View previous topic :: View next topic |
Author |
Message |
outcast
Joined: 04 May 2004 Posts: 2724
|
|
Back to top |
|
|
DanWeiss
Joined: 24 Jun 2008 Posts: 2296 Location: Connecticut, USA
|
Posted: Wed Aug 21, 2013 7:25 am Post subject: |
|
|
There's a kiter in MV, Brock Callen, who often rides a foil board. I saw him last summer in VH harbor and offer the following limited observations.
He wasn't fast compared to guys on racing boards but it appeared that he was able to go faster in lighter conditions than the guys using twin-tips. I've no idea what sizes each used.
After each jibe his foil lost a lot of power. I suppose that when the kite moves forward in the new window the upward moment isn't converted to forward motion as soon and efficiently as with a board. It appeared Brock leaned back to keep from lifting entirely out of the water and slammed. Not sure that's what it was about, but looked that way to me. Different kite movement might eliminate that problem, if it actually exists.
Upwind foiling has been done by Emerites Team NZ, yet they say their VMG isn't as good on foils as in displacement. Sandbagging perhaps, but my view of Brock's upwind angle versus the race boards suggested the same.
Plus the turtle thing . . . _________________ Support Your Sport. Join US Windsurfing!
www.USWindsurfing.org |
|
Back to top |
|
|
whitevan01
Joined: 29 Jun 2007 Posts: 607
|
Posted: Wed Aug 21, 2013 8:38 am Post subject: |
|
|
the AC wind maximum is based on apparent wind not true wind. so, it's actually the vector sum of the current (tide) "wind" and true wind. if the current and the wind are in opposite directions the true windspeed max. will be 23 knots minus the speed of the current. the converse is true if the true wind and current directions are in opposing directions.
so, when they talk about the wind maximum on the broadcast, they are talking about true wind speed, and notice that it changes every so often. That's because the tidal velocity (velocity takes into account both speed and direction) is constantly changing.
they dropped the wind maximum by 10 knots or so after the guy died on Artemis racing. I think it is fascinating (being a former sailboat racer and one time Hobie 14 East Coast champion) stuff. Just wish both boats would hold together so we could see a complete race with both boats finishing.
Really, really looking forward to NZ beating Oracle in Sept. I'd love the Cup to be in American hands, but not Larry Ellison's. |
|
Back to top |
|
|
dllee
Joined: 03 Jul 2009 Posts: 5329 Location: East Bay
|
Posted: Wed Aug 21, 2013 6:19 pm Post subject: |
|
|
I watched as a kitesurfer on a foil moved from PuntaLasMarias in PuertoRico down to Condado, then back again in less than 40 minutes, which should beat any well powered Formula sailor. Maybe 3 miles each way.
Some Formula guys were watching from LasMarias, and mentioned it looked pretty efficient.
Currently, in SF Bay, it's hard to beat the 4 fin kiteboards using 40cm Tectonis fins and Slabs or whatever boards, if the winds are steady and always above 15 mph. |
|
Back to top |
|
|
outcast
Joined: 04 May 2004 Posts: 2724
|
|
Back to top |
|
|
dllee
Joined: 03 Jul 2009 Posts: 5329 Location: East Bay
|
Posted: Thu Aug 22, 2013 12:32 pm Post subject: |
|
|
What can we gleam from this?
AC has better top speed.
Kiteboard accelerates quicker.
Longcourse, GoldenGate to Alcatraz, no jibes, favors AC.
What about a typical Formula course? That requires 2 tack's a lap, and at least 3 jibes a lap, usually 2 laps. |
|
Back to top |
|
|
outcast
Joined: 04 May 2004 Posts: 2724
|
|
Back to top |
|
|
dllee
Joined: 03 Jul 2009 Posts: 5329 Location: East Bay
|
Posted: Thu Aug 22, 2013 4:24 pm Post subject: |
|
|
15 millions bucks can be spent to edge out 3,000 bucks. |
|
Back to top |
|
|
outcast
Joined: 04 May 2004 Posts: 2724
|
|
Back to top |
|
|
whitevan01
Joined: 29 Jun 2007 Posts: 607
|
Posted: Fri Aug 23, 2013 11:19 am Post subject: |
|
|
outcast wrote: | Did you see this.?
Kai on a raceboard Vs 72....they just reel him in like he's barely cooking
! |
keep in mind that this video is an advert for Red Bull. Of course, they set it up to be exciting and to make sure that the more expensive boat they sponsor beats the least expensive "boat" they sponsor! |
|
Back to top |
|
|
|
|
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum You can attach files in this forum You can download files in this forum
|
|
|