Magnatraction is the definition used by Scalextric (Hornby) to "market" the use of additional magnetic devices in their vehicles to help give extra traction on the track.
Very simply, it is the use of specific magnets to help hold the car on the steel rails of the track, giving extra downforce, preventing the rear end from skidding sideways. Note that the contact rails must also be made of a magnetic material.
Certain motors also have an inadvertent Magnatraction effect, if the car is low enough to the track and the magnets are open. This effect is very slight with most modern "can" (Mabuchi) type motors but it can be very significant on older open-frame type motors.
Therefore, because all electric powered slot cars will have some form of magnetic downforce produced by the electric motor, the definition of Magnatraction is any type of additional device(s) added to a chassis which produces magnetic downforce to increase grip.
If we advertise a vehicle that includes Magnatraction, then this will have a magnet that is specifically designed for that vehicle.
Further information from Scalextric
The magnet strength is a factor that is designed into the car’s performance. It is not a case of how strong the magnet is (gauss) but the downward force it affords to the track. Therefore, it has been possible for them to set a thinner magnet slightly lower in the chassis but still have the same effect as a thicker magnet set higher in the chassis.
Changing the tyre diameter will affect the magnetic pull against the metal rails or steel track braid. Other factors such as track camber, raised or sunken pick up rails relative to axle height, dust on track and tyres, track surface (wood, paint, plastic etc.) all ‘undo’ the careful design measurements built into their design. Even the strength of two identical physical size magnets will have a variance in gauss strength, as no two magnets can be the same.
The general shape and weight distribution of the vehicle then also affects the cornering and acceleration abilities, meaning that no single standard down force strength is appropriate for any given car.
Not least, the driver’s own skill at the hand-controller varies from person to person and, of course, a driver’s ability will vary from lap to lap. Therein lays the essence of racing.
It is, in the main, the skill of the driver interacting with all of the above conditions which surely makes the hobby of slot racing interesting and compelling. Scalextric tries to achieve a reasonable balance of performance between all cars in the Scalextric range.
Magnatraction as used by Scalextric is a very easy way to give a Scalextric car significantly extra traction on the track. Strong Neodymium magnets can easily overcome poor mechanical grip from the tyres. With this feature the choice is a very personal one.
Magnatraction can be a great feature to speed up racing or it's a curse that reduces racing skill.
