PAS Problems with Bafang Rear Hub-Drive Kit

[jfny1978]

I got a 500W Bafang Rear Hub-Drive kit recently, and it's mostly been working well.

The chain ring was wobbly, and I got some advice at my local bike shop today about how to reinstall the bottom bracket and I got that rock solid.

When I put it back together though, the PAS was no longer working. I may have tightened it too much, I may have fried it by spraying it with degreaser, or it may have just somehow died.

Any thoughts on possibilities of what's wrong? Or ways to test it off of the bike?

It's just the cheap looking sensor that comes with the kit - this is the kit I have - https://www.johnnynerdout.com/product-page/hub-motor-wheel-kit-750w

 

[harryS]

Possible causes.
1. Loose connection.
2. You broke all the splines on wheel, so it is not spinning.
3. Broken sensor,

The problem with testing them is getting access to the wires. If you're electrically skilled, you can slit the cable to expose three wires. Probably red, black,and white. I just had to open one up o shorten the cables.

Leave it connected to the bike. Put a meter on the white and black wires. IT will flip from o to 5 volts as the pedal spins if the sensor is working, Almost easier to buy a new one than test the old one.

They ate $8-20 dollars on amazon, ebay and aliexpress. They come with either 6 magnets or 12 magnets, and fit on left side or right side. Would be smart to buy one that fits on the same side and has the magnets count you want. Maybe Mr, Nerdout will sell you a spare. You can buy them elsewhere, but the cables will be too long.

 

[jfny1978]

Possible causes.
1. Loose connection.
2. You broke all the splines on wheel, so it is not spinning.
3. Broken sensor,
View attachment 195333
The problem with testing them is getting access to the wires. If you're electrically skilled, you can slit the cable to expose three wires. Probably red, black,and white. I just had to open one up o shorten the cables.

Leave it connected to the bike. Put a meter on the white and black wires. IT will flip from o to 5 volts as the pedal spins if the sensor is working, Almost easier to buy a new one than test the old one.

They ate $8-20 dollars on amazon, ebay and aliexpress. They come with either 6 magnets or 12 magnets, and fit on left side or right side. Would be smart to buy one that fits on the same side and has the magnets count you want. Maybe Mr, Nerdout will sell you a spare. You can buy them elsewhere, but the cables will be too long.

Thank you. Sadly, Johnny Nerdout doesn't sell replacement PAS.

Should any new PAS that has the same yellow connector work, or could there be compatibility issues?

For example I like the looks of this one: https://www.amazon.com/Magnets-Assi...ectric+bike+pedal+sensor,aps,100&sr=8-16&th=1

 

[harryS]

I would expect the pinouts on the yellow plug to be standard, You will have a 35 inch cable to deal with.

These sensors put out their own distinctive pulse trains which may or may not be recognized by your controller.

For example, I just replaced a 6 magnet sensor with a 12 magnet model. Both sensors and controller made by same company, but the 12 sensor unit required me to set the display up for 12 magnets before it would work, Then again, not all displays really care about that,

I went to 12 magnets because my wife wanted the PAS to kick in fast like her other ebike. Appears to do so.

 

[jfny1978]

I would expect the pinouts on the yellow plug to be standard, You will have a 35 inch cable to deal with.

These sensors put out their own distinctive pulse trains which may or may not be recognized by your controller.

For example, I just replaced a 6 magnet sensor with a 12 magnet model. Both sensors and controller made by same company, but the 12 sensor unit required me to set the display up for 12 magnets before it would work, Then again, not all displays really care about that,

I went to 12 magnets because my wife wanted the PAS to kick in fast like her other ebike. Appears to do so.

Thank you. I really appreciate you sharing your knowledge with me.