"Riding it off the fins" is referring to side loading the fins. This is very important as you want to push against the fins sideways to "crab" the board upwind a bit. Or rather, a quad will not be traveling in a straight line along the center line of the board. Whether or not you use rail pressure (roll) depends on board speed vs fin area/height. Average sized fins at low speed require some rail pressure to assist in developing sideways push (lift on a vertical wing). But at higher speeds, trim the board more flat (roll, not pitch) for more efficiency. When you do this, you create a fedback loop where you are reducing resistance to forward motion by flattening the board (and not making so much of a wake), and then going faster which puts more water speed over the fins, which in turn produces more sideways push (lift) from the fins. This eliminates the need for using the rail. That said, it is somewhat uncomfortable to load a kiteboard in this manner if you do not have slalom (large boards/fins) windsurfing experience.jonysan wrote: ↑Thu Nov 22, 2018 11:22 pm.....is a 5'4 Quad fin, fairly narrow, slightly heavy, dart !! it goes up wind like it's on rails, using a combination of keeping a good length of rail engaged and two of the back fins engaged, so basically using the rail and fins, ( forget that "riding it off the fins" rubbish !) keep the nose down, so you engage more rail.
Quads are very complicated to maximize. But don't let that scare you away from them. I actually recommend getting good at using a quad system first. Then later, switch to a thruster with dedication (don't give up because you don't like it). You need to learn both to see which is best suited to your particular approach.
Though I use a quad exclusively now, my extensive experimentation has shown most boards are better in a thruster configuration for getting upwind. But you have to ride the thruster with a more "over the board" stance as opposed to a hiked out stance on a quad. In addition to being directly over the board on a thruster, you also want to calm the nose down and make it point where you want to go. Do not side load the fins unless you want to break the tail free. All of my same day experimentation showed I could point higher on a thruster than I could on a quad (same board[s] with 5 fin slots in much of my experimentation).
Though it is not a completely fair comparison, kite raceboards had almost completely converted from quad to tri (thruster) at the end of that sport. Then hydrofoils took over. So there is some evidence that thruster is better for overall kitesurf performance.
But just like "strapped vs strapless", some opt for the lower performance of strapless for the challenge, or other factors. So try both and decide how you like to ride.
My reason for preferring quads is:
1. I like the feeling of hiking out on an upwind tack
2. I like the increasing load and sideways push on a quick cut back that I can get with a quad, but not with a thruster as I would have to stand over the top of the board and not let the tail break loose.
3. I like to slash and throw the board sideways, but also hook up the board sideways on a quad - on a thruster you have to make this into 2-3 steps instead of one since you need to get over the top of the board again so the fins hook up.
4. I like to go fast through chop, and the quad allows me to not care so much about the nose bouncing around and just focus on the sideways push from the fins - on a thruster I would have to put all of my attention into calming the nose down through chop.
To me, #4 means more speed in sections where everyone else on thrusters has to slow down.