Ohiopicker

My wife just bought a Hyper City Bike (the blue one) that appears to have been ridden once or twice. The PAS operates fine in the top two ranges, but generally does not work in low, or works very intermittently (enough so that it threw me off the bike while turning around!) any ideas where to start? Thanks in advance.

Freerojo

This may or may not explain the issue, bear with me. On the Bafang mid drive we have the option of selecting (in programming) how far the cranks turn before the motor starts to kick in. I am assuming that once you are up to speed you are pedaling normally so the motor is always on. It sounds like when you are starting out you may be cranking almost a revolution and slowly before the motor gets the message and it is taking you by surprise. Can you contact support for that bike?

Freerojo

I just found this from a review of those bikes : “The power assist does not come on immediately after you start pedaling. The Assist kick in after you complete two or three pedal cycles. This will work perfectly with a flat surface when you ride in the city.”

https://mashtips.com/review-hyper-e-ride-city-ebike/

Ohiopicker

To further clarify, this is the least expensive Hyper City, not the one with mid-drive. The low level of pedal assist opates either sporadically or not at all. The other levels work fine. I still need help with this.

Doc_Wui

I learned to squeeze the brake levers lightly to inhibit power for low speed maneuvers on any ebike. Originally, I would shut off the bike completely on my first one. Since this is a Walmart bike, are you still in the free return period? Try another one?

If you have a two piece pedal sensor, with a separate magnet spaced away from a sensor make sure the magnet ring hasn't moved away from the sensor, I had this happen last Winter, got power on only half the pedal stroke as the ring wobbled on the pedals.

Ohiopicker

Doc Wui - thank you for this information. I will look at the cadence sensor mechanism in more detail.