Cheers everybody,
I got hold of a second-hand F2 Tandem and have already fooled around on it a little, but I'm not quite sure what sail sizes to use.
We tried same size front and back and bigger sail in the back on the heavier sailor.
What certainly didn't work out was the heavier sailor in front with a bigger sail as the board seemed to sit too deep and plow the water.
In all other trials we were impressed by the perceived speed, yet the sailor in front wasn't happy with the way the sail behaved. Unfortunately, they weren't really able to explain to me in which way, so I can only guess they had to deal with too much backhand pressure but am not entirely sure about it.
For Saturday there is a reasonable forecast of 15-20 knots and I consider givving it ago with my cousin who's approximately my weight, both of us weighing in at approximately 80 Kilos (I might even be a little heavier after a cold German winter.).
Thinking about it, I now think that at the same weight the front sailor should use a smaller sail than they would usually do with the rear sailor going on their normal sail or even bigger. Correct?
What are your experiences? I would clearly appreciate any advice as we would be happy to kepp trial and error to a minimum in 9 C? air and water even colder (Wrong country, I know!).
Thanks in advance,
Sven
P.S.: I have been reading in the forum for a while and am in awe with both the wisdom and humorous quality to be found.
Good on you!
When I built mine back in the late 80's we had 2 big race sails to start with (6.2 and 7.0) with the bigger one at the rear - we were both around 70-75kgs. To be honest, didn't do too much mucking around with the sails - we were stoked just to have the thing float!!
In more recent years we have been using wave sails (5.0-5.3) but only get it out over 20 knots now. At the front we put the heavier sailor and bigger sail. The reasons being - it was easier to gybe (rear guy had to duck gybes) and when on the plane the sails felt as one (full foil).
The front guy hardly did anything - just tweaked the sail as required, watched out for obstacles and gave directions when necessary. The rear guy did most of the board adjustments.
A couple of pointers if I may...
1. Chose your partner wisely - they need to be roughly the same skill level as it will make it easier.
2. Be prepared to fall in a lot - mainly from laughing so hard
3. Waterstarts - the front guy needs to be almost fully up before the rear one starts to get up. we could uphaul it as well but this was harder for some reason
4. If you are the front sailor - watch out for catapults - if you hear a scream then a splash from the rear sailor - it is already too late - you will stop very very suddenly
5. Give yourselves a lot of room to gybe - it takes a bloody big arc and time to complete.
6. Do not attempt to jump waves! We took it in the surf once and besides the massive flex in the board, the front sailor got a nose bleed from being 6 foot off the top of the wave before the rear sailor had even hit the ramp!
7. Get video - it is awesome to look back at
8. Have fun 
I have a couple of photos and video I'll try to locate over the weekend - enjoy your trial and error!!
Chubb
Thanks a lot Chubb,
most of it is what I expected to hear.
We found waterstarting surprisingly easy once everything is arranged, gybing seemed pretty feasible, but we nevertheless failed in the few attempts we had.
Same skill level is what I'm hoping for this year.
So far I've sailed:
-with my wife, who only picjked up windsurfing becaus she felt I would be hard to bear otherwise.
-an old friend who has over the years developed a unique, not to say idiosyncratic way of sailing and a hardness of hearing, ensuring an amusing but totally hopeless struggle against each other.
I prefer sailing with my wife for the better view.
Curious that you preferred the heavier sailor in front but this might as well be down to different board designs.
I'm still wondering what happens when the front sailor sheets in properly:
Will they funnel the air, so their own sail feels bigger?
If this is so, what does it mean for the sailor in the back? Would they feel as if they could now do with more sail?
The Defi Wind Tandem Guys (now Tridem Guys) apparently always use smaller sails in front although they seem to be about the same weight, which would go along with above assumption.
Anyone else with experience, maybe even with the F2 Board?
Sven
Quick reply (winds up!) More later.
We have speed tandem and also Gemini Tandem. (Slalom Tandem in progress)
Speed tandem only sailable on PLUS 25 knots and preferably High 20's. Always used slightly larger sail at the back with two 70-75 KG sailors. With 80 KG sailor on the front used same sailed sails, but this is not the normal.
Cant gybe speed board. Just too cramped for room. Hard to water start. Found that if the front guy gets up too early, the board speed drags the back guy out of position. Timing critical.
Critical that both sailors don't try to foot steer and work against each other to get speed wobbles. Also front sailors can't sheet in too far as it kills power in rear sail. mast foot position is critical and Fin position is critical for directional trim. (A Box adjustable)
This run did 35 knots in 2006/7 - Two 5.8m sails. 75 KG on back, 80 KG on front.
Thanks a lot for your advice,
great vids. I had seen all of them apart from the run with the Koncept sails. Wow, seriously fast.
In comparison the Gemini looks like slow motion and I would guess the F2 is somewhere in between.
It's 380 cm long, 75 cm wide and supposedly weighs 18 kilos.
So we will try a smaller sail in front if sailors are the same weight and tell how we fare.
We had to postpone though as I had to admit that sailing with a cold in water below 5 degrees plus pouring rain in a 20 knot wind at 9 degrees might be an optimistic feat and a silly thing to do.
But spring is coming!
Thumbs up to everybody who scored Sandy Point this weekend!
