Gear Ratios

There are several gear ratios across the standard range of Scalextric cars. The two most common ratios are 3:1 and 3.2:1. The standard gear ratio configurations are: in-line motor (27/9 tooth) 3 : 1 sidewinder motor (36/11 tooth) 3.2 : 1

The gear on the motor is called the pinion gear. The gear on a side winder axle is called the spur gear. The gear on an in-line axle is called a crown or contrate gear.

Ratios can be changed to alter the performance of a car. Alternative pinions from The Performance Parts range can be used to change the gear ratio with the aim of fine tuning the performance of a car to the circuit layout.

The easy way to get started and see results:

 Scalextric offers packs of pinion gears - C8402 or C8403. These contain 5 pairs of 8 to 12 tooth pinions. The rule of thumb is: the fewer teeth on the pinion gear the quicker the acceleration and better the braking - but a lower top speed.

Try each pinion and record your lap times for each. You’ll soon find that there are many variables to consider – the length of straights, torque of the motor, grip of the tyres, radius of curves, ohms rating of hand controllers, driver technique, rpm of motor, braking ability of motor, size of crown or spur gear on axle, radius of tyres, strength of magnet. Choosing the correct pinion for your car is a matter of trial and error.

Changing one thing at a time and retesting is the best way of tuning your car.

Gear Ratios for Sport+ Gears

With Thanks to Bob Schleicher, modelcarracingmag.com

The gear ratios on the chart are the ideal mesh between the pinion and crown or spur gear. On cars with inline motors the separate collar with blue insert controls the gear mesh so you can obtain  an acceptable mesh with a crown gear with one more or one less tooth than “ideal”. The standard Scalextric gear ratio for inline “SP” motored cars is 3.000:1 (a 9-tooth pinion and 27-tooth crown gear). The ideal gear mesh allows the rear axle move about .005-inches (the thickness of regular paper) from side to side AND the axle should be able to rotate back and forth about twice that tiny distance without any pinion gear movement.

There is no way to adjust the gear mesh with sidewinder motors because the distance between the rear axle and motor shaft is fixed. Cars with sidewinder motors should only be geared with combinations shown which should produce the “ideal” gear mesh if you adjust the rear wheels in or out allow only the .005-inches of side-side rear axle movement. The standard Scalextric gear ratio for sidewinder chassis with “SP” motor is 3.270:1 (an 11-tooth pinion and a 36-tooth spur gear) but the 11/35 set of gears (3.182:1) should offer comparable performance to the standard Scalextric sidewinder gearing.

With Thanks to Bob Schleicher, modelcarracingmag.com