im not the guru but i have a question.
i wanting to get a speed sail for light winds 15 - 25 knots my 6.0 does not get us trimming i was wanting somthing that will get us thumping along.
the problem is that my mast is a 430 imcs 21 2.0kg i have large extention to suit the 6.0 but i have been warned not to have it out to far because of breakage.
i was wonderin would it be better to get a Size
Size 460 imcs 25 2.1kg
or
Size 490 imcs 29 2.4kg
for light wind my boom
goes out to 220
i seem to notice there is people running 6.5 and have trouble plaining in light conditions.
there a guy running a large sail for wa windsurf and another few blokes ripping it up but i didnt get the oppotunity to see what gear they were using..
whats the max/ min sail size you can get on a 4.6
and the max/min you can get on a 4.9
im just worried if i get a 4.6 it will limit us.
I run a 7.5 KA Koncept on a 4.6 with 24cm extension. Will get me going in 12 knots on a big board. I have a spare 490cm and a 7.6 to fit if you wanted to give it a try.
Mast sizes can vary a fair bit between brands.
Normally you can rig up to a 7.5 or 7.8 on a 460.
since your boom only goes too 220 no put getting a 490 mast as your boom well be to small for any sails that would take a 490 eg my 8.5 rigs on a 490 but takes a 228 boom.
Surprised your 6.0 takes such a large extension how old is the sail and how much ext are you using.
ta Vando
i'm 105kg and i would run a 6.4 in 15+ knots.
although i agree with the other that 7.5 is a good size for those winds i am with vando and am curious as to what sail you are using.
I'm about 75kg (in summer anyhow 
) and would usually use a 6.6m KA Koncept in the winds 15-20 and a 5.8m Koncept in 20-25 knots.
The 6.6m Koncept works best on the 460 mast (same mast as my 7.5m Koncept) but a 6.6m KA Koyote (no cam freerace) works best on a 430 mast and has great performance. Might be worth considering?
I always buy second hand and have 1 mast 1 boom for 4.5-7.5 cos I search the sail stats before I buy. Find them here: mytrims.com/sails/list.asp 
The 2010 Koncept sizes change a touch. The 7.5 is now a 7.3, some area taken out of the head and more shape added down low. It sets on a 460 (luff max 481) and max boom 202. The 8.3 will work on your 490 with 20cm extension and max boom is 215.
The proto 7.5 gets my 90 kg's planning on a 69 cm wide board in 13-14 knots depending on how much energy I have to pump..
There is also the new KaRace coming around Xmas. There is a 7.9 which runs on a 460 although the actual dimensions are still being finalised. Boom length should be under 220. I have only used the 7.1 proto, it,s a 15 knot plus sail for me so I would think the 7.9 would drop the planning threshold a couple of knots. It has more top end than the Koncept due to it,s amazing draft stability.
Regards Martin
sweet guys that cleared up a few thing that i had i wount borrow a sail incase i break it i think ill stick with the kit i got for high wind ...
one more question.
this is in realtionship to board strap positions and fins
Some boards have a central back foot strap is this for turnability? Does it decreace the ability to hold rail in high wind. for speed sailing do the quickest boards have 2 back footstraps ?
