Hi, With sail recommendations on boards what is this based on, width, length, fin, sailors weight....
Im 105kg and im looking for a board which will carry my 4,5 in high winds, but most boards that recommend this sail size are way under the rule off litre per kg for my weight...
So is it ok to go less volume board than your weight???? "say 95ltr"
My smallest board is 110lt..
Thanks 
I use 4.5 on my 105L and it works fine, I used it on 113L fanatic eagle and it worked well too.
Use smaller fin for smaller sail and it should do the trick...
think of it like any other sport- do wake boarders, skiers, surfers, kiters etc use boards even remotely close to a litre per kg "rule". Basically that rule is just for smallest gear "easily" able to be uphauled in that you wont be up to your waist in water. You can go as small as you want, you just need consistent wind.
I'm just under 100kg and my smallest board is 63L. At 105kg safely look to around 90L as your smallest board. For 4.5 conditions try not to go wider than 60 wide.
imo that's a relative statement about width... I see a lot of freestylers using even 4.0 on a 100L board about 63cm wide... if he has 110L board he coudl try it with let's say 24cm fin and see how it behaves, if it feels to big, try lending a smaller board to see, if it suits you.
My board is 62.5 and it works very well with 4.5, but when its way overpowered it starts behaving to lively and bouncy, then it's time for a smaller board....however I'm talking about 35knot or higher gusts...
Yer, you can use a 4.5 on a 300L board if you want, anything can be used and work.
Freestylers mainly looking for flatwater and short runs where control isnt an issue.
I have no idea of Bigkym's ability, reasonably able sailor at 105kg will master a 90L board pretty quick and enjoy it more than bouncing around on the big board. That said there are plenty of guys at our local that like to stick it out with their bigger boards, however 30knots arrive and the number of guys on the water drops dramatically.
At 105kg I wouldnt be looking to go to 4.5 unless wind is a consistent 30.
I guess my point is dont use weight as an excuse to avoid small gear- it can be so much more enjoyable, just be careful on picking the conditions you use it in.
I have a 4.5 sail, not much skill (been sailing a few months only, sussing the straps and harness at the moment, though have been sussing these orrible things for a couple of months now!) and a 160L board..... what kind of wind do I need to use the 4.5? I find myself always using my 6M sail..... is this my destiny? I weigh about 77kg. Any advice would be be appreciated.
As mkseven says, once you have enough wind for a 4.5, you don't need a formula for board size, it's just about what the water is doing, and what you want to do.
At your weight, something 75 -85 litres will work nicely in 30 kts. MOst of those are wave boards, but in theory you could be doing speed runs at the Pit using a wee board and sail too.
Thank guys, i have a 115 and a 110, i want to replace the 110 with either a
105 or 95, with winter just around the corner it cranks here in SA, but the conditions
are knee shattering chop in the Gulf, so bigger boards aren't pleasant sailing...
I have borrowed a 92 with my 5,3 in 30+knts and it felt awesome but the board felt very flighty
and i had to use my weight to keep board on the water.. “great for jumping” 
Neil Pryde use there wind range on sails based on a 80kg sailor, so with sail ranges on boards
is this the similar or just marketing tool!!”so ya have to have more boards”,
especially with some off the wind ranges in some sails.....
and obviously the differences between a 60kg or 100kg sailor..
each size board will have its sweet spot with sail size. A 90L bump & jump board with big rider will be about 5.3
Some boards naturally feel flighty due to their bottom shape. But in big wind both width & length will get flighty & knocked around. To fix this either smaller fin, move mastbase forward, move straps forward or adjust sail set for more downforce. I find i dont mind a little bit heavier construction of these boards too for strength & control & comfort, no need to go latest & lightest.
Thanks
i use the same board sail range as you 130L-7m etc. , not sure that height plays a roll to as most blokes that are over the 100kg mark are over 6ft+,
im 5,10 so not sure that makes much difference, anyway due to a few repair issues on my 110, ”2mths out off action”sick off using the 130 in cranking wind, i went an got a 115,
now ive ended up with 2 boards the same size, so i was thinking about the 95ish size to be
a good gap between sizes e.g. ,130,115,95... but was concerned about going under the weight/litre etc.. and wether its worth 2-4cm around a board is worth it.....
so thanks for ya help
Most guys that have a 4,7 need a 4,2. so i got a 4,5 thought it was a good compromise...,
Less gear=Less confusion
Right gear, good times 
Hi Kym, have you tryed using smaller fins, I always run a 117 litre freeride board, but am a bit lighter 82 kg at the moment, I only use weed fins as my condition always need them but they sit the board down on the water heaps better, I always run
6-7 cam with 36
5-8 cam, 5-5 and 5-0 wave with 30.
5=0 cam, 4-7 and 4-2 wave with 24.
my favourite is the 5-0 Kobncept with the 24 fin
I don't have any issues with the 4-2 and small 24 fin in onshore surf.
will be up your way soon for a sail and hope to have a blast with J and Koshi.
Just a question about sailor weight. Does a heavy guy experience the same volume-weight significance as a light guy ?. Example: BigKym current board is 110L. That's 5L+ over his weight and he would like a smaller board (under his weight) to handle 30+ knots. Me, I'm 68kg, and use an 85L board is no worries in 30+ knots. That's 17L volume-weight. There is no way I would consider getting a 60L board at the moment.
jh2703: right on about the boom. That's my lesson for this session is boom height. I have my boom very high now. I can point up wind more and go faster. I only lower it when under or over powered.
anjroo: That is a very small sail for your level. While you are beginning, I you just need to pick your condition. Going out in high winds won't allow you to learn. In 30+ knots, I suspect you will be going along totally sheeted out while standing on the mast base and heading down wind !. I know this, as I did that too when I was learning (my first board was a 148L Bic Techno2).. Good fun, but beach walking a 150L board with a sail connected to it up the beach in 30 knots gets a bit tedious after a while 
Jimbob: no worries :). Look forward to it. Pity about this bloody weather though.
J
older boards that are narrower for the volume, compared to current boards are far better in choppy conditions.
my f2 is 110 litres is 64cm wide with narrow tail, my fanatic is 111 litres is 69cm wide with wide tail.
when wind gets to 20+ knots my fanatic starts going airborne and i keep spinning it out.
in same conditions i am cruising on my f2.
the modern short/wide board will plane + point better however.
