14T pinion, 57T spur
A 14T pinion on a 57T spur is a 4.071:1 spur ratio. With an assumed 2.85:1 internal ratio that is a 11.6:1 final drive, which on a 3200KV motor at 2S with 5.5 in tires works out to about 33.4 mph theoretical and 28.4 mph realistic.
5-Pack Steel Metal 32P 5mm Pinion Motor Gear Sets 13T 14T 15T
- 1/8
Pinion sets in 0.8 mod, the pitch this 57T spur uses. Buying a set lets you step one tooth at a time instead of guessing.
$12.99 listed price, changes often
Check price on AmazonWhat final drive does 14/57 give?
The spur ratio is 57 / 14 = 4.071. Your car's transmission or differentials multiply it. The internal ratio varies by model, so here is the final drive across the common range; find yours in the manual next to the gearing chart.
| Internal ratio | Final drive (FDR) | Character |
|---|---|---|
| 2:1 | 8.14:1 | typical 1/10 basher range |
| 2.5:1 | 10.18:1 | typical 1/10 basher range |
| 2.72:1 | 11.07:1 | typical 1/10 basher range |
| 3:1 | 12.21:1 | typical 1/10 basher range |
| 3.5:1 | 14.25:1 | short: torque, cooler |
How fast is 14/57?
Example: a 1/10 4x4 monster truck on 3S, 3200KV motor, 5.5 in tires and an assumed 2.85:1 internal ratio (FDR 11.6:1). Theoretical speed is a no-load ceiling; the realistic figure assumes about 85 percent of it, which is typical on stock tires. For your own motor and tires, use the gear ratio and top speed calculator.
| Battery | Motor RPM | Theoretical | Realistic |
|---|---|---|---|
| 2S LiPo (7.4 V) | 23,680 | 33.4 mph | 28.4 mph |
| 3S LiPo (11.1 V) | 35,520 | 50.1 mph | 42.6 mph |
What does one tooth up or down do?
Speed scales with the pinion on a fixed spur. The heat rating compares each option with 14T, assuming 14T runs at a sensible temperature today.
| Swap | Speed change | Motor heat |
|---|---|---|
| 14T to 13T | -7.1% | cooler |
| 14T to 15T | +7.1% | moderate |
| 14T to 16T | +14.3% | high |
| 14T to 17T | +21.4% | high |
Which cars use a 57T 0.8 mod spur?
The 57T spur on this page is an Arrma HD 0.8 mod spur used on Arrma 1/10 4x4 3S BLX trucks. Pitch matters more than tooth count: 0.8 mod gears only mesh with 0.8 mod gears. Set the mesh with a strip of paper between the gears as you tighten the motor, then remove it; there should be a tiny amount of play. See how to change a pinion gear.
14T on other spurs
Every pinion on the 57T spur
- 13T / 57T: 4.38:1
- 15T / 57T: 3.80:1
- 16T / 57T: 3.56:1
- 17T / 57T: 3.35:1
- 18T / 57T: 3.17:1
- 19T / 57T: 3.00:1
- 20T / 57T: 2.85:1
- 21T / 57T: 2.71:1
Gears and a thermometer for this swap
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Frequently asked questions
What is the gear ratio of 14/57?
57 divided by 14 is 4.071, so the spur ratio is 4.07:1. The final drive ratio multiplies that by your car's internal transmission or differential ratio, which is printed in the manual. At a 2.72:1 internal ratio it is 11.07:1; at 3:1 it is 12.21:1. Use the calculator with your own internal ratio for an exact figure.
Is 14T faster than 13T on a 57T spur?
Yes. On the same spur, speed scales with pinion teeth, so 14T is about 7.7 percent faster than 13T at the same motor RPM. The motor also works harder at every speed, so it runs warmer. Check the temperature after two or three minutes of running before going up another tooth.
Will a 14T 0.8 mod pinion fit my car?
Only if the spur is also 0.8 mod and the motor mount has enough adjustment for the pinion size. Pitch must match exactly; 0.8 mod gears will not mesh correctly with other pitches. Bore size must match the motor shaft, commonly 3.175 mm (1/8 in) on 1/10 motors and 5 mm on larger motors. The spur here is an Arrma HD 0.8 mod spur used on Arrma 1/10 4x4 3S BLX trucks.
RCCarCalc is researched guidance, not professional advice. Figures come from published manufacturer specifications, listings and verified owner reports, not hands-on testing. Speeds are theoretical or as listed; real results depend on gearing, battery, tires and terrain. See how we research.