are the results of the last 5 races that I did solo on the F16 1-up.

I raced the boat with the same settings as when I sail 2-up sloop rigged, so I didn't change any prebend, spreader rake or mast rake etc.

I'm also writing this post to say that I'm putting my results were my mouth is.

From the beginning I though, said and claimed that a 1-up F16 can, will and must race of the F18 rating. Here in the Netherlands I have equately the same rating as the F18 when sailing the F16 in either configuration. If I were to have the same 1-up rating as the US sailors than I would race of 109 instead to 102.

You can look up the results here :

http://www.wvz.vuurwerk.nl/uitslagen05.html

with the 5 last races (all solo) here http://www.wvz.vuurwerk.nl/kc180905.html and here http://www.wvz.vuurwerk.nl/180905.html

Race 1 (kennemer cup) I finished 7th/20 (although 22 boats are listed as having started)

Here 2 I-20's and 3 F18's finished ahead of me with the 2 of the F18's finishing just in front of me. I made a mediocre approach to the last gate and rounded it is similar fashion and I had to give way to both F18's who then finished in front of me. I left 5 F18's and 1 I-20 behind me. All on elasped time of course !

Race 2 (kennemer cup) I finished 8th/18

This race like I had more speed on the water but also that I had more boats in front of me, a strange experience. Especially considering that I did pretty much the same in the end result. 2 I-20's and 4 F18's in front of me and 1 I-20 and 4 F18's behind me. Again all on elapsed time, thus racing first over the line wins.


Race 3 (last day of the club race series) : I finished 8th/14

This result should have been alot better ! Because of the 4 F18's that were in front of me at the finish; the last 3 were only by a minute or less. I actually had them behind me at the last rounding of the C-mark but I just couldn't keep them behind me on the last upwind leg to the finish. All 3 of them overtook me when I had to make a tack for the finish line. Nevertheless 2 out of 3 I-20 were behind me and so to 2 more F18's


Race 4 (last day of the club race series) : I finished 5th/11 (with 14 boats entered)

In this race I made the biggest mistake of the day. In the first race we had left all marks to starboard, however the RC changed this to leaving all marks to port for the second race. I had a very good start and was in 2nd place behind the modified A-cat and I was to the luff of all other boats giving them bad air. So I saw everybody tack away. So I'm thinking this is going really well I can actually make the A-mark in one stretch. Wait a minute ! The course can never be thus biased. Darn I and 3 others are going for the wrong mark ! Everybody else has tacked to get to the right mark. So right before reaching what I thought was the A-mark (but actually was the B-mark) I tacked and reached towards the correct A-mark. Still rounded her in 5th or 6th place. So the damage was limited but still I lay 2nd before making this mistake. After finishing I had 1 I-20 and 2 F18's in front, with the F18's only at 32 and 20 seconds in front of me. I also had 2 I-20's and 2 F18's behind me. All on elasped time.



Race 5 (last day of the club race series) : I finished 4th/6 (Quite a few called it a day after the 2nd race, the hardcore sailors stayed of course ! )


This was my best race I lay 2nd for the most of the whole race. With only 1 I-20 in front of me. Our local sailing God called Hans Klok sat motionless on the startline as his mainsheet came undone and he had to refit it after the start of the race. However Hans sailed a great race and finished in 2nd place non-the-less. I tried my best to defend my 3rd spot and tacked below the lead F18 on the layline to the finish in the hope of staying in front of him but it was no use. The Hobie Tiger literally snatch the 3rd place from me in the last 50 meters before the finish line. I finished 11 seconds later. Still leaving the other F18 behind me.



While being thoroughly satisfied with the nice weather we had for our last race day I was a little down-spirited to each time have lost my places in the last meters to the finish. However when looking at the results I feel that the performance of me on the F16 is were I claimed it would be. A few better tacks here and there and I will have won those 30 seconds back that I need on the finishline.

Mind you the sea was choppy and waves were hitting our all our main beams from time to time. Make a mistake and you would be brought to a standstil by one of these waves. Winds were about 10 knots with later in the day gusts to about 14 knots. I had to dump my spi a few times to survive of potential capsize. I was thoroughly beat after 3 such races. You had to work the mainsheet nearly all the time upwind and work the spi continiously downwind and I have a desk job during the week !

If I had been racing of the US PN rating numbers then I would have scored a 3rd, 2nd and a 3rd place on handicap in this fleet. Behind Hans Klok on his modified A-cat called an open 15 square with angled boards and our reigning club champions for 3 years in a row on the I-20. I would have been ahead of all others and all F18's and seriously, I'm really not that good as a sailor.

So there you have it. Race F16 in both 1-up and 2-up modes of the F18 handicap.

Wouter

Eric and Jennifer ? Both of you have a sloop main and a main cut specifically for singlehanded use, right ?

What are your experiences with these two mains ? (when using both for singlehanding)

Wouter

Yep that is what I'm finding as well. Basically; my VMG is not to bad at all, it is just that it feels like it should be able to point a little higher.



