In the forums, electric motors with damaged surface coatings are often seen. There are relatively many posts where the ST3 is affected, which is probably due to statistics, as it is one of the most popular models in the Stromer model range.
The problem has been ongoing for some time and also affects other models. TDCM, the motor manufacturer, seems to repeatedly have quality issues with the surface coating of the rotor motor.
The problem is further accentuated for year-round riders who are out and about in all weathers and on salted roads in winter. If the bike is not cleaned after every ride, corrosion damage occurs even more frequently. This usually starts at the spoke holes or the parting line that runs through the center of the motor drum.
Some of the damage is probably due to an incorrect washing method with a cleaner that is too harsh.
Stromer expressly recommends not using a high-pressure cleaner, steam jet or garden hose. The latter also has a pressure of up to 6 bar.
See Pimp my Stromer 'Care / cleaning of the Stromer'
See also FAQ – 'Care...'
Newer electric vehicles from 2024 onwards are again featuring motors with powder coating, which TDCM used previously. The new coating is intended to be more resistant to corrosive influences.
Guarantee? Based on feedback, it's worth having the dealer arrange a warranty exchange with Stromer. Stromer is usually accommodating.
No guarantee: If the motor is out of warranty, both a DIY and professional solution are possible. In addition to repainting, professional providers also offer repair of motor bearings, Hall sensors, temperature sensors, motor cables, or re-bonding loose rotor magnets.
See Here too the topic: ENGINE – ‚Repairs'