Speedway Leger noise from rear wheel

andrei-m

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My electric scooter is Speedway Leger, made in 2020. It has 850km on odometer.

When the speed is around 11km/h, the rear motor is creating a metalic noise, unusual from the typical Minimotors whining sound at acceleration.

The metalic noise is so pitchy and loud that is scaring people at about 20 meters away. Also is very unpleasant noise. What could be the cause of it?
The only thing that happened to this scooter during it's lifetime was a puncture that I fixed myself.

Below is a recording of what the metalic noise sounds like.

https://youtube.com/shorts/TQ9bbPLUBVI
 
If it's a new problem, and never did this before, was it sudden onset, or gradual?

If sudden, what happened just before it started?

If it's been gradual, it could just be bearing wear, might have to replace the bearings in the side covers.

If it's sudden, it could be a wiring fault if it uses hall sensors, causing one or more of them to give signals the controller has a hard time reading, so the motor drive isn't correctly sync'd with it's rotation. Or a mechanical failure (something bent, rubbing, etc).


If it's not a new problem (or the scooter is new to you so you don't know when it started), and happens only at that speed, it's probably a resonance amplified by the frame/etc. Sometimes changing to a different controller (FOC, sinewave) may help, if it's using a trapezoid type.

andrei-m said:
My electric scooter is Speedway Leger, made in 2020. It has 850km on odometer.

When the speed is around 11km/h, the rear motor is creating a metalic noise, unusual from the typical Minimotors whining sound at acceleration.

The metalic noise is so pitchy and loud that is scaring people at about 20 meters away. Also is very unpleasant noise. What could be the cause of it?
The only thing that happened to this scooter during it's lifetime was a puncture that I fixed myself.

Below is a recording of what the metalic noise sounds like.

https://youtube.com/shorts/TQ9bbPLUBVI
 
Thanks for reply. The noise at 11km/h speed started to appear a while ago, not sure when exactly. I can't ignore it anymore.

Should I change the bearings then? It's hard time finding the bearings specs for it, I reached out to Minimotors and they try to make me buy bearings from him rather then sharing the bearings specs so that I can order better quality aftermarket bearings.

From the different online sources, I built an understanding that Minimotors (they build Speedway Leger) don't put hall sensors in the motor wheel. How could I check if the motor wheel does have hall sensors? Also I am reading online that Minimotors controllers are sine wave, so not sure if option for swapping to sine wave or FOC is doable.

Thanks,
Andrei

amberwolf said:
If it's a new problem, and never did this before, was it sudden onset, or gradual?

If sudden, what happened just before it started?

If it's been gradual, it could just be bearing wear, might have to replace the bearings in the side covers.

If it's sudden, it could be a wiring fault if it uses hall sensors, causing one or more of them to give signals the controller has a hard time reading, so the motor drive isn't correctly sync'd with it's rotation. Or a mechanical failure (something bent, rubbing, etc).


If it's not a new problem (or the scooter is new to you so you don't know when it started), and happens only at that speed, it's probably a resonance amplified by the frame/etc. Sometimes changing to a different controller (FOC, sinewave) may help, if it's using a trapezoid type.

andrei-m said:
My electric scooter is Speedway Leger, made in 2020. It has 850km on odometer.

When the speed is around 11km/h, the rear motor is creating a metalic noise, unusual from the typical Minimotors whining sound at acceleration.

The metalic noise is so pitchy and loud that is scaring people at about 20 meters away. Also is very unpleasant noise. What could be the cause of it?
The only thing that happened to this scooter during it's lifetime was a puncture that I fixed myself.

Below is a recording of what the metalic noise sounds like.

https://youtube.com/shorts/TQ9bbPLUBVI
 
andrei-m said:
Thanks for reply. The noise at 11km/h speed started to appear a while ago, not sure when exactly. I can't ignore it anymore.

Should I change the bearings then? It's hard time finding the bearings specs for it, I reached out to Minimotors and they try to make me buy bearings from him rather then sharing the bearings specs so that I can order better quality aftermarket bearings.

If it *only* happens at that one speed (meaning it doesnt' happen until you reach that speed, and it goes away once you're above that speed) it's almost certainly not mechanical (at least, not bearings). It'd be much more likely to be a phase timing or other similar problem, resonating with the motor casing and scooter body to amplify the vibrations into audible sound.


A bearing problem will usually make it harder to turn the wheel even by hand, and it will also heat up the side covers and axle (because the bearings are mounted on them), though the change might not be detectable without a thermometer. The sound may start at a low volume and low pitch at even just barely rotating speeds, and go up in volume and pitch as the wheel gets faster; higher loading on the wheel (more weight) may cause the volume to go up but not change the pitch. Depends on what specific problem the bearing has as to what noise it might make.

Bearings as they wear may also allow side-to-side play (wiggle) in the motor on it's axle, especially if they're really bad.


If they won't tell you what the bearings are, you'd have to open the motor cover and look at them. It's usually marked on the little side cover of the bearing itself (either plastic or metal), or on the rim of the outer bearing race, like this randomly picked from google:
https://www.fagbearing.cc/SKF-bearings/6204_RZ_SKF_55004.html
SKF-Bearing-01[1].jpg
Once you have the numbers, you can ask any bearing store (like that one) or places like McMaster-Carr, Grainger, etc., and they will find the right match for it. If it has no numbers, then you can measure it (like with some cheap digital calipers) and give those measurements to those places, and they can find the right one for you that way.




From the different online sources, I built an understanding that Minimotors (they build Speedway Leger) don't put hall sensors in the motor wheel. How could I check if the motor wheel does have hall sensors? Also I am reading online that Minimotors controllers are sine wave, so not sure if option for swapping to sine wave or FOC is doable.

If it has hall sensors, there will be several (5+) small thin wires to the controller in addition to the main thick three phase wires.

If it's sensorless (no halls), it'll just have the three thick phase wires.

Either kind can be used with controllers that are sine, FOC, or trapezoidal, as long as the controller supports sensorless operation for motors without them.
 
amberwolf said:
andrei-m said:
Thanks for reply. The noise at 11km/h speed started to appear a while ago, not sure when exactly. I can't ignore it anymore.

Should I change the bearings then? It's hard time finding the bearings specs for it, I reached out to Minimotors and they try to make me buy bearings from him rather then sharing the bearings specs so that I can order better quality aftermarket bearings.

If it *only* happens at that one speed (meaning it doesnt' happen until you reach that speed, and it goes away once you're above that speed) it's almost certainly not mechanical (at least, not bearings). It'd be much more likely to be a phase timing or other similar problem, resonating with the motor casing and scooter body to amplify the vibrations into audible sound.

Thanks for the suggestion. I would like to check on this phase timing or similar problem.

I have a multimeter and hands-on experience with electronics. How can I check if the controller has phase timing issue? Or it could be even the eY3 acceleration throttle issue? I guess I should open the deck and disconnect the 3 thick wires going to the rear motor wheel then use the multimeter voltage test on wires from controller side. Or do i need an oscilloscope to identify phase timing?

Thanks again
 
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