Motors · Shimano
Shimano · STEPS E8000 (DU-E8000)

STEPS E8000

Shimano's first proper eMTB flagship, launched in 2016 to take the fight to Bosch. Compact, torque-sensing and tuned for a natural pedal feel rather than raw shove. Now superseded by EP8/EP801, but still a benchmark for how a mid-drive should read your input.

STEPS E8000 eMTB motor
The compact DU-E8000 drive unit with its standard Q-factor crankset (Photo: Velomotion / Irmo Keizer).
0250500406080100120500 Wcadence (rpm) →power (W)

Schematic illustration (not bench-plotted data): a narrow-band curve that builds to a peak around 70-90rpm then drops away steeply on either side, with very little assistance below 50 or above 105rpm. No independent dyno power-vs-cadence trace exists for this motor, so the shape reflects Shimano's published behaviour and rider reports rather than measured watts.

The verdict

Shimano STEPS E8000 was the motor that made Shimano a serious eMTB player. Rated at 70Nm and 250W nominal, with around 500W on tap at peak (a figure widely cited by reviewers rather than an independently dyno-verified number), it never had the headline torque of later units, but it earned its reputation on delivery rather than numbers. The control is torque-based, not cadence-triggered, so how much you pedal directly governs how much it gives back. The result is one of the most natural, predictable mid-drives of its generation.

Power is happiest in a tight cadence band of roughly 70-90rpm, where it feels eager and linear. Drop below 50rpm or spin past 105rpm and assistance falls away sharply, so it rewards a tidy, rhythmic pedalling style on climbs. The compact casing kept the Q-factor close to a normal chainset and allowed shorter chainstays than rivals of the day, which is a big part of why E8000 bikes still ride so cleanly. Cooling fins help it hold output on sustained climbs.

Its weaknesses are honest ones for a 2016 design: it is audibly louder under load than the EP8 that replaced it, it carries the classic STEPS coast-clutch click on rough ground, and peak torque is now well behind modern 85-120Nm units. But for smoothness, a listed 2.88kg weight and that uncannily intuitive power feed, the E8000 still holds up. It is a connoisseur's motor, not a chest-thumper.

“Smoothness and packaging over outright torque - the E8000 gives back almost exactly what you put in.”

Sustained power & heat

How long the headline number actually lasts under sustained climbing load.

504 Wh (BT-E8035)

No published independent thermal de-rate data; cooling fins designed to maintain output on extended ascents.

Character

Rider input
Shimano publishes a 300% maximum assist ratio in Boost. Because delivery is torque-sensed, you must keep pedalling firmly within the 70-90rpm band to access full output; Trail and Eco modes scale the support down for range.
On the trail
Intuitive and beautifully linear - assistance tracks your effort almost instantly, giving precise, confidence-inspiring control on technical climbs rather than the all-or-nothing shove of some rivals.
Noise
No reviewer published an A-weighted dBA figure for the E8000, so there is no measured noise number to quote. In direct back-to-back use it is consistently described as noticeably louder under load than the EP8 that replaced it, with a distinct coast-clutch click on rough terrain; Brose units of the era were the clear quiet benchmark. Frame and cable routing strongly affect how much of it reaches the rider.
Efficiency
Smooth, well-modulated power feed makes it easy to ride economically; the torque-based control wastes little energy on overrun, helping real-world range despite the modest 250W nominal rating.

The case for and against

Strengths

  • Exceptionally natural, torque-sensed power delivery
  • Light for its era at a listed 2.88kg
  • Compact casing allows short chainstays and standard Q-factor
  • Cooling fins help hold output on long climbs
  • Tunable assist character via E-TUBE custom modes

Compromises

  • Audibly louder under load than the later EP8
  • Coast-clutch click on rough ground
  • 70Nm now well behind modern high-torque motors
  • Assistance drops off sharply outside 70-90rpm

How it stacks up

No outlet has published a like-for-like measured peak-power-at-fixed-input dyno comparison for these motors, so the ranking below is by torque rating and consistent rider/test impressions rather than lab watts. On torque the E8000's 70Nm sits below the Bosch Performance CX of its day (75Nm then, 85Nm later) and well under the EP8 that replaced it (85Nm) and modern 85-120Nm units from Bosch, Specialized and DJI Avinox. Where it wins is feel and packaging: it is smoother and more natural than the period Bosch CX and lighter at a listed 2.88kg (vs ~2.9kg for the CX Gen2 and ~2.9kg for early Brose Drive S), while Brose's belt-drive units were the quieter, creamier benchmark. The E8000's edge was always delivery and a compact, short-chainstay-friendly casing, not outright muscle.
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