Geared Hub motor Questions

[yooper2001]

What would cause an increase in torque hum? I do not have a temp sensor, but one of those temp stickers, and my motor has never even showed on the sticker minimum 40. It is only a 500w motor 44 nm...and I have never pushed 1000w for more than 30 seconds more than 750w for more than 45 seconds.
I am a large guy...about 235 ibs...
I usually only ride about 10 to 15mph...and the torque hum increased from start to about 10mph...then it quiets down...even under load.

I have the cheap aliexpress 26a controller, and it does seem to change 'modes' at about 15mph when you let off the throttle...it will hum..then hum different...then power down all in about 5 seconds when letting off throttle.
Or do you think the motor just 'broke in' after 1400 miles, as I just got the same bike for son....and his has very minimal torque hum with my fat ass onnit?

I have inspected the gears....and have seen totally bright windings..no burn...and tested but not replaced the bearings...but the wheel free spins forever when I spin it by hand. Or pedal.

If its something damaged or fixable...what can I do to keep it from going downhill?

I am changing eventually to a 1000w 95nm. So I don't stress motor as much, as I usually run 200 to 400w straightaway and 500w up slight inclines.
I am averaging about 27 to 33 wh/mile.
(Moped mode to be nuetral)

I wonder if the new setup will be more energy efficient or less under exact same speeds.

Smaller motor lugging hard. Or bigger motor handling it. Or is energy just energy?

Thank you for your time.

 

[hillslayer@]

If the controller is a square wave vs a sine wave it could be why. Usually at lower speeds the square wave controller can make the motor hum or vibrate.

 

[yooper2001]

It's a 3 mode sine wave controller... I guess the controller maker could have put a square wave band at lower rpms for more get up and go. Wish there was a definte way to tell.

 

[offGridDownUnder]

Wish there was a definte way to tell.

an oscilloscope can show the waveform. Perhaps there is another way.

 

[James340]

Sounