Pace 350 ghosting (motor running when not pedaling)

[lra724]

Note: I posted this on Reddit and they suggested I see if this forum has had experience with this.

I bought an ebike a few months into the pandemic. I live in Canada and continued to ride it into the winter months. On one cold day I was walking my bike to a pole to lock it when it started lurching forward. I was able to hold on to it and put it on the side and turn off the battery. It scared the **** out of me.

It happened again when I arrived back at my apartment. The screen broke.

I took it to the shop I bought it from. After a bit of a fight (they couldn't find anything wrong with it and wanted to charge a fortune for the screen to be replaced) the manufacturer ended up telling the shop they would replace the bike.

I now have a new bike and it's been working fine, until I went skating a month ago. It starting moving while I was walking it on the sidewalk and a nice stranger helped me wrestle it down.

I'm now worried about it and wonder if it's worth getting a replacement. I've already decided to not ride it below 0'C anymore. And am trying to get better about turning the battery off everytime I get off it.

Any thoughts what's going on? Has anyone had this happen to them before?

To answer some questions others asked me:
1. The brakes should work to cut off the motor, I just wasn't able to when the bike lurched forward.
2. It moved fast, so it may be a short/stuck throttle/controller issue? I don't think it's the freewheel as I dont see the pedals move when I walk it, but who knows...
3. The third time it happened the bike had been stored outdoors overnight. I don't remember it being wet conditions any of the 3 times it happened.

 

[6zfshdb]

I've had this same issue with two different e-bikes and it is indeed scary! In both cases, I traced the problem to a bad three wire throttle connector. There was an intermittent open in the ground wire which caused the motor to go full throttle. Temperature changes or just touching the wiring harness in a certain way caused the problem to occur.

In order to diagnose the problem, I put the bike on a work stand with the rear wheel off the ground. I turned on the power, turned the bars and manipulated the wiring harness until I found the spot that made the motor start. In my case, the fault was where the ground wire entered the throttle connector body. As a temporary fix, I cut out the bad connector and soldered the wires together. I was about to order a new wiring harness when the manufacturer announced a recall on the bike for this same problem. They sent me a new one at no cost and I installed it myself.

This may or may not be your problem since my bikes were not made by Aventon but it's something to check out.

 

[lra724]

I've had this same issue with two different e-bikes and it is indeed scary! In both cases, I traced the problem to a bad three wire throttle connector. There was an intermittent open in the ground wire which caused the motor to go full throttle. Temperature changes or just touching the wiring harness in a certain way caused the problem to occur.

In order to diagnose the problem, I put the bike on a work stand with the rear wheel off the ground. I turned on the power, turned the bars and manipulated the wiring harness until I found the spot that made the motor start. In my case, the fault was where the ground wire entered the throttle connector body. As a temporary fix, I cut out the bad connector and soldered the wires together. I was about to order a new wiring harness when the manufacturer announced a recall on the bike for this same problem. They sent me a new one at no cost and I installed it myself.

This may or may not be your problem since my bikes were not made by Aventon but it's something to check out.

Thanks! I just tried fiddling with the wire that goes into the throttle to see what happens and had no luck. I might try putting it out in the cold for a bit to try to mimick what happened before.

Which type of bike did you have before that got recalled? It might be good to have that in my back pocket if I need to go back to the shop.

 

[mjeds]

most bikes have walk mode.

on most of them it is activated by holding a specific button for 3-5 seconds.

are you accidently pressing/holding one of the buttons?

 

[lra724]

most bikes have walk mode.

on most of them it is activated by holding a specific button for 3-5 seconds.

are you accidently pressing/holding one of the buttons?

Thanks for the suggestion. The walk mode is awkward (you have to keep pushing down on a button) and then the bike moves slow. This issue is like trying to hold down a bike trying to go full speed.

 

[mjeds]

Thanks for the suggestion. The walk mode is awkward (you have to keep pushing down on a button) and then the bike moves slow. This issue is like trying to hold down a bike trying to go full speed.

hmm all 4 of my bikes the walk mode is activated by holding the down button for 3 seconds and it moves fast, like 3-4 mph I hate it, I don't need power assist while walking

 

[FiremarshallDave]

I like that your new protocol is turn off the bike when your done riding. Off at the control screen, then off at the battery. I have made that mistake before and it was with a twist throttle. I forgot to power down and twisted the throttle putting the bike away. I used to power down in the garage, not any more. I would guess you have a short and not a water problem. The coefficient of linear expansion would mean the wires contract when cold leading me to think it's a short. Intermittent electrical is the hardest thing to fix. If your using a throttle I would just get a new one before your next ride ($15.?). Look at the way your wires are routed are they being run fairly taught or in a way they could be pinched? Could be the way your shop is doing something that others are not. I go back to... what are the odds that 2 separate bikes would have the same problem. Could be a bad batch of components that ended up with one builder. It could also be something causing the throttle not to fully power down. Is it bumping against another component? I would get a thumb throttle, it's safer than a twist throttle and cheaper than a doctor bill. I don't use cadence sensors but the short could also be there. just unplug the cadence unit and see if you can recreate the problem. The bike works without it. I don't think that's the problem from what you described.

 

[6zfshdb]

Thanks! I just tried fiddling with the wire that goes into the throttle to see what happens and had no luck. I might try putting it out in the cold for a bit to try to mimick what happened before.

Which type of bike did you have before that got recalled? It might be good to have that in my back pocket if I need to go back to the shop.

My bikes are Pedegos

Here's a link to the recall:

Pedego Electric Bikes

One of the most established U.S. e-bike brands, Pedego makes excellent mid- and lower-cost electric bikes with a five-year warranty and anti-theft protection.

electricbikeaction.com