3-inch and light 4-inch FPV motor
FPVCycle 16mm
A 16 mm-stator motor FPVCycle built for high-powered 3-inch quads and light 4-inch ones: 4100KV, about 13 g, with an M3 titanium prop shaft and a 9 × 9 mm M2 mount.
- 3-inch on 3S–4S (over 150 g)
- light 4-inch on 3S (under about 250 g)
- 9 × 9 mm M2 motor mounts
The spin is an illustration: the model turns at 1/600 of the no-load speed, and it is a generic 16mm motor drawn from FPVCycle’s published sizes, not its exact design. No-load speed is KV × 14.8 V, a nominal pack for this version. FPVCycle publishes no bench data for it.
- Weight
- 13 g
- about 13 g with about 70 mm of lead; about 16 g with the prop adapter, nut and 240 mm of 24 AWG lead
from $17.99a motor at FPVCycle
A set of four: $71.96
Price seen Oct 19, 2026. Plain links: we earn nothing from them.
What you get for $17.99
Wide and tall stator
A 16 mm stator more than 5 mm tall, with more stator volume than a 1605; FPVCycle uses a middling 4100KV to manage heat.
Source: FPVCycle product page
M3 shaft with M5 adapter
A lighter M3 titanium prop shaft with an M5 adapter that unscrews, so it takes M3 or M5 props.
9 × 9 mm M2 mount
M2 screws on a 9 × 9 mm pattern, to fit lighter frames.
Source: FPVCycle product page
N52SH magnets, Kawasaki steel
N52SH arc magnets and 0.15 mm Kawasaki laminations in a 7075-T6 casing.
Source: FPVCycle product page
What to pair it with
Our reading of FPVCycle’s numbers, so your build matches what the motor was tested with.
- Battery
- 3S–4S on 3-inch props for crafts over 150 g; 3S on 4-inch with very low-load props under about 250 g. (FPVCycle product page)
- ESC
- FPVCycle calls the motor powerful and “notchy” and asks for a properly fitted, suitably sized capacitor. (FPVCycle product page)
- Frame
- M2 screws on a 9 × 9 mm pattern; the base is not flush mount. (FPVCycle product page)
Where to buy
Plain links, not affiliate links. Prices change; the store’s page has the current one.
Full specs
| Spec | Value | Source |
|---|---|---|
| KV | 4,100 rpm/V (FPVCycle’s 2021 guide lists it at 3700KV) | FPVCycle product page |
| Stator | 16 mm diameter, more than 5 mm tall | FPVCycle product page |
| Battery | 3S–4S LiPo (3S–4S on 3-inch props, 3S on 4-inch) | FPVCycle product page |
| Weight | 13 g (about 13 g with about 70 mm of lead; about 16 g with the prop adapter, nut and 240 mm of 24 AWG lead) | FPVCycle product page |
| Shaft | M3 grade 5 titanium prop shaft with an M5 adapter; 3 mm grade 5 titanium internal shaft | FPVCycle product page |
| Mounting | M2 screws on a 9 × 9 mm pattern (not flush mount) | FPVCycle product page |
| Bell | 7075-T6 aluminium, one-piece (UniBell) | FPVCycle product page |
| Magnets | N52SH arc magnets | FPVCycle product page |
| Bearings | Japan ISC custom 520ZZ, 2 × 5 × 2.5 mm | FPVCycle product page |
| Winding | Single-wrap oxygen-free copper, 260 °C enamel | FPVCycle product page |
| Leads | 24 AWG (FPVCycle weighs it with 240 mm leads) | FPVCycle product page |
Inside the motor
A brushless outrunner: the coils stand still in the middle and the magnets spin around them. From the top down:
- Bell. 7075-T6 aluminium, one piece. (FPVCycle product page)
- Shaft. 3 mm grade 5 titanium internal shaft; M3 titanium prop shaft with an M5 adapter. (FPVCycle product page)
- Magnets. N52SH arc magnets. (FPVCycle product page)
- Stator. 16 mm, more than 5 mm tall, 0.15 mm Kawasaki laminations, single-wrap oxygen-free copper. (FPVCycle product page)
- Bearings. Japan ISC custom 520ZZ, 2 × 5 × 2.5 mm. (FPVCycle product page)
How fast it spins
KV is the motor’s no-load speed per volt. With nothing on the shaft, the 4100KV version reaches about these speeds; a prop loads the motor and brings it down, typically to around 70–75% of these figures at full throttle.
| Battery | Volts | No-load rpm (KV × V) | Electrical frequency | ESC steps per second |
|---|---|---|---|---|
| 4S nominal | 14.8 | 60,680 | 7,079 Hz | 42,476 |
| 4S full | 16.8 | 68,880 | 8,036 Hz | 48,216 |
| 6S nominal | 22.2 | 91,020 | 10,619 Hz | 63,714 |
| 6S full | 25.2 | 103,320 | 12,054 Hz | 72,324 |
A 14-pole rotor has 7 pole pairs, so every turn of the shaft is 7 electrical cycles, and a six-step ESC switches the phases 42 times per turn.
About the 3D model
A generic outrunner drawn from FPVCycle’s published sizes: the 16mm stator, 3 mm shaft and 9 mm mounting circle. Anything FPVCycle doesn’t publish is typical for a motor this size, and the bell’s spoked top, the base and the inside are a generic design, not this motor’s. The colours are read off the maker’s product photos. There are no logos or markings: it is our drawing, not the maker’s.