I have moved this thread from another beacuse I think it needs a tread of its own rather than getting mixed up with another subject.

oldMXer said...

Gizmo said...

oldMXer said...
have often contemplated using a traveler system with the uncut windsurfer sail and standard wishbone boom setup to get rig closer to center or past., feel there is tons of performance to be found without having to modify anything. from what i have read an iceflyer acheives very significant speed but may not point as high as a cl5 or mini. might this be overcome with a simple traveler system, yes? recently there have been statements about landyachts applying significantly more downhaul than a standard windsurfer setup, could someone explain how that is possible? most ws sail modifications take some luff curve out suggesting less downhaul is applied to set shape with mast. is the modded sail fuller than a properly downhauled, outhauled standard windsurfer sail?

A traveler system on a standard sailboard rig land yacht would make little difference. The biggest problem with that type of rig is you reach the rigs 'top speed' early and you wont get it any faster. Its a bit like driving a car and only using second gear.... You are speed limited.
A conventional land yacht sail like used on class5 and Mini 5.6 yachts works like a car auto transmission, as the sail is sheeted in the rig flexes, down haul is increased (moving the draft forward) and the sail flattens off making a more efficient at a higher speed.

I have read the tranny analogy over and over, but which generation of sails is that based on? Have experienced the second gear feeling with some yes, the ones that are the oldest in my quiver (think they are late 80s, early 90s). Visually you can see they are fuller, maybe because boards and associated gear at the time were heavier or lacked performance. What explains the success achieved by the iceflyer/windflyer with an unaltered sailboard sail? From what I have seen they don't appear to be speed limited. Landyacht also posted a thread titled "petes windsurfer rig" a while back, reads like it performed decently at a large venue.
There is plenty of money involved in advancing windsurfing performance (can same be said about landyachts?), plenty of used sails out there available cheap, and with the newer materials used it is going to be harder in future to modify without dollars lost. Please try to persuade me not to stay this course.

EVERY rig / sail, even wing masts have a terminal top speed when it just wont get any faster. EVERY rig has an ideal wind speed and this is caused by the draft of the sail, the profile, down haul & out haul tensions, batten tensions rig tension, mast flex etc.

Water sailors rig their yachts on the beach and set a lot of things there and only making small adjustments out on the water, but they are only working in a very narrow 'wind window' that is lowest and highest wind the sail will experience that day.

Land sailors do similar BUT the 'wind window' for land sailors is much wider, normally light wind speed when you start rolling going through to high speed apparent wind. Wind at 60-80km/h are working on land yacht sails .... which is in-fact 'storm' level for level for water sailors and 100km wind is hurricane force.

So why would you expect to get a single sail to work well in ALL winds from light to hurricane force? You cant.

So if you want to use water sails on land yachts you accept they have narrow 'window' of use or modify then to widen that usable 'window'

YES sail board sails work on land yachts but they do have limitations.