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-   -   Rig tuning/ rounding up (http://www.star-board-windsurfing.com/forum/showthread.php?t=4020)

tjanulis 11th June 2008 06:47 AM

Rig tuning/ rounding up
 
Lately I have been having the problem that I round upwind in all but extremely low wind. I am sailing a 145 Carve with the fin it came with, a 520 Drake. I often sail with either a 6.5 Gaastra GTR (no cams) or an 8.7 Gaastra Nitro 2 (4 cams) on a 490 29 imcs mast. I have tried to follow the recommended settings as a starting point. I have been sailing in more aggresive conditions than in the past, and I am guessing that this problem never showed up because I was never pushing as much before or I am doing something wrong.
As soon as the the wind hits around 10+ knots the board wants to round up. Even when I try to uphaul, the board wants to spin right into the wind and stall. I have been successful at putting my front foot really far forward (in front of the mast base)to get the board going, and once on a plane I have to keep my front foot right by the mast base to keep the board from rounding up into the wind. I believe that it is a rigging/tuning error, because recently while in Fla. I rented a board from Calema, and had no problems, just great sailing. I also had someone else try my setup and they were feeling the same things that I felt. I tried moving the mast base from the center of the track forward, and then all the way back, but it didn't seem to eliminate the problem.
Last weekend I decide to try varying the outhaul and the downhaul to see what happened. I kept the mast base in the center of the track. I tried adding more outhaul to try and move the center of effort forward. It may have helped but not enough to stop the problem. Then I tried releasing downhaul tension a little. Again, minor change, still the tendency do roundup. Then I released the downhaul tension until the leech was tight, still not enough to eliminate the problem.

Any suggestions or comments would be much appreciated.

marek 11th June 2008 07:58 AM

Can't really answer here but would love to hear some advice as I'm having exactly the same problem.

My background: Starboard F-type 148 in any wind - no problem with rounding up at all.
Any other smaller board = problems. Last weekend I rented Goya FSR 125 which is a modern design and has very similar dimensions to Carve 111 and when the wind picked up I was rounding up constantly, very depressing :mad:.
Tried the other 2 smaller boards in the past in strong winds - the same problem. (one time I couldn't even start - the board would go sideways).

I know from theory that I should put more pressure on the mast foot over my harness lines/boom and I was thinking I'm doing it, but perhaps not enough.
I'm also moving my sail forward and windward a lot but it doesn't seem to solve the problem.

It's confusing, because I'm keeping quite a good balance on a smaller board but still I'm getting so much tired from making it going downwind all the time. How come it doesn't happen to me on a larger/wider board?

Please help!

-marek

Roger 11th June 2008 11:44 AM

Hi guys,
Hmmmmm..... interesting experiences both of you are having here.
First, let's define the things that can cause your board to round up.
#1...... the rail to rail (roll axis) trim of the board is upwind rail lower than downwind rail.
Why..... because your stance is putting your weight/center or gravity upwind of the boards centerline, or you are putting weight on your front foot which is upwind of the centerline, without compensating by putting your back foot "heel on centerline" to compensate for the added weight upwind of centerline and bring the board back to level (rail to rail).
#2....... Raking the rig back too soon.
When you are starting to get underway (either a short board or a longboard here) you need to ensure that the rig is fully perpendicular (the axis or line drawn from center of the mast to the center of the boom end) to the fore and aft axis of the board.
If you do not get the rig perpendicular, but rather start to sheet it in before you really got the board and rig "aligned" in the "T" position, the board will instantly try to turn upwind. It's doing exactly what you are telling it to do if you rake the rig back as you sheet in the sail to power it up.
#3...... Mast base is positioned too far back on the board (but this is easily compensated for by keeping your rig a bit more forward (tipped forward over the universal joint to put more of the drive from the sail further forward when getting underway.
For sure, Marek, you need more time on the water to discover how much more sensitive a narrow board is than you F-Type 148.
The F-Type 148 is very forgiving about rail to rail mis-trim (mistrim being other than perfectly flat rail to tail). Smaller and narrower boards are not.
For tjanulis..... What was the board you rode at Calema and how does the width compare to your Carve 145.
I suspect that both of you are not getting your board/rig fully perpendicular to the true wind when starting to get underway, and then to compound the problem you are not keeping the rig forward long enough to get the board fully moving before you add a bit of weight upwind of the centerline.
Keeping the rig upright (fore and aft here) or perhaps a little tipped forward or upwind a bit is not difficult, but I'd guess in your haste to get things going, you have passed over or skipped this very important skill.
So, try this.... work on getting the end of the boom straight downwind, and the rig balanced with the board fully in the "T" position right across the wind.
When you sheet in to start out, if the board starts to turn upwind, tip the rig a little more forward.
Be very careful with your footwork that you truly keep the board "flat" rail to rail.
Thie will help the board to plane off earlier.
As you move back progressively on the board, with your feet, try to keep the rig more forward to keep the board from turning upwind.
Do not try to "rake the rig back" until you are pretty much fully on a plane.
Once the board planes off, and you are in the footstraps and hooked in, THEN worry about raking the rig back.
I don't think either of you really have a rigging problem, or a mast foot positioning problem, but you've learned to leave out some very important "alignment" issues when getting underway.
Tjanulis...... where do you live.... anywhere near Cape Hatteras..... I'd love to see how you are rigging your sail and what your technique is.
You've really piqued my curiosity.
Hope this helps,

marek 11th June 2008 12:15 PM

Thanks Roger, I'll try it next time.
You're right that F-type is way more forgiving than any other smaller shortboard I've tried.

Also, I've just recalled, I actually had a similar problem even on my F-type - at the very, very beginning I couldn't get it moving, it would round up on me.
Later on my friend who was learning had the very same issue.
What helped me then was to (1) get the sail perpendicular like you said, but also (2) tip the mast windward until I could see the nose of my board over the window in my sail and THEN start sheeting in.
The 2nd one I actually got from a windsurfing book and it really helped me, I guess I forgot about it and have to use it (more extensively) on a smaller board.
Whatya think?

-marek

P.S. If you have a chance, will you take a look into my "back footstrap problem" post?

Ken 13th June 2008 12:27 AM

What Roger said...........

In simple terms from my view -

Where I sail, and in most places, the wind and waves aren't at 90 degrees to one another. This makes you think you have the board perpendicular to the wind, but you don't, it is actually pointing into the wind or bearing off. You probably find that your heading up problem is generally occurs when you are on starboard or port, but not both. Sheeting in the sail to gain power will instantly head you up into the wind.

Usually when sheeting in, you will add weight to the back foot, which just makes the problem worse.

If you begin the whole thing by being sure that the board is heading 100 - 110 degrees off the wind, it should go fine.

tjanulis 13th June 2008 03:04 AM

Roger,
The board that I rented at Calema was a 160L Fanatic, I think the one that I rented was 80 or 82cm wide, my 145 Carve is 78cm wide a difference of 2 to 4cm. Is that enough of a difference to mask a technique problem?
I guess that I am focusing on the rig and tuning because I had a good session on rental gear, and I had someone else try my rig and give me the same feedback on what I was feeling. That is not to say that I am ruling out my technique, actually I would love to find out that it was something that I am doing wrong, I would just like to figure it out!
I even weighed the board to see if it was the same weight as the mfg specification, it was.
I live in Northern NJ, sorry not really convenient to Hatteras.
If I get out this weekend, I am going to make a conscious effort to make sure the rig is perpendicular to the wind before starting, keeping the board flat, and keeping the sail upwind a bit more.
Could you clarify what you mean when you say “get the board fully moving”

Thanks

Roger 13th June 2008 09:44 AM

Hi tjanulis.
If you don't solve the problem this weekend, what are you doing next weekend.
It just so happens I will be in Atlantic city, NJ next Sat and Sun.
If you could come by this event for a day, I'd love to sail your board and rig to see
what might be causing your issues.
Also, we can really tune up your rig to make sure that is not some part of the problem.
Hope to see you at Lakes Bay.
R

Ken 13th June 2008 08:42 PM

Here is a supplemental thought after getting out yesterday on my iS 111.

Big sail on a short board = heading up in sub-planing conditions.

I was on a Maui Sails TR4 7.6. This sail on the short 234cm board causes me to put a fair amount of pressure on my back foot whenever I sheet in because of the relatively long boom, which extends well beyond the tail of the board. If I am slogging waiting for a puff of wind and sheet in too soon without heading off the wind, the board rounds up very quickly.

In sub planing conditions, even if I am on a beam reach, the board always wants to head up. I can't slogg comfortably while hooked in waiting for the wind without continually forcing the nose of the board back to a beam reach (front foot pressure and moving the sail forward). Once on plane, no problem heading up, the board goes where I want it to go.

I don't know if this observation applies to your situation, but for what it's worth.......

Ken

tjanulis 13th June 2008 09:24 PM

Roger,
I will be at Lakes Bay Sunday (6/22), I had planned on it because I had seen that it was a demo day. It will be nice to meet in person.
Ken,
I think what you observed does apply to what I am experiencing. Roger also mentioned that in my haste I am not fully letting the board get going before I try to sheet in.
Thanks for the thoughts and help

Ted

tjanulis 18th July 2008 04:21 AM

Thank You
 
Roger,
Thanks for your help. The four words that made the difference for me were, "move the mast upwind". That has cured the rounding up problems that I was having. I guess that I was sheeting in, but not keeping the ceter of effort of the sail over the right spot of the board.
The reasopn that it has taken so long for me to get back on this was because the I haven't been out in conditions that let me try this out.

Thanks again.
Ted


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