Hey!
I got myself a used formula kit just this month and have some sail size questions for all you experienced formula sailors!
The kit consisted of an Exocet Warp (2011) board and two North Warp F2011 rigs, one 10sqm and one 11sqm as well as a long carbon boom. I am just 60kg while the guy who owned the gear earlier was around 90. My initial plan was to sell off the 11sqm rig to get one around 8sqm (or just use the 10), but I was wondering if the sail set up I have could work? I will mostly be sailing in light winds but want to be able to sail in up to 20kts of wind speed. The main concern is that selling the 11 will make me need a lot more wind to get on the plane!
I should probably also detail that I will be using the formula board for upwind and downwind sailing, coming from dinghy sailing it is that part that I find the most fun!
Thanks in advance 
Swap the 10 for a 9, that is a better size, or perhaps a little smaller. I had that board, or maybe the one before, I have since given up formula. My two cents don't go too small, thinking you will be able to handle lots more wind. After a point it gets counterproductive with a small sail, the footstraps are still out on the rail, and you may still have just the one big fin. You still need to remain balanced and in control. The key to handling more wind is skill, and choosing a venue with a suitable water state. If your racing you will want to be competitive in light winds so you may still want the 11, otherwise just use the 9. I also put a double chicken strap on the board which was very helpful.
Well I started Formula 6 months ago, I weigh 70kg. I only have a 10m and struggled at first to cope but now I can use it in 15-18 knots without crashing. I was only ever going to have one sail BUT as I get more comfortable with it I'll go bigger. I would keep both sails and build up to it, if you go too small you will struggle to get on the plane. A couple of guys at our club use 9 m and go really well and are around your weight. It's a long road with Formula but well worth it once you develop your technique. Also I agree with chicken straps for downwind reaching, they just make life so much easier while getting used to it.
At 60 kg's, unless you're a world class windsurfer now, you cannot possibly pump an 11 meter sail to plane up near a 10 meter sail.
Just like a 90 kg guy can't pump a 12 meter onto a plane, compared to an 11 meter sail.
Dump the 11, consider an 8.5, which will get you planing in winds of 11-15 knots.
Also, consider a 62 cm sized soft flexing fin.
I"m 71 kgs., and often use a 6.5 cambered sail on F-162 or 67, for days it's nothing near shore, but 13-19 outside in the wind and chop.
Ditto at 70Kg's i only use two sails 10.0 which is my limit and TBH i don't use that much and a NP 7.2 which i love and for me is perfect.get a lot or comments about how its to small ect but i love the feel and it just works? and that's on with a 161L board.
Wondering what sails you already use?
Are you just starting out?
I thought maybe try your largest regular sail and see how you go?
Smaller sails work fine on Formula.
GBR 451 won a Cal Cup race here in Berkeley two year's ago with a 7.9, on a day with breeze around 13-20 mph, against 11's.
Yes, there is pumping involved, you can't just stand there and hope it get's you going.
I have a Formula board, but am far from experienced with it. So this is only from what I have found personally.
I weigh around 100kg's and am intermediate at best.
I have a 10.7 RS6, which I find to be a big and cumbersome sail on the formula board. I expect that this is because on all the occasions I have used it the wind has just been too light. Last time I used it I broke my carbon extender I think from trying to pump the board onto the plane, and had a fairly long swim back towing my rather heavy gear. Other times, I felt like my back would break, just from holding it up, let alone if I needed to uphaul it. Old kit I know, so perhaps the newer stuff is better. I have strangely however, had a few good days using it on my old race board, in really light wind days?
I have had a lot more success with a 9.5 evo11 on the formula board. I have had a lot of fun in windier conditions and have for a change been amongst the first to plane in the group I sail with, which is very rare indeed. About a 59cm fin I think.
What I have found with the Formula board is that it is all or nothing kind of sailing. Fully committed and feeling moments from disaster personally.
I have recently picked up a JP Super Lightwind, and on the one occasion I have it planning although definitely slower onto the plane , I was blown away by just how easy it seemed in comparison. I am looking forward to actually trying the two board side by side to see if this is actually the case.
Also, something to consider with Formula sails, I had for a while a 9.0m North Warp 2005 Formula sail, which was a high wind sail. This was very different form my other sails, as it was much flatter profile. I am sure an 8.8m North Race sail I also had at the time was much more powerful.
Certainly worth investigating, as there is a lot to be said for getting onto the plane that early. Just be ready to fully commit and hang on in the gusts, especially when you need to head down wind!
If you are from a racing background and sail "up" and "down" wind, then definitely hold onto the 11m.
Once you have your strength/technique sorted out, you will use this sail all the time and pumping will not be an issue at 60kgs.
Getting fully planning in 6 or 7 knots will not be a problem.If you want 2 sails, then maybe selling the 10m and getting a 8.5 or 9m would be the way to go.
With correct tuning and technique you will be sailing in surprisingly strong winds.
Formula requires correctly tuned sails and technique, and then the world is your oyster....
Not sure where you live, but rocking up to one of the events is always a good way to improve really quickly.
Once you have experienced being powered up all the time, it is very hard to go back...
Cheers
Thanks for all the replies, I have decided to keep the 11 and try to get hold of a 9 to replace the 10! It seems like the previous owner agreed with those of you talking about double chicken straps as those are already in place
