Ask Miles, our Setup AI that’s been trained on the MRX Master Edition.
Setups
Gearing
Stock gearing for the Atomic MRX Master Edition, with common pinions and their ratios.
| Pinion | Spur ÷ pinion | FDR |
|---|---|---|
| 6T | 8.67 | 8.67 |
| 7T | 7.43 | 7.43 |
| 8T | 6.50 | 6.50 |
| 9T | 5.78 | 5.78 |
| 10T | 5.20 | 5.20 |
| 11T | 4.73 | 4.73 |
| 12T | 4.33 | 4.33 |
| 13T | 4.00 | 4.00 |
| 14T | 3.71 | 3.71 |
What pinion should I run?
Tell us your motor and track and get a starting pinion for the Atomic MRX Master Edition, with the range racers in the class run.
Get a recommendation →Shop pinion gears at AMain →What pinion gear should I use on the Atomic MRX Master Edition?
It depends on your motor and the track. A hotter motor (lower turns, higher Kv) takes a smaller pinion; a tight track wants a lower gear than an open one. Start near the middle of the pinions the MRX Master Edition shipped with, run a few minutes, and check motor temperature before going up a tooth. The So Dialed Pinion Recommender gives a starting pinion for your motor where we have class data.
What is the internal ratio (transmission ratio) of the Atomic MRX Master Edition?
The MRX Master Edition has an internal ratio of 1:1. Final drive ratio = spur ÷ pinion × 1. With the stock 52T spur, a 6T pinion gives an FDR of 8.67 and a 14T gives 3.71.
How many teeth is the stock spur gear on the Atomic MRX Master Edition?
52 teeth. Changing the spur moves every pinion's ratio at once; most racers leave the spur and tune with the pinion.
Setup Help
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