That same evening, on 19 August, I contacted Amflow's support service, where I described the problem in great detail, including photos. They responded fairly quickly:
Thank you for contacting Amflow Customer Support. We are grateful to assist you with your concern.
We understand your situation. Normally, there will be three main causes of the speed sensor error:
- The connection problem. Sometimes, reconnecting the cable from the motor will be helpful.
- The rear wheel got loose or the thru-axle is loose. The solution will be to remount the rear wheel.
- The sensor is damaged or the surface of the sensor got covered with mud. If cleaning the surface of the sensor does not help, it is possible that the sensor is faulty.
Based on your description, this is very likely the second possibility. We recommend you remove the rear wheel to inspect the surface of the speed sensor and the grid plate, then reassemble the rear wheel. For the thru-axle, the standard torque value is 10N·m. Please let us know any further updates.
Additionally, we would like to know if you ordered the bicycle from local resellers or the official site of Amflow.
After that, I went to the local service center where I gave them this email with a request to do everything as written here. The mechanics did everything as instructed and returned my bike to me. I rode off and after 4 kilometres, the motor power dropped sharply, and the same errors appeared.
On August 21, I wrote back to Amflow Support to say that the mechanic at the service center did everything you asked and unfortunately the problem is not resolved. I received a reply from Amflow Support on August 22:
Thank you very much for your cooperation.
Based on your feedback, we believe it is most likely an issue with the wheel speed sensor. We would be happy to send you a replacement; however, we are sorry to inform you that our European warehouse is currently out of stock and the next shipment is expected in mid-September. If you need a faster solution, we recommend contacting your local store to have the wheel speed sensor replaced.
I contacted the authorized dealer where I bought my bike and they told me that they don't have this Wheel speed sensor in stock and they don't know when it will be available!!!!
I found this part at one of the authorized dealers and bought it with my own money as it is not that expensive and I didn't want to waste time. I received the part on August 25th and on August 27th the mechanics of the store where I bought the bike installed it for me. Immediately after installation I did a little test drive and everything was ok.
But the next day on August 28, the problem came back and the same thing happened:
The display showed the error "Bike power motor restricted," and the DJI app notified me with a "speed sensor error." At the same time, the speed reading on the display started showing random, fluctuating numbers.
How can you help and how will you solve this problem?