LIPARC
DE EN
v 1.0 Disclaimer Open constructor
LANGEN

Dirt / Slopestyle / MTB Kicker.

Spent too long sketching kickers in CAD. Here's some math for you.

LIPARC draws dirt/slopestyle/bigbike kickers with you from one measurement — the height.
Radius, takeoff angle, and length are derived. Validated against real kickers.

Start construction What is LIPARC
SECTION · K-01
STYLE · TRICKJUMP
H2.40 m R4.15 m α61.0° flat0.30 m
SCALE · 1:50
Side section of a dirt / slopestyle / MTB kicker. Height 2.40 m, Radius 4.15 m, Lip 61.0°.RadiusFlat-SpotH · 2.40 mL · 3.77 m
Kicker
01 · WHAT

Idea

One measurement defines the whole geometry.

For example, the kicker height can define everything else. Radius, tangent, lip angle, length — all derived. The one measurement you usually already know.

01

Geometry engine

The tangent to a circle is unique. From height and radius the takeoff angle falls out deterministically. Or the other way around.

basiscircle · tangent
02

Speed as a check

A speed engine runs in the background. Thanks to a ski study we get rough g-force values. The engine warns about tight kickers. But trust your eye!

μ0.02 · 0.04 · 0.015
03

Flags + gut feel

Every construction emits codes. Take a look — they might just be right.

schemasev · code · msg
02 · INPUT

Fields

Five fields.

Every input field carries its key, its unit, and its range. Values are validated live; invalid combinations are rejected, not smoothed over.

#
Field
Description
Unit · Range
01
Kicker heightH · height
Lip height above ground. Primary measurement.
m · 0.50 – 4.00
02
RadiusR · radius
Curvature radius of the kicker.
m · 1.00 – 10.00
03
LengthL · length
Derived from H and R. Overridable.
m · derived
04
Flat lipflat_lip
Flat spots — very important. Nobody wants a kicky kicker.
m · from 0
05
Takeoff anglelip_angle
Angle at the lip. Derived from H and R, overridable via slider.
° · 50 – 65
03 · ANATOMY

Section

The section.

Your kicker, with your inputs. In section view, always sanity-check visually that the kicker looks right. You can add a landing and a roll-in to see reference heights.

SECTION · K-01
H3.20 m R6.21 m α61.0°
SCALE · 1:50
Section view of a kicker with roll-in and landing. Height 3.20 m, Radius 6.21 m, Lip 61.0°.Roll-in · Hard Pack · μ 0.040H · 3.20 mL · 5.43 mα · 61.0°
04 · FLAGS

Diagnosis

Every code writes you a line.

Engine flags are codes with severity. The model checks what is checkable and names what is unclear.

OK
Geometry consistent. Tangent angle within 30°–65°.
GEOM_OK
Info
Length automatically derived from H and R — override available.
LENGTH_DERIVED
Warn
Roll-in not tall enough — short by about 1.8 m. NO PUSHING, 80 kg rider.
ROLLIN_UNDERSIZED
Error
Height exceeds radius. No tangent angle possible (H ≤ R).
HEIGHT_EXCEEDS_RADIUS
14 · START

Try it out and draw your MTB kicker / jump.

Offline, in the browser. No sign-up, no cookies, no server logs. Inputs stay local; the construct can be exported as JSON.

Open constructor