Rocker

(Hans Gijsen 2009 - now) An illustrated explanation of the rocker in speedskates. For a mathematical approach see page Rocker maths.
The goal is to minimize ice friction and optimize steering and efficiency.
Doing so, the rocker choosen determines the behavior of the skate in the bend. By bending the skate afterwards we can optimize that behavior leaving the rocker as it is.

Shown is a scaled model 1:100 of a circle 42 meters high.
The scaled model is 42cm. A 4mm small part at the edge represents a skate.

In reality a circle of 42m.

Of which the skate is a piece of 40cm at the circumference.



A lightbulb straight above the model throws its shadow on the table. That shadow resembles the bend our skate wil follow under different angles of the circle. The shadow is a straight line with the model perpendicular on the table. The skate goes straight ahead.

With the model under a certain angle to the table, its shadow straight under the tiny skate segment shows the circular bend the skate wil follow. These images illustrate the equations given on page Rocker maths.

Only at last, with the circle flat on the table, the circular bend the skate wil make is the same as the circumference of the circle. Its shadow also. In reality the skate wouldn't have grip anymore in this extreme.