E-P3+ MX
Polini's E-P3+ MX is Italy's quiet outsider in the full-power eMTB motor wars: a claimed 90 Nm and 600 W peak from a compact 2.95 kg, fully user-serviceable mid-drive built by an 80-year-old small-engine specialist — with a 2026 EVO2 limited series pushing the MX variant to a claimed 105 Nm.
Polini E-P3+ MX is the motor most riders have never thrown a leg over, and that is the forum's running theme rather than a knock on the hardware. Polini Motori — long famous for two-stroke tuning kits — claims 90 Nm and a 600 W peak from a 2.95 kg unit, which on paper lines it up against the Brose Drive S Mag (90 Nm / 560 W) and the older Bosch Performance CX rather than today's headliners like the Bosch CX Gen 5 (120 Nm / 750 W post-PU2.0) or the DJI Avinox M2S (150 Nm / 1,500 W). It runs on Polini's 36 V ecosystem battery, though Polini does not publish a motor-voltage spec, and quotes peak torque only — there is no rated/continuous torque figure.
On the trail the character is smooth and progressive rather than punchy: power builds gradually as you load the pedals, which makes for composed traction on greasy starts and technical step-ups but lacks the instant shove of a Bosch CX or DJI Avinox. Output is shaped through named maps — Touring, Dynamic and Race presets plus two fully custom profiles, each with five assist steps — and Polini publishes no single max-assistance ratio, so the configurability lives in those maps rather than one headline percentage. The standout is openness: you can flash firmware and tweak maps yourself over a cable, and the motor is genuinely disassemblable. That hackability extends to the aftermarket SpeedFun Furious Evo derestriction kit, a plug-and-go device that lifts the 25 km/h limit (race use only) without physical modification.
The compromises are noise and reach. Independent testing (MountainBiker.es) calls the motor "somewhat louder than desired" and pins the precision-machined whine on its all-metal internals — there is no plastic inside — rather than on any specific rival comparison. And with adoption limited largely to Italian and a handful of European OEM partners, service lives or dies by the Polini dealer network, although the 2026 EVO2 limited series (max 3,000 numbered units) adds redesigned casings, USB-C diagnostics and a three-year warranty. No independent dyno test has been published, so every figure here is a manufacturer claim and the power curve is representative, not measured.
Character
The case for and against
Strengths
- Strong claimed 90 Nm / 600 W from a compact 2.95 kg unit (EVO2 2026 MX claims 105 Nm)
- Frugal battery use reported on long climbs
- Five-map custom tuning, user-flashable firmware and SpeedFun derestriction support
- Genuinely user-serviceable, fully disassemblable all-metal design
- Smooth, controllable delivery on technical terrain; 3-year warranty on EVO2 series
Compromises
- Precision-machined whine — "somewhat louder than desired" in testing, no measured dBA
- No independent dyno data — figures are manufacturer claims, curve is representative only
- Niche adoption, service tied to the Polini dealer network
- Trails Bosch CX Gen 5 (120 Nm) and Avinox M2S (150 Nm) on outright torque/peak power
