Going down the mine ...

Sorry Stefan, IIRC = "If I Recall Correctly", "FW"= "Formula Windsurfing" (or Windsurfer?) class, AIUI = "As I Understand It", BIKFAAI= "But I know very little about it", IASIWUTMA= "I'm A Silly Idiot Who Uses Too Many Acronyms" and OGNTRLCA = "Oh God, Not That Raving Loony C249 Again".


Stefan, because of my job at the time I got to sit down with guys like Robby Naish and a tape recorder and ask them about technique. The guys I interviewed on surf slalom were pretty specific (IIRC) that you did NOT sheet out to slow down. The whole point was that you did not want to slow down, and the best way to keep going fast was to sheet out so your inevitable jumps (we sometimes had mast-high waves in surf slalom on the pro events) were as short as possible and you could get back onto the water and start driving again. It was understood, I think, that sheeting out reduced lifting force rather than slowing you down. The sheeting out was very brief and was done IN the air; it was not long enough to significantly slow the board and if you had wanted to slow to avoid a jump you'd have slowed BEFORE hitting the wave and getting launched. In the air you are slowing anyway (no sideforce from the fin= no forward power from the rig).

As SSailor said, "If you jump and bring the rig to windward you begin to create the lift hence the bigger air time" and that seems (to me) to underline that inclining the rig creates lift and hence an inclined kite luff could create lift.

I'm not what I'd call a hot slalom sailor but when I was doing it I beat most of the guys at the worlds (a limited-entry event with about 30+ countries competing) in a field including Bjorn Dunkerbeck so I think I was on the right wavelength.

I totally agree about keeping the rig upright normally for speed most of the time (surf slalom is a special case) although some very clever guys (Jim Drake among them) say that some classes like big-sailed Formula Windsurfing (FW) boards are happier with 15 degrees of windward rake.

Our IMCO national champ (Olympic medallist, world champ) advocates keeping the rig as vertical as possible and Jim Drake wonders whether difference in rig rake may be related to the fact that the IMCO has a smaller rig and is a heavier board. But it's interesting that in another longboard class (with an even smaller rig and heavier board) the guy who beat me in most events at the nationals (a two-time world champ and Olympic team member himself) carries enormous amounts of windward rake in strong winds and he is unstoppable upwind in those conditions.

Which may just show how complicated the whole aspect of rake, lift, aerodynamics etc is!


Edited by Chris 249

Originally posted by turnturtle Originally posted by Guest#260 FW? http://www.techdictionary.com/chatsms.html   GIWIST, ISWYM GMTA. WAEF FOAG. BFN, GF- YAOTM

Quite ... I think they have got FUBAR wrong ...

FW?

http://www.techdictionary.com/chatsms.html

 

Edited by Guest#260

Sorry guys, I didn't make it clear about the boards. I made it sound like the rig is normally lifting the board a significant amount, which I agree it does not do when you're racing along.

What I should have made obvious is that I was talking about the way you move the rig when trying to get a long jump (not a high one) in waves, when you often "hoik" the rig down closer to horizontal, and it's accepted (by even the best) that this gives you a bit of extra flight.

You tend to do the same sort of thing when chop hopping, whereas when you are say going for a forward loop you keep the rig pretty much vertical then sheet in - or I think you do, haven't done those (or any competitions in waves) since I woke up in hospital with the surgeon tut-tutting me about getting it all mixed up!

The FW guys always seem to say (IIRC) that if you sheet out when overpowered upwind, you will automatically lift off the water and crash. Again, there seems to be a direct link between rig attitude and lift.

While Stefan's comments about sail shape sound quite convincing, wavesails are flat and  they do seem to have a fair bit of vertical lift available when used for jumping. For example, in surf slalom days everyone sheeted out briefly to avoid jumps because jumps actually slowed you down. No-one said you avoided the jump by slowing down - they say you avoided the jump by sheeting out. I used to race slalom against guys like Robby, Bjorn etc and got to ask them how they did it.

I'm no Bjorn so I may be wrong. Just food for thought. This whole rig attitude stuff has some very smart people on each side!


Edited by Chris 249

Yeh im also a freestyle and wave windsurfer, and once planing with correct technique you rake the rig back which forces the mast into the board leveling the nose. the reason you will see boards with their noses up is either the person is learning or in most situations they arent planing flat out and thus the back of the board is sinking - like standing on the back of a laser and expecting the nose to stay down!