Ask Miles, our Setup AI that’s been trained on the Medius X20FWD '21.
Setups
Gearing
Stock gearing for the Serpent Medius X20FWD '21, with common pinions and their ratios.
| Pinion | Spur ÷ pinion | FDR |
|---|---|---|
| 36T | 2.17 | 3.92 |
| 37T | 2.11 | 3.82 |
| 38T | 2.05 | 3.72 |
| 39T | 2.00 | 3.62 |
| 40T | 1.95 | 3.53 |
| 41T | 1.90 | 3.44 |
| 42T | 1.86 | 3.36 |
| 43T | 1.81 | 3.28 |
| 44T | 1.77 | 3.21 |
| 45T | 1.73 | 3.14 |
| 46T | 1.70 | 3.07 |
| 47T | 1.66 | 3.00 |
Shaded rows are the pinions most 1/10 FWD touring/gt 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 Medius X20FWD '21, with the range racers in the class run.
Get a recommendation →Shop pinion gears at AMain → (opens in new tab)What pinion gear should I use on the Serpent Medius X20FWD '21?
It depends on your motor and the track. In the 1/10 FWD touring/gt class, racers gear by final drive ratio: 17.5T near 4.51. On the Medius X20FWD '21's stock 78T spur that is about 31T for 17.5T. Tight tracks gear down, open tracks gear up. For a starting pinion matched to your motor, use the So Dialed Pinion Recommender with the Medius X20FWD '21 selected.
What is the internal ratio (transmission ratio) of the Serpent Medius X20FWD '21?
The Medius X20FWD '21 has an internal ratio of 1.81:1. Final drive ratio = spur ÷ pinion × 1.81. With the stock 78T spur, a 36T pinion gives an FDR of 3.92 and a 47T gives 3.00.
How many teeth is the stock spur gear on the Serpent Medius X20FWD '21?
78 teeth. Changing the spur moves every pinion's ratio at once; most racers leave the spur and tune with the pinion.
Kit setup
Kit shock setup (Medium grip). Part numbers link to AMain.
- Front
- 400 cst
- Rear
- 400 cst
- Front
- 200,000 cst
What shock oil does the Serpent Medius X20FWD '21 come with?
Out of the box the Medius X20FWD '21 runs 400 cst front, 400 cst rear (Serpent oil), on 4 hole (#401841) front, 4 hole (#401841) rear pistons. That is the kit setup; you will need to adjust it for your track conditions. The RC Setup App can help dial it in.
What springs does the Serpent Medius X20FWD '21 come with?
The kit springs are Yellow 2.6 (#401853) front, Yellow 2.6 (#401853) rear. Stiffer springs suit high grip and big jumps; softer springs add grip on slick or bumpy tracks.
What diff fluid does the Serpent Medius X20FWD '21 come with?
The kit diff fluid is 200,000 cst front. Thicker front adds steering on power; thicker center sends more drive rearward; thicker rear stabilizes the car under throttle.
Setup Help
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RC Setup App
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