Howdy. I'm a new recruit to speed sailing in 2012, Bender is to blame. Bender has given me good advice on setup, in particular, get a better fin - on the list.
I'm 95kg and 6'3". I'm a slowpoke in this forum. My goal is to crack 40kts before I'm a pensioner.
My best speed so far is 36kts last summer with a 5m wave. I did set it up "racy", with maximum twist. I think a lot of this had to do with the water. I beared away on a nice flat section near the end of the sandbar at Safety Bay. Since then I have had a few good days with my Koncept 6.6 and my best has been 35kts in a westerly at Australind. I didn't feel that comfortable though as although the chop was small, it was unsettling my board.
So finally to the point. What I'm wondering is do some people have a style that achieves better results with smaller twin cams on a broad reach, or does this just mean there just not reaching their potential? I think I recall reading many years ago that a RAF sail can be just as fast off the wind. Of course the fact that I'm a tight arse and twin cams are cheaper has nothing to do with it
Cheers
Rob

At your height and weight the correct board / fin and sail is going to be key to achieving a 40.
For example on the Pinnaroos I am 1.76m and 75Kg I use 4 cam sails rigged on a skinny mast and wear a weight jacket to be able to compete with Pointman who is more your size but likely to be riding a bigger board and rig set on a SDM.

My sail will flex off at the top to allow me to carry more area but not get unsettled in the gusts ( the extra 5Kg of weight also helps this).
You need enough power in the sail to get you to overcome the resistance of board / fin drag, chop and inertia (resistance to movement caused by mass).

You can sail fast on smaller gear if you have everything trimmed correctly to minimise the drag (talk to Stroppo on the Coastal speed team) but generally this only works on flat water unless you are very skillful.

The main things you are looking for in WA speed conditions (where most runs are short) is a set up that gets you up to speed quickly.
This usually means so much sail that you struggle upwind (an adjustable outhaul helps here), a board that is fast but not too small so that you get planing quickly paired with as small a fin as you can handle getting up wind with and not spin out in the chop.
The most important component (and rare in WA) is flat water combined with 25-30knots of wind.

As for type of sail... In the right conditions a smaller 2 cam sail will do 40 easy but in real world conditions a 4 cam sail will generally have more depth and stability for broad runs.
Having a 2 cam sail with an adjustable outhaul lets you use the boom as an extra batten and really allow it to have depth for power off the wind.

Board trim is a balance of fin size and strap / track position and varies with rider / board / sail.

Slowy always talks about being light on your feet (taking as much weight off the board as possible, a technique that is hard to get a feel for)

35knots at Australind is good going but you will probably need to go hunt down some flatter water for a 40.

If you look here you will see the select few who have managed a 40 in WA waters http://www.windsurfingwa.org.au/index.php?option=com_content&view=article&id=57:wa-10sec-speed-table&catid=1:latest-news&Itemid=29

Thanks for your post Lao Shi, useful feedback. Interesting comment about being light on your feet, I try for this in marginal conditions, but I find I have a fair bit of back foot pressure when I'm going for it. I guess this shows I need to put more effort into rig setup and technique, whereas ATM I tend to just do it.....

Efficiency is the key. You have a limited amount of power that can be applied to forward movement and overcome drag.

The problem is that the way one goes about finding that efficiency varies enormously with the conditions. The variables are many: Broad or tight angle, Rough or smooth water. Regular or uneven chop. Steady or gusty wind. Strong wind or lighter wind. All these variables, and more, can require a different approach and different equipment. Sometimes subtle, sometimes major.

For a given venue and conditions, others will have probably already shown the way for efficiency. Check out the way the faster people do things in your local conditions and start from there, taking into account if they are similar height and weight to you.

Remember it is the total combination of sailor, board, fin and sail that all needs to complement each other for the conditions. There is no one 'magic' bit of equipment or technique. It is the combination that counts!

Some of the variables have already been addressed by Lao Shi. I would add that fighting to hold the biggest sail possible is often not the most efficient solution. If the only way you can keep control of that large sail is to tune it to lose efficiency, well......., you will lose speed. Or another example, if you need to use a larger fin to keep control of a larger board or sail, you will lose efficiency.

Generally speaking, no cam sails can not be set as full and stable for deep downwind power as cammed sails, but this will not always be a vital factor. In really strong winds, a small RAF sail may have all the power you can handle and being able to be in control and apply that power will be more important for maximim speed.

Rob good to here you want to improve if your a tight arse [ no offence] this tip will cost you nothing but energy try holding your stance when you do your runs by making your frame stiff as you can so no energy is absorbed through your body and it goes straight out through the fin the water needs to be flat as possible so you you dont eat it. It is tiring to do this but no pain no gain in the gust with this approach the rig will transfer the power to speed with minimum loss of energy hope this helps !!!!!

Stroppo, Sailquik
Thanks for the tips guys, great advice. Hopefully I can put into action soon
Cheers