Older E-Bike doesn't assist

CharlesM99

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Hi all, I'm new here but it looks like a great place to learn more about e-bikes!

I bought an older non working E-Bike for next to nothing, just to mess around with and learn more about how these things work. I assumed the only issue was the battery was dead, but I think I'm wrong about that!

The old battery was definitely dead so I built a 7s7p battery with 18650s, which seems fine, but I haven't been able to put it through the pases yet. Because the bike still doesn't work properly but it turns on now, the controller on the handle bar seems to work (LEDs light up and I can adjust the assistance level), the pedal sensor by the cranks blinks red when pedaling but I'm not getting any pedal assistance out of the motor.

Any ideas what I should check next?

The bike has a front hub motor labeled as "Trio", model number bfswxb24v250w185r. I think that is a rebranded Bafang motor? I can spin the motor by hand, but there is some resistance and it comes to a stop pretty quickly.

The controller has two brake sensors going to each brake lever. If those go bad seems like they could prevent the motor from getting power. Seems like I could disconnect them and maybe add a jumper to make sure they aren't causing any issues.

The controller says it expects 1.2-4.4v for the "speed signal input voltage". I'm guessing that is the pedal sensor, so I'll check that out tomorrow.

Any input or advice would be greatly appreciated!

Worst case I'll get a new controller and front hub motor and be done with it!
 
You can test without a throttle. Get a resistor between 5 and 10 Kiloohms. The input should have 3 conections: 5 volts, signal and ground, connect the resistor between 2 lines, one combination (5v and signal) will cause the motor to run, be carefiul it will be full speed. Don't use a bare wire, you will short the power supply.
 
You can test without a throttle. Get a resistor between 5 and 10 Kiloohms. The input should have 3 conections: 5 volts, signal and ground, connect the resistor between 2 lines, one combination (5v and signal) will cause the motor to run, be carefiul it will be full speed. Don't use a bare wire, you will short the power supply.
Ok thanks. I'll see if I can find the right resistor and give that a try.

Otherwise, this evening I'll try adjusting the pedal sensor to see if that helps.
 
Looks like there isn't even a place to wire in a throttle. I guess I can do the same concept with the pedal sensor though.

There are only 6 connectors on the controller:
-Red+black from battery
-Red+black+yellow for pedal sensor
-2x Red+green+black for each brake lever sensor
-Red+green+black+blue for the display/controls
-Yellow+blue+green going to the motor

The controller gets hot, but that motor doesn't want to do anything.

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1000008589.jpg
 
Ive figured out the controller is probably good still.
But the motor is definitely toast! I took it apart and the clutch and gears would barely budge.

Ideally I can get new motor and gear internals and swap them into the existing hub body and rim. But maybe I'm better off to order a whole new hub motor with the rim.
 
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