Working out kickers
Been thinking about and trying to work out some rough guidelines on the best dimensions and ratios to use when building a kicker for a couple of months now.
The question pops up on SurfingDirt Forum occasionally and it needs to be in the ATBA-UK Track and Jump building guidelines anyway.
So, after a late night session yesterday, and some summing up today here’s what WSG7, Brindy and me have come up with:
- Kicker designs usually start with, ‘I’m going to build it this high…’, so that’s where we started. Everything would have to be based around the height of the kicker.
- The radius is the next thing, and usually the hardest bit to get your head around. We would need five simple ratios to give us Really Mellow, Mellow, Medium, Steep and Really Steep kickers.
- It would be handy to know how long the kicker is going to be so you plan how much wood or mud you’ll need to build it.
Kicker Ratios
Working from deciding what height you want your kicker to be, the radius for a Really Steep kicker is 1:1.6, a Steep kicker is 1:1.8, a Medium kicker is 1:2, a Mellow kicker is 1:2.3, and a Really Mellow kicker is 1:2.6
Length
We can work out how long the kicker is going to be with this simple formula: height / TAN (angle in degrees) = length.
Summary
Here’s WSG7’s handy Kicker Measurements Table.
Next…
Next I need to put some more time into:
- Doing the calculations that figure out where a rider will land, how high they will go, and how much time they will spend in the air, on each kicker and different speeds.
- Checking the model against the measurements I took of real mountainboarders going over a real jump ant Ironsides.
- Do some thinking about landings and where they should be for each tracjectory to reduce the Effective fall Height.
- Get it all written up in a way that makes sense so it can go in the ATBA-UK Jump building Guidelines