Help Troubleshooting after riding over railroad ties..

[Fred987]

I have a Voila mart 48v 1000W with only 200 miles on it. I pretty much only rode it on pavement and it worked great until... I decided to ride down some train tracks. I was going pretty slow and only made it about 300' of bounching up and down before a grinding noise and no forward motion occured. If I push I can get a little, very little, motion out of it but if I stop walking I can easily hold it in place with it just shuddering. Sometimes I have to push it 40 or 50+ feet before it kicks on and starts the shudder. I checked wiring and didnt see any issues and I replaced the controller. So I'm Assuming the only thing left is the wheel but I wanted a 2nd opinion before I went that route. Is there a possibility it could be the battery? I dont know what symptoms broken connections in the battery would be or if that could even be a thing.

I tried uploading a video but it wasnt allowed so I hope this link to the video will

Bike.MOV

drive.google.com

Thanks for any input

 

[theemartymac]

So assuming you have checked the axle/dropouts/derailleur/chain/brakes/fender for any displacement, rubbing, or obvious hang ups (cables too), I would lean towards a stripped gear (if it has any), or less likely but possibly a cracked bearing. If that is a direct drive hub, maybe a magnet or part came loose inside as well and is binding up somewhere.

After a good physical inspection, I would disconnect the hub power cable and see if the wheel spins smoothly, if not, pull the wheel and see if the axle spins when nothing else is in contact with it (brakes/chain/frame). If there is resistance to the axle when it is all disconnected, you have something broken inside the hub and will need to open up the hub to see what it is. Thay may need a bike shop tech if you aren't technically saavy. Otherwise, watch a couple of google vids on hub disassembly first.

Now if the axle and bearing are rotating smoothly, it is possibly a controller output issue, and perhaps a throttle or sensor failure. Check that the cadence sensor hasn't shifted, and that the throttle and cables haven't been pinched somewhere creating an intermittent short.

 

[AHicks]

It may have dropped a magnet.

 

[tomjasz]

gear replacement?

Web site reads "Motor: Brushless gearless. #AHicks may well have nailed it!

 

[theemartymac]

I've also seen some references to stuttering and grinding as a symptom of a three phase short or hall sensor failure, but those are all internal fixes as well, so worth chasing the easy stuff down first.

 

[tomjasz]

I've also seen some references to stuttering and grinding as a symptom of a three phase short or hall sensor failure, but those are all internal fixes as well, so worth chasing the easy stuff down first.

good call !!!

 

[Fred987]

Thanks for the replies.
I can not find any binds or broken gears. it pedals fine and the wheel spins freely by hand without noise.
I did not open the motor. If it did drop a magnet, or a sensor is that a fix I can easily do or is a wheel replacement easier

 

[tomjasz]

Thanks for the replies.
I can not find any binds or broken gears. it pedals fine and the wheel spins freely by hand without noise.
I did not open the motor. If it did drop a magnet, or a sensor is that a fix I can easily do or is a wheel replacement easier

Google this, ebike hub motor replace magnet

 

[theemartymac]

Magnets can be re-epoxied as long as nothing physically disintegrated. If a three phase wire just came loose it can be sauntered. If the cable is cracked or melted it's a little more involved to replace the whole cable, but doable. i have no idea if you can source or replace the internal sensors though.

If it's off warranty, open it up and see. If it's still under warranty, definitely try and RMA it before you open it up. It's almost certainly not worth enough to engage a repair shop to repair it, but it's worth the lesson to try and fix it with the help of some youtube videos and a multimeter.

 

[AHicks]

Thanks for the replies.
I can not find any binds or broken gears. it pedals fine and the wheel spins freely by hand without noise.
I did not open the motor. If it did drop a magnet, or a sensor is that a fix I can easily do or is a wheel replacement easier

If the wheel is spinning free, with no weird noises, it's not a magnet. A loose magnet would be dragging noticeably.