Bike suddently refused to move during a stop, generic Chinese E-bike/motorcycle

[jackliu239]

I purchased an second hand generic Chinese ebike, or e-motorcycle because it weights somewhere in between.

I purchase this 2nd hand from someone who only had it for a few month, i had for 2 weeks and it works great, the build quality is really bad, the chain keep falling off but thats another topic.

Anyways so today while riding I came to a stop and when I try to start again the bike give me no power, it has full power, all the lights, horns and such are all working as normal, when I push on the throttle sometimes the wheel jolts forward for like 0.1 second and then stops, this jolting only happens each time I turn on and off the power.

So I think the motor is not competely dead because it does give that jolting action, its also no the battery because power is just fine.

Does anyone have similar experiences like this?

 

[calab]

If its an easy fix, I'd say sell it asap, if you want to ride the pathways and sidewalks then its better to use an old bicycle to convert to an ebike which wouldnt cost much and be 100 times better then what you have. Hub motor $200-300, battery varies but at $500 from a good supplier would do well depending on how far you want to ride and how fast.

Its probably just a loose wire or since its a cheap ass moped, you think they sprung for good quality connectors?
Snip 'em off asap, hard wire them and sell it.\

Next, I'd look at the controller and motor.
The motor for internal wiring that you couldnt see otherwise, like halls, wires or over heated motor.
The controller, about the best you can do is open it up and start smelling and looking for smudges or puffed capacitors. Sometimes you have to look carefully, could be a very small SMT component and if it aint discolored then your SOL.

 

[rick_p]

I had almost identical symptoms on my bike once, it turned out to be the controller, one wire had a bad solder connection to the circuit board. The first thing to check is wiring connections, a loose or corroded connector could easily cause this issue. If all connections are good, then I would suspect the controller. Since repairing controllers isn’t novice work, it might be best to just try replacing the controller with a new one. There’s no guarantee the controller is the problem of course, but they do turn out to be the source of many similar problems, and they’re usually not very expensive.

Calab and I must have been typing at the same time, a lot of similar points and suggestions.

 

[calab]

Check for ignition wires, I come from ebikes not emoped background.
Check your ignition system, key ignition wiring. You might have to spring for a digital multi meter, $15-20 is average price, Harbor Freight USA stores $5-10.

You could also buy a motor tester for $20, but its not necessary.

You might just have to buy a cheap controller of similar specs, they come in brushed or brushless.

If its brushed, could be the brushes are no good.

 

[jackliu239]

so I took everyone's adivce and I got to my controller box, I unploged and plugged every single cable and still nothing works. While I was at the controler cable, I do smell something rotten the closer my nose is to the controller box compartment. I don't have a digital multi meter yet so I havent test out each wire.

edit, I went back again, I think the smell is from closer to the wheel, the box itself has no smell and shows no burn marks, so I think a loose wire is somwhere, but there is no way to fix, because all cable is connected together and I can't pull any of it off, I can only disconnect/unplug from the controller box and I did that for all cables already.

 

[rick_p]

edit, I went back again, I think the smell is from closer to the wheel, the box itself has no smell and shows no burn marks, so I think a loose wire is somwhere, but there is no way to fix, because all cable is connected together and I can't pull any of it off, I can only disconnect/unplug from the controller box and I did that for all cables already.

When you say “rotten” do you mean it smells like burnt plastic or burnt electronics? If so, you will need to track down exactly where that smell is coming from.

I see a fuse, did you check it to see if it blew?