The kicker that started it all
The most-built ramp from my old Plans4Ramps site, reborn as a living design — pick a height, radius, and width, and the whole build regenerates to match.
Long before this site, I ran a little corner of the internet called Plans4Ramps. It was exactly what it sounds like: printable plans for BMX and skate ramps. And of everything on it, one design got built more than all the others combined — the kicker. A kicker is the simplest real jump ramp there is: two curved plywood sides, a ladder of 2x4s between them, and a skin bent over the top.
The old plans were frozen at one size. If you wanted it taller, or mellower, or narrow enough to fit the strip of patio beside the garage, you were on your own with a calculator. That always bugged me, because the kicker isn't really a ramp — it's a formula wearing plywood. So this time the plans are alive. The whole design follows three numbers, and you're holding all three.
Everything below — every cut, every screw, the shopping list at the end — is generated from wherever you leave those sliders.
One curve, cut twice
The signature move of the whole build is the radius cut, and you don't need a CNC or even a router for it. You need a string. Anchor one end of the string at the radius distance, tie a pencil to the other, and swing an arc across the panel blank. Then cut to the line with a jigsaw. A wavering cut disappears under the skin later, so this is more forgiving than it sounds.
The part I'm proud of is what happens to the offcut: nothing. Both side panels nest in a single blank, rotated 180 degrees from each other. The first arc's waste is the second panel. Cut one curve, flip your attention to the opposite corner, cut the same curve again, and the only scrap is a thin lens-shaped sliver between the two arcs.
A ladder of 2x4s
The frame is where kickers usually go wrong. Screw the cross members in wherever feels right and the skin ends up with flat spots and a mushy lip. The rule the old plans taught — and the rule this design solves for automatically — is that the curve needs backing about every six inches along the arc, and the two spots that are never allowed to float are the very bottom and the very top.
So the frame squares up off the back edge first: one member flat on the ground at the back, one plumb at the top of the back edge — its face becomes a little deck the skin's end will screw into. Then a member lies flat at the nose, its corner just kissing the curve. The rest tilt to follow the arc between those anchors, spaced evenly, each one solved so its face sits exactly flush with the radius-cut edge.
The skin is two thin sheets, not one thick one
You cannot bend 3/4" plywood to a six-foot radius, and you shouldn't try. The riding surface is two layers of 3/8" instead. Each layer bends easily, and once they're screwed down through each other into the members, they act like one stiff 3/4" sheet that happens to already be curved.
There's a detail here that's easy to miss in the finished ramp: the under-layer stops a foot short of the bottom, and only the top layer runs all the way to the ground. That kills the abrupt double-thickness bump right where your wheels first touch the ramp — the transition from pavement to wood is a single 3/8" feathered edge. The seams of the two layers land in different places too, so no joint in the riding surface ever lines up with a joint underneath it.
Steeper or mellower
Height and radius are two different dials, and mixing them up is the classic kicker mistake. Height sets how high you launch. Radius sets how hard the ramp kicks — the tighter the arc, the more abruptly it converts your speed into upward motion. At the default 16" height and 72" radius, the lip leaves you at about 39 degrees. Squeeze the same height onto a 48" radius and the lip steepens toward 48 degrees, which is a very different experience at speed.
The design keeps you honest, too. Ask for a shape that can't work — a radius smaller than the height, or a curve so long it outgrows a 96" sheet of plywood — and it refuses, and tells you why, before you've bought a single board.
Make it yours
Mine is the ramp I wish I could have mailed to everyone who wrote in asking for "the same one, but a bit bigger." Set the height your nerves can handle, the radius your speed deserves, and the width your spot allows. The cut list, the screw count, the arc's compass measurements, and the step-by-step build regenerate for exactly the ramp you'll ride.