That is a good idea. will try that next time. Indeed then one can leave the downhaul less tight hopefully bringing back in the mid section of the leech. All the other stuff I tried already.

I have a good mind of e-mail a guy like Glenn Ashby with these questions as well. We've been giving him a good share of the F16 sail sales so ...

Wouter

Wouter

I will try to help, although I have not used the AHPC mast so I can give you no settings.

Still the same rules apply to all rigs, basically you are trying to achieve the most powerfull sail that you can hold on to and still keep lots of mainsheet tension without falling over or having to pinch and go slow.

It is usually about how you de-power the sail that makes the difference in speed. This is achieved by bending the mast. It sounds to me as though you have too much power when sailing 1 up, so when you sheet hard and point up the high drag sail goes slowly so to keep speed up you are sailing lower with a loose-ish mainsheet, which is also high drag.

The standard way is to downhaul the sail untill you can go no further, then pull the mast rotation in. the problem with this system is that although as you pull the mast in it cause the lower 2/3rds to bend more, it stiffens up the top 1/3, so some stiffer battens may be required.

Another way, is to leave the mast rotation as it is (about 75 degrees, then when you get above max downhaul conditions loosen off the diamonds by 2 full turns so that when sailing the windward diamond is loose, this has several benefits, the top section is still in the bendy mode, the lower section is allowed to bend for and aft to take up the slack in the spreaders, so flattening the sail, and the mast still remains at the optimum angle of attack for the leading edge of the wing. I think this may work particularly well on your rig as it has a more pointy front, (the rounder fronted masts are more forgiving to angle of attack. When doing two boat tuning on Stealths sailed single handed we found that loose diamonds, truck loads of downhaul and a very very stiff 3rd batten were very quick in above 12 knots, we also dropped the traveller by a couple of inches, going as far as 40 cm in very strong winds.

Some more info on the speeds in different wind conditions would help.

regards

john

wouter,

I remember you once stated how few spreader rake you uses. if you don't change it for single handed you definitely will end up in those problems you describe!

I don't agree in the believe diamond tension can save you.
first comes spreader rake, than comes diamond tension.

remember I once put landenbergers sailings tip here into this forum. just read it! if you miss something read it twice... but than try more prebend! you will discover a complete new world!

best might be to change by 30-40 mm to feel really the difference. than you go back to shore and decide if you test again with 15 mm even more or it already was to much and you choose for less... its important to do this changes quickly after each other to sail in the same wave and wind conditions, otherwise you cannot judge it! of course diamond tension should be kept constant. changing diamond tension is fine tuning, spreader rake tunes the essentials!

have fun!

Dirk,

Thank you for your reply. Indeed I'm converging strongly on doing something with the spreader rake.
I think I will stay close to the current settings when I go out as 2-up sloop, maybe increase rake just a little to get a little bit better accelleration in gusts. But for 1-up catrigged sailing I think I will really increase spreader rake while keeping the same diamond tension. Thus try to get the pumping action going in the gusts and get accellerations instead of lifting and thus hold back a little more on the downhaul tension. Should make the sail flatter (especially in gusts) and still make the leech stand-up better (less downhaul)



I'm throroughly abandonning this "story" too. I don't believe as well.

Actually I'm converging more and more to the believe that diamond wire tension is a non-issue. If both spreader rake (pumping in gusts) and prebend (settign draft and leech tension) are things you adjust first to their optimal level than diamond wire tension is a given as you don't have enough degrees of freedom to also adjust the wire tension for a given optimal combination of spreader rake and prebend.

I remember landenbergers sailing tips and yes, good idea, I will reread them.

Thanks for your post Dirk.

Wouter

Do you have a Landenberger spinnaker ? If not then what make is it.

And how do you feel about the spi ? Assuming that you have been able to find the optimal trim for it yet.

Wouter

Wouter,
I didn't follow what you meant by "pumping in gusts" in reference to spreader rake?
Jerry

It is a describtion that Greg Goodall used when I asked him about spreader rake. Apparently the angle of the spreaders determine how much the prebend chance during a gust. More rake and the prebend changes more and less rake then the prebend changes less. This seems to be linked to accelleration of the boat. If she doesn;t accellerate to much or not at all during gusts, but seems happy to lift then it is adviced to increase spreader rake. Or at least that is the advice for boat using the Superwing mast section.

Wouter

Wouter,
Thanks very much for that clarification - now it makes perfect sense!
Those are the kind of tuning tips that are so useful...
It is beginning to sound like it's more useful to tune spreader rake than diamond wire tension based on windspeed/crew weight (although maybe adjusting spreader rake will require readjusting diamond wire tension to get you back to where you started on the latter). Most boats have turnbuckles to adjust diamond wires before sailing and a few adventursome folks have added on the fly controls for that; so why is there not a way to adjust spreader rake without taking the mast down? A couple of very small hydraulic cylinders (and I'm sure there are other even simpler ways to skin that cat) and you could do it on the fly! I want one...
Jerry