The TSRF24 and TSRF32 cars are supplied with the same gear ratio for each scale, representing the optimum set up for their size, weight and use. However and in certain circumstances, it may be necessary to change the gear ratios to get the maximum performance from the cars.

In each case, the criteria are the following: if the car reaches its top speed very quickly on a very long straight, the car may need to be geared with a taller ratio, meaning a larger pinion with a smaller spur gear.

If the car fails to reach its top speed quickly and appears to be sluggish at normal operating voltage, it may be necessary to install a shorter ratio.

In any case, the TSRF chassis requires a change of both the motor pinion and the spur gear, just like a full-size racing car.

To proceed, you will need a quality pinion puller such as a Hudy or similar. TSRF with soon offer its own pinion puller in our tool line.

Once the pinion is removed, the new pinion needs to be pressed in place and this can be accomplished in a precision machine vise or a pinion press The motor shaft may be trimmed with a Dremel disk and chamfered prior to installation, so as to facilitate pressing.

The Home-Racing cars come with a steel pinion and a glass-filled Nylon spur gear, both in 64-pitch. You may use the available Nylon pinions (part number T2405 for the 11-T and T3205 for the 14-T) as press-on, perfectly adequate for home-racing use. We recommend to clean the motor shaft with a degreaser, place a tiny droplet of synthetic motor oil in the bearing, place a tiny droplet of red Loctite inside the pinion's hole and gently push in place while placing a U-collar spacer made of adequately thick cardboard to retain the pinion from bottoming on the motor bearing. You must leave a clearance of 1.5mm between the bearing and the pinion.

We like the plastic spur gears (part T2404 for the 45-T, T3204 for the 48-T), and again red Loctite may be used to affix them permanently on the rear axle. The Club-Racing spare gear ratios are supplied with a metal pinion and a setscrew spur gear. This gear has exactly the same width as the Nylon units and requires the use of a .035" hex wrench. A small flat may be ground on the axle but it has been shown that this is really not necessary.

TSRF offers 4 different gear ratios. The car are fitted with the following from the works:

TSRF24 kits and RTR: 11/48

TSRF32 kits and RTR: 14/45

Other ratios available: 12/47 and 13/46.

If using the metal gears, combinations of 12/48, 13/47 and 14/46 may be used. Some breaking-in time may be necessary.