What determines maximum sail size for a board?

capetonian · Joined: 11 Aug 2006 Posts: 1197 Location: Florida

Fanatic Mamba 104 L 224 cm long 60.5 cm wide - max sail size 6.8
Quattro Cube 106 L 226 cm long 62.5 cm wide - max sail size 6.0
Severne Pyro 105 L 226 cm long 62.5 cm wide - max sail size 6.7
Exocet X-Wave 103 L 224 cm long 63.5 cm wide - max sail size 6.8

NOVAAN · Joined: 28 Sep 1994 Posts: 1549

Water conditions, body weight type of board. Also wind conditions. Big gusts or big lulls.
Lots of people are having more fun on bigger boards and smaller sails. Unless your in really steady winds sinker boards are a lot of work. Also if the wind drops the bigger board is easier to get back to the launch. I'm 165 lbs and sail a 3S 96 with a 4.2 Its thin and narrow in the tail and rides smooth in the chop.

NOVAAN · Joined: 28 Sep 1994 Posts: 1549

Sorry guys I thought he asked for min. sail size. I guess most of that applies to the max sail also

isobars · Joined: 12 Dec 1999 Posts: 20935

Too much sail, just like a COE that's too high, will also sink the nose. But if one can control it -- i.e., has greater skill -- a high COE (plus a tight leech) can produce some big air and extended hang time.

dllee · Joined: 03 Jul 2009 Posts: 5329 Location: East Bay

Efficiency.
You can put a 7 meter sail on a 85 liter freeride board, but you're better off with a 6 and 110.

ss59 · Joined: 10 Nov 2016 Posts: 104

Probably got this wrong but I always thought max sail size is determined by max fin size which in turn is determined by the one foot off-width

swchandler · Joined: 08 Nov 1993 Posts: 10588

ss59, I'm also of the opinion that sail and fin size must be properly matched to get the maximum performance possible. If the fin is too small, particularly with larger sails, the sail and its power are heavily compromised.

Now, considering the wavy nature of the boards highlighted, the likely smaller multi-fin arrangements on these boards is probably the limiting factor in recommended maximum sail size. You could theoretically use a larger sail, but the sail's potential is lost because it's out of balance with the fin(s). However, you could increase fin(s) size and the total fin area to achieve a better balance with the sail. The downside with larger sails and more fin area is getting the kind of maneuverability and handling you want in a wave environment.

dllee · Joined: 03 Jul 2009 Posts: 5329 Location: East Bay

Circa 1988, Doug Haut placed 2nd overall in a San Luis Res. speed trial using his 8'8" x 17" speed needle with a 7.0 borrowed sail in gusty 10-20 mph wind. His board was probably around 65-70 liters.
Fin was Rainbow Speed 7.75 that was a bit thicker than the US box.

U2U2U2 · Posted: Sun Nov 01, 2020 9:49 am Post subject:

The people who write the advertisements, going from your chart, nothing much is consistent. Far too many variables to have a written in stone specification.
What one is comfortable on, a 7.5, another could be 6.5.

techno900 · Joined: 28 Mar 2001 Posts: 4161

I have two similar boards, one 105L bump and jump and a 108L slalom. Both the same width. The 105L board is best with 5.2 to 6.4 sails (6.0 ideal). The 108L board is best with 6.6 to 8.4 sails (7.6 ideal).

It's the tail design/width and fin size that determines sail size in my experience.