danidr wrote: ↑
Wed May 31, 2017 11:25 pm
.....I find quads quite "stiff" and not very playful. My two surf/kiteboards were thrusters and every time I use someone else's board and it's a quad, I don't like how it carves and behaves. Anyone care to explain?
I spent 5 years trying to research this very topic. In the end I came up with more questions than answers. So I gave up trying to nail down a thesis on the difference between Quads and Thrusters in kitesurfing specific applications. But as you asked, here is a summary of what I have come up with. (Again, please remember that this is for a kitesurfing specific application. Prone surfing treats thrusters the same as kitesurfing, but it does not treat quads the same.)
With thrusters the rider stands directly over the top of the board in direct opposition to gravity/centripetal force. The direction of travel IS directly tied to the centerline of the board. A thruster will not "crab" sideways. It is always traveling in line with the centerline of the board. The most stable line of travel on a thruster is in line with the centerline of the board. Loading the fins to a low degree of sideloading force spins them out instantly. The rider controls the direction of travel on a tack with the font foot. Control over the direction the board is pointing at every instant is essential to traveling in a single direction. Chop that bounces the nose of the board upwind and downwind, leads to a messy/squiggly tack line.
With quads, the rider hikes out a bit (increases to severe with more speed) and side loads the upwind fins while constantly adjusting the roll (edging) of of the rail. The direction of travel of a quad IS NOT tied to the centerline of the board. A quad will "crab" sideways at various angles according to the load of the fins/roll of the board. A quads direction of travel is not tied to the centerline of the board, and a line of travel in line with the centerline of the board is unstable on a quad. Loading the fins to higher and higher degrees of sideloading force typically result in more and more push back against the load without spinning out. The rider controls the direction of travel with the back foot and the sideloading of the fins. Chop that bounces the nose of the board upwind and downwind does not affect the straightness of the tack line.
So given the above, why will one kiter say quads are not exciting compared to thrusters and another say the opposite?
It has 100% to do with how they try to ride the 2 fin configurations. If you try to ride a quad like a thruster, it will work, but you will get the feeling that the board is just dead. If you try to ride a thruster like a quad, then you will just be spinning out the fins on the thruster all the time.
The remedy for this in each instance, is to ride a thruster like a thruster, and ride a quad like a quad. You need to approach each configuration differently. If you are locked into a single mindset, you will get nothing out of the one you do not normally ride. It took me years to figure this out. Luckily, I first rode thrusters, but quickly moved onto quads. This gave me an experience base in both while I was still trying to figure out how to ride a surfboard.
Why do I stick to the quad configuration when some of my experimentation has actually made me think less of the quad configuration vs the thrusters capabilities? - It is all because I like the additional physical effort and feedback that a quad requires and gives. At it's top end, a quad is more of a ride in a jet fighter. The top end of a thruster configuration is fun too, but just more of a race car ride than a jet fighter ride.