Upwind without centerboard
Could you describe the upwind techniques used in non-planning conditions on boards without centerboards? I've tried going upwind with the centerboard raised on my current board, but it didn't work very well.
I'm currently using a Mistral NTrance (specs below) that has served me really well particularly in light and variable wind conditions which unfortunately is common around here. However, I can't help but want to get planning earlier and wonder if a board like the Go 155 would help with this? How does the Go 155 perform in non-planning conditions? Would I have trouble slogging upwind without a centerboard? I'm presently using the centerboard fairly regularly upwind.
Length: 280 cm
Width: 80 cm
Volume: 200 L
Fin: G-Sport Driver 60, Curtis CR-12 51
Sails: Retro 9.5, NP Solo 7.0
Sailor 6'1", 195 lbs
You can "experiment" with your NTrance quite easily to see how getting upwind
without the centerboard (CB) works.
If you were to get a new board (without a center board), at your weight I'd suggest a
slightly wider and more lightweight board than the GO 155.
Here's the technique:
Instead of keeping your board as "flat" rail to rail as possible (gets you planing the earliest) try stepping off center toward the windward rail slightly.
The idea is to tip or "cant" your board so the rocker in the bottom will take you upwind
due to it's shape.
You don't really need to "rail" your board all that much to get the water flowing under the "canted" bottom shape to steer your board upwind.
The largest difference is going to be rig positioning (steering).
Currently, to go upwind with the CB fully depoyed you rake the rig back (clew end of the boom down slightly) and your board steers upwind because you've moved the Center of Effort (CE) in your sail back toward the fin (relative to the Center of Lateral Resistance (CLR) created by the fully depolyed centerboard.
(I hope you either have it all the way up or all the way down (deployed) as partial deployment (say 45 deg.) really doesn't work and makes your board very hard to steer as the lift from the CB is not positioned correctly relative to the rig and the foil is very inefficient went set at 45 deg.)
So, if you raise your CB you lose the CLR of the CB. Now you only have the fin as your lateral resistance, and in sub planing (slog) mode the fin does not have enough water flowing by it to give you any real lateral resistance.
You need to "create" lateral resistance further forward under your board.
You do this by tipping the upwind rail down a bit so the board wants to "follow" the curvature of the rockerline and your course will be more upwind.
BUT, if you tip the rig back, at the same time you tip the board upwind rail down (to create that forward lateral resistance) the board will very quickly "round up".
It's doing exactly what the forces acting on it are telling it to do.
So, here's the "big trick".
You tip the upwind rail down to create the necessary "upwind surfaces", but you tip the rig forward slightly to "steer" the board.
If you want to go more upwind, tip the rig more nearly vertical (i.e. tip it back slightly).
If you want to steer the board off the wind slightly, tip the rig forward a little to overcome some of the board's tendancy to "follow the rockerline".
You can do this on your NTrance (or any other board).
Will you "have trouble" slogging upwind without the CB?......... right at first, yes, it will seem difficult..... but soon you will learn how to balance/steer with your rig and the board tipped upwind rail down and it won't be difficult at all.
Want to go higher..... tip the board a little more.
It's better to keep the rig pretty much upright (or somewhat forward of upright) and sheeted in only enough to give you the best forward drive.
If you sheet in too much, the rig will stall and the board will go pretty much sideways.
Give it a try on your NTrance and let us know how you get on.
Perhaps something like one of the larger Futuras will be in your future.
You need a board that's a minimum of 85 cm wide to get the best early planing.
Wider gives better early planing, it's that simple.
Hope this helps,
Thanks for your very thorough response. I'll give it another try and report back. My thinking with the Go was for added durability and full EVA deck.
I am not so skilled with a board like that and going upwind. But my trick sounds to be very close to what Roger says...
In spite of using a pretty short board, the theory could be similar.
I try to remain close the the mastfoot, the back foot only so far that my nose remains above the water. I go a little bit on the windward side. If you now apply the tack technique the board will go upwing very fast (loosing speed very fast). What I do is not to put tha sail back so radical, I keep it more upright. To win the speed and not loose it I am sheeting in when the sail is back and sheeting out as I move the sail forward...this is like pumping, but you move the the sail back and forward in the same time.
May looks funny on the water but the upwind performance in non-plannnig conditions is fine.
Wish you a good luck.
PS: To the board for early planning...if you have enough patience and you do not want to buy another board soon take something else than Go 155. It may take a bit longer till you get it running (full speed, foot straps etc.), but it will be than also a lot more fun...
I have put your directions for sailing upwind without a centerboard to practice this summer. Do the really wide formula type boards require a different technique to go upwind in non-planning conditions? The trick of tipping the upwind rail down has worked great on my Bic Techno 148 (75cm wide, 50cm fin) and has allowed me to comfortably return to the beach in offshore breezes. However, I am struggling with the same technique on my Bic Techno Formula (94cm wide, 70cm fin) board. I can't seem to get the wider board back upwind with the same ease as the narrow board. The only thing that I can think of is that maybe I am tipping the rail too much? Any thoughts or suggestions that I could try?
In my experience, it works pretty much the same on all boards.
I do remember that it's a little less effective on the superwide (=> 90 cm)
but it still should work.
What size rig are you using?
Also, you need to get well off the centerline on the wider board to get the same
roll angle due to the extra width.
The very short waterline length on the true formula board and a pretty flat rockerline
may be why they don't respond as well as narrower boards.
Try tipping your Techno formula even more, stay more forward on the board to get the rocker near the nose and mid section to "bite" a little better.
Also, what sail and rig size are you using?
I am typically using either a 9.0 Retro on the Techno Formula. Thank you for the suggestions... I will try tipping the board further and moving my weight forward.
How much wind?
With the sails you suggest (both have lots of low wind power when correctly rigged) you
can probably expect to be planing in 9 knots (maybe a bit more) and if you can plane, you may be able to go upwind "on the fin" which requires you to tip the board slightly lee rail down, to go upwind.
But you have to get fully planing first. This means you have to sail enough off the wind (beam reach or perhaps slightly lower) enough to get your board fully planing, then get into the straps and all the way back.
Once your board gets up to speed, you lift slightly with your front foot (in the front footstrap) and push across the top of the fin with your back foot (in the rear footstrap, heel down over the upwind rail a bit).
The board should rip upwind very fast on your 70 cm fin.
Hope this helps,
|All times are GMT +7. The time now is 02:21 PM.|
Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.