Wheel Racer

A brown and black exhibit table with matching information panel at the back. On the table is a D shaped rail with wheels sitting on the track.
A brown and black exhibit table with matching information panel at the back. On the table is a D shaped rail with wheels sitting on the track.

The shape of wheels determines how well they follow different shaped tracks.

How it works

Roll sets of tapered wheels along a track to demonstrate how train wheels roll along train tracks.

Things to try or ask around the exhibit

  • How are the wheels shaped differently?
  • Can all wheel shapes roll down the straight track?
  • Which wheel shape moves best around the bend in the curved track?

Background

Some of the wheels are tapered in shape, from narrow to wide like flattened cones. This allows them to move through bends on a track. The narrow wheel rim turns more quickly and over a shorter distance than the wide wheel rim. This allows the narrow rim to move around the inside of tight bends better than the wide rim.

Finding the science in your world

You may have noticed that train wheels are shaped differently to wheels on other vehicles. This is because trains can only move along a raised track, so any curves in the train track must be compensated by the train's wheel shape. As a train's tapered wheels adjust to a curving train track, passengers can feel the train 'sway'.