View previous topic :: View next topic |
Author |
Message |
outcast
Joined: 04 May 2004 Posts: 2724
|
|
Back to top |
|
|
coachg
Joined: 10 Sep 2000 Posts: 3550
|
Posted: Sat Feb 23, 2019 11:54 am Post subject: |
|
|
outcast wrote: | Just get a foil.... |
You would think? Except some of these numb nuts are putting 10 meter sails on foils??????
Go figure.
Coachg |
|
Back to top |
|
|
grantmac017
Joined: 04 Aug 2016 Posts: 946
|
Posted: Sat Feb 23, 2019 1:04 pm Post subject: |
|
|
Raceboard sails can use 550s I believe, but just like the foil racers running 10m it's not going to get you going in less wind, just add a few degrees of angle upwind. Kind of like how a formula board will plane about the same with a 9.5 or 12m but the 12m will have better angles.
RTZ seems to want to stuff the biggest sail on his beginner board rather than learn enough to ditch it for something that'll actually work in light winds. |
|
Back to top |
|
|
ss59
Joined: 10 Nov 2016 Posts: 104
|
Posted: Sat Feb 23, 2019 2:32 pm Post subject: |
|
|
grantmac017 wrote: | Kind of like how a formula board will plane about the same with a 9.5 or 12m but the 12m will have better angles.
|
does this mean that if there was enough wind to plane with either a 9.5 or a 12m, the 12m would be able to point higher??? My logic would have thought it was the other way around.
Could you explain this for me, please? Do bigger sails point higher and if so, why? |
|
Back to top |
|
|
dllee
Joined: 03 Jul 2009 Posts: 5329 Location: East Bay
|
Posted: Sat Feb 23, 2019 3:17 pm Post subject: |
|
|
Pointing high and reaching low requires lots of power. Just planing slightly off the wind needs the least sail power.
Typical steady 17 mph day, you have Formula on 11 meters, slalom dudes on 8 meters, freeride guys zipping along on 6 meters, wave and freestylers on 5.3's, and lightwind foilers on 4.7's. Race foulers on 8's. |
|
Back to top |
|
|
grantmac017
Joined: 04 Aug 2016 Posts: 946
|
Posted: Sat Feb 23, 2019 3:32 pm Post subject: |
|
|
Assuming you change only the sail size, not design or anything else, the bigger one will point higher until it becomes too large to control. |
|
Back to top |
|
|
DanWeiss
Joined: 24 Jun 2008 Posts: 2296 Location: Connecticut, USA
|
Posted: Sat Feb 23, 2019 6:41 pm Post subject: |
|
|
Big sails develop more power than smaller sails but aren't always faster. We get upwind mostly through speed of the water across the fin, not because of our sail size per se. Sail the smallest sail you can use for the particular application.
Learning to shortboard with a large sail is a potential disaster because large sails also come with drafts that move a greater distance. To control this, large sails require very precise tuning and very specific masts -at least most huge cambered sails push the sailor around when not tuned well.
As others say, FW racers must use the huge sizes to achieve downwind speed and angle. No-one interested in a few degrees needs that nonsense. _________________ Support Your Sport. Join US Windsurfing!
www.USWindsurfing.org |
|
Back to top |
|
|
jingebritsen
Joined: 21 Aug 2002 Posts: 3371
|
|
Back to top |
|
|
grantmac017
Joined: 04 Aug 2016 Posts: 946
|
Posted: Sun Feb 24, 2019 1:04 pm Post subject: |
|
|
Isn't something like ~30% of a formula sail dedicated to JUST drag reduction? IE: not contributing to planing power but only an effective part of the system once lit up?
I know raceboard sails are if anything more powerful at 9.5m but can't hit the speeds because of their drag penalty (which matches the board's capabilities). |
|
Back to top |
|
|
DanWeiss
Joined: 24 Jun 2008 Posts: 2296 Location: Connecticut, USA
|
Posted: Sun Feb 24, 2019 3:27 pm Post subject: |
|
|
grantmac017 wrote: | Isn't something like ~30% of a formula sail dedicated to JUST drag reduction? IE: not contributing to planing power but only an effective part of the system once lit up?
I know raceboard sails are if anything more powerful at 9.5m but can't hit the speeds because of their drag penalty (which matches the board's capabilities). |
Sort of. The shaping of FW sails are intended to produce speed upwind by reducing drag through the ability to make the leading entry fairly lean while keeping the draft stable. TFW sails tend to allow greater rotation through only adjusting the outhaul, whereas Raceboard sails rely on the addition of a running downhaul to control shape.
As for raw power, the measure is more of useful power. A Raceboard sail develops more rotational lift, meaning it feels like it pulls on your back hand more easily, but the Raceboard's coffin-style rails and long waterline turn that rotational lift into forward movement. A FW board develops far less rotational lift since that impedes a balanced feel from the board and fin when planing. So it's hard to say which 9.5 develops more power, but it's easy to mistake rotational lift for "power" as we feel the sail.
Remember, the pros used 6.6-7.2 in the 1980s when racing longboards. Those sails pulled like tractors but could not get out of their own way when planing, at least compared to the new sails.
So that's the key: Planing hulls demanded that sail sizes to grow based on increase of the downwind leg's angle. We don't need much more than 8.0 and 12 knots to rip upwind but that 8.0 will never generate the lift needed to plane really deep downwind in the same wind speed. Therefore, since sailors remained the same size, the larger sails had to be shaped with the ability to depower upwind (including greatly reduced drag per square meter) so as not to overpower the sailor yet change the entry rotation and twist off to keep speeds high in the variable apparent wind angles encountered when sailing deep. _________________ Support Your Sport. Join US Windsurfing!
www.USWindsurfing.org |
|
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
|
|
|