Ask Miles, our Setup AI that’s been trained on the Slash UMP-Style Modified.
Setups
Gearing
Stock gearing for the Traxxas Slash UMP-Style Modified, with common pinions and their ratios.
| Pinion | Spur ÷ pinion | FDR |
|---|---|---|
| 15T | 5.73 | 15.59 |
| 16T | 5.38 | 14.62 |
| 17T | 5.06 | 13.76 |
| 18T | 4.78 | 13.00 |
| 19T | 4.53 | 12.31 |
| 20T | 4.30 | 11.70 |
| 21T | 4.10 | 11.14 |
| 22T | 3.91 | 10.63 |
| 23T | 3.74 | 10.17 |
| 24T | 3.58 | 9.75 |
| 25T | 3.44 | 9.36 |
| 26T | 3.31 | 9.00 |
| 27T | 3.19 | 8.66 |
| 28T | 3.07 | 8.35 |
| 29T | 2.97 | 8.07 |
| 30T | 2.87 | 7.80 |
| 31T | 2.77 | 7.55 |
| 32T | 2.69 | 7.31 |
| 33T | 2.61 | 7.09 |
| 34T | 2.53 | 6.88 |
| 35T | 2.46 | 6.68 |
What pinion should I run?
Tell us your motor and track and get a starting pinion for the Traxxas Slash UMP-Style Modified, with the range racers in the class run.
Get a recommendation →Shop pinion gears at AMain →What pinion gear should I use on the Traxxas Slash UMP-Style Modified?
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 Slash UMP-Style Modified 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 Traxxas Slash UMP-Style Modified?
The Slash UMP-Style Modified has an internal ratio of 2.72:1. Final drive ratio = spur ÷ pinion × 2.72. With the stock 86T spur, a 15T pinion gives an FDR of 15.59 and a 35T gives 6.68.
How many teeth is the stock spur gear on the Traxxas Slash UMP-Style Modified?
86 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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