For many e-bike riders, “motor noise” is more than just a minor annoyance — it’s a disruption to the serenity of morning commutes or weekend rides through quiet neighborhoods and parks. The culprit lies in poor NVH control — Noise, Vibration, and Harshness.
To address this, PREETO has engineered a complete NVH solution, refining everything from gears to materials to housing design. The result: a noise level of below 55 dB at one meter — as quiet as a normal conversation — delivering a ride that’s both powerful and peaceful.
Gear Design: Precision that Tames the Sound
At the heart of noise reduction lies the gear system.
Both the primary and secondary gear stages use helical gears with a meticulously calculated helix angle of 20° ± 1°, transforming the contact pattern from a “line” into a broader surface engagement.
This increases the contact area by 40% and reduces impact noise by 15 dB.
Each gear undergoes crown modification to eliminate micro surface errors within 0.005 mm, preventing “sticking noise” during meshing.
According to the Klingelnberg Gear Measurement Center, PREETO’s optimized gears achieve a meshing deviation of less than 0.003 mm, resulting in an additional 8 dB noise reduction.
The outcome? During riding, all you hear is the subtle roll of the tires against the pavement.
Materials: Absorbing Vibrations at the Source
Noise control continues with smart material engineering.
The first-stage gear is made of lightweight polymer material, which absorbs up to 30% of vibration energy compared to metal gears — minimizing metallic impact sounds.
When riding over speed bumps or uneven roads, these polymer gears dampen shock-induced vibration, preventing resonance amplification.
The motor housing, built from recyclable aluminum alloy, acts as a natural vibration damper, reducing electromagnetic noise transmission to the environment.
The surface features micro-textured patterns that scatter sound waves to avoid reflection hotspots.
Inside the transmission casing, a 0.5 mm acoustic foam layer absorbs high-frequency noise above 2000 Hz, further lowering tonal harshness.
Structural Optimization: Reducing Noise Layer by Layer
PREETO’s three-stage parallel transmission significantly cuts noise compared to traditional planetary gear systems.
With four fewer gears than comparable planetary drives, noise stacking is reduced by about 10 dB.
The rotor-stator design adopts asymmetric slot geometry, disrupting electromagnetic harmonics and eliminating the characteristic “whirring” sounds above 1000 Hz.
Between the bearing and housing, rubber damping pads isolate mechanical vibration from the frame.
Even at 750 W peak power output, PREETO motors maintain sub-55 dB operation — ideal for early-morning rides, late-night commutes, and noise-sensitive environments.
Quiet Power Meets Real-World Comfort
PREETO’s NVH optimization isn’t just about engineering precision — it’s about enhancing the emotional experience of riding.
When silence replaces mechanical hum, the rider becomes more attuned to the rhythm of motion — the wind, the road, the landscape.
It’s the fusion of power and peace, precision and comfort, that makes every ride not only efficient but enjoyable.
Certifications & Sustainability
All PREETO motors are developed and produced under ISO 9001 and ISO 14001 quality and environmental systems.
They meet international safety and performance standards including EN15194, CE, and TÜV certifications.
The use of recyclable aluminum and high-efficiency design (up to 93% energy conversion) reflects PREETO’s commitment to sustainable mobility.
Behind PREETO’s whisper-quiet ride lies a symphony of precision — every gear, material, and structure tuned to perfection. By combining automotive-grade NVH engineering with e-bike innovation, PREETO is redefining what “quiet power” truly means — a motor that delivers strength in silence.
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