Friction Wheels are used to propel a roller coaster train along a piece of track, they are also referred to as drive tyres or kicker wheels. They are often used in station areas and brake runs, but they can also be used to propel the rollercoaster train up a lift hill.
How do Friction Wheels Work?
Friction Wheels are normally used in one of two ways on roller coasters, either vertically or horizontally. Friction Wheels are also used to power other types of amusement rides, such as Ferris Wheels and Pirate Ships.
When oriented vertically, the drive tyres make contact with a flat area, which often has a grated metal surface on the underside of the roller coaster train as it crosses a particular section of track. The grated metal surface helps to increase friction with the tyres. Junior Roller Coasters often use drive tyres fitted vertically instead of a chain on lift hills. A major disadvantage of using vertical drive tyres is that rainy weather can greatly reduce the friction between the tyre and the train, in order to combat this, rides using this method of propulsion may either be closed in wet weather or the number of riders reduced.
When used horizontally, Friction Wheels are put in pairs so as to “squeeze” a portion of the train as it crosses that section of track. When used in this way, it is usually the brake fin underneath the roller coaster train that the drive tyres squeeze to propel or slow the train forward.
Occasionally large roller coasters also use Friction Wheels fitted horizontally on their lift hills too. These are the ideal choice if the lift hill utilises curved track as it would be very challenging to utilise some of the other methods of propulsion. Magnum Force which was formerly located at Flamingo Land Resort in North Yorkshire was a good example of how these Friction Wheels can be utilised on a curved lift hill.
Friction Wheels are generally used to propel the roller coaster train at speeds between 5-8 mph, but The Incredible Hulk Coaster at Universal’s Islands of Adventure in central Florida is notable for using horizontal drive tyres to launch the roller coaster train up an incline, reaching a speed of 40mph in 2 seconds.