Ask Miles, our Setup AI that’s been trained on the SRX8e Gen4.
Stock gearing for the Serpent SRX8e Gen4, with common pinions and their ratios.
| Pinion | Spur ÷ pinion | FDR |
|---|---|---|
| 12T | 3.83 | 12.98 |
| 13T | 3.54 | 11.98 |
| 14T | 3.29 | 11.12 |
| 15T | 3.07 | 10.38 |
| 16T | 2.88 | 9.73 |
| 17T | 2.71 | 9.16 |
| 18T | 2.56 | 8.65 |
| 19T | 2.42 | 8.20 |
Shaded rows are the pinions most 1/8 4WD buggy setups run on the stock spur.
What pinion should I run?
Tell us your motor and track and get a starting pinion for the Serpent SRX8e Gen4, with the range racers in the class run.
Get a recommendation →Shop pinion gears at AMain → (opens in new tab)It depends on your motor and the track. In the 1/8 4WD buggy class, racers gear by final drive ratio: 1800–2300 Kv near 10.06. On the SRX8e Gen4's stock 46T spur that is about 15T for 1800–2300 Kv. Tight tracks gear down, open tracks gear up. For a starting pinion matched to your motor, use the So Dialed Pinion Recommender with the SRX8e Gen4 selected.
The SRX8e Gen4 has an internal ratio of 3.385:1. Final drive ratio = spur ÷ pinion × 3.385. With the stock 46T spur, a 12T pinion gives an FDR of 12.98 and a 19T gives 8.20.
46 teeth. Changing the spur moves every pinion's ratio at once; most racers leave the spur and tune with the pinion.
Kit shock setup (Manual). Part numbers link to AMain.
The kit springs are 4.9lb Pink (#600856) front, 3.8lb Purple (#600865) rear. Stiffer springs suit high grip and big jumps; softer springs add grip on slick or bumpy tracks.
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