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Tools

Quick calculators for the pit table

Final drive ratio
Spur ÷ pinion × the transmission's internal ratio.

7.8:1

Final drive ratio

Spur / pinion
The gear ratio on its own, without the internal ratio.

3:1

Gear ratio

Tyre rollout
Distance the car travels per motor revolution.

Leave blank for plain circumference.

201.06mm

Tyre circumference — add a final drive ratio for true rollout

Don't know your ratio? Work it out from your spur and pinion.

Shock oil
Weight and centistokes, on the chart for the oil in your hand.

The chart most kit manuals and forum posts quote. The safe guess when you are not sure.

350cSt

Losi / TLR

Unit converter
Millimetres to inches, grams to ounces.

1in

What these numbers mean

Each calculator has a page explaining the formula behind it, with reference tables.