I found this very useful information how to set up your equipment for speedsailing. It is based on the recommendations from Kean Rogers, also know as Roo who lives in the Gorge, USA and is a very fast Speedsailor on how he sets up his own kit
Follow these steps:
1. Measure 30 cm in from the tail and measure the width of the board at this point.
2. Pick a fin with same depth as the width you measured and fit to the board. (start with a normal upright fin not a weedie).
3. Make sure the rear foot strap is mounted with the rear screw in line with the leading edge of the fin.
4. Set up the front foot strap by laying your arm on the board with the elbow bone in the middle of the rear strap and measure to the tip of your middle finger.
5. This point will be the middle of the front strap, mount the strap as close as possible to this position.Your board is now balanced to your body, the foot strap position will be different for each sailor.
Some boards don't have a good front strap position, in these cases putting the rear footstrap a bit forward helps. Between distance footstraps look for 36-40cm, 36cm for ultimate flat water speed till 40cm overpowered chop big slalom. A solution to put the straps back without an insert.
Once you've balanced your board it's time to look at your rig. If you've set your sail up using the recommended mast and according to the measurements on the sail then it will be easy to balance it out.
1. Take your fin out of the board and connect your sail to the board with the mast foot in the center of the mast track.
2. Stand the rig up and with the board on a flat surface, i.e. grass or your board bag for protection, stand on the board with your feet either side of the mast foot.
3. Move the boom until its around shoulder to chin height.
4. Lay the rig down and measure from the front of the mast at the boom to the clew eyelet.
5. Divide this distance by three and measure from the front of the mast at the boom back this distance.
6. This is where the center of you harness lines should be. Grip the boom here with both hands thumb to thumb either side of your measurement point and place the harness lines either side of your hands.
7. To get the right harness line length grab the boom in the center of the lines and adjust the lines until they are just touching your elbow bone.
8. Most sails have their max draft around 33% so this is a good balance point for most sails.
9. With the board and rig still connected, lay the board on its side and the rig on the ground, tilt the rig towards the back of the board until the gap is even between the foot of the sail and the deck of the board.
10. Your mast foot is in the right position if you take a line perpendicular to the board, i.e. at a 90 degree angle, from a point midway between the front and rear foot straps and it lines up with the center of the harness lines. If the center of the harness is too far forward move the mast foot back, if its too far back move it forward.
11. Put your fin in the board and go sail to see how it feels.
Now you have a reference point you can set the board at each time you sail, it makes it a lot easier to fine tune your equipment for optimum performance for the conditions.
Remember if you're not fast'you're last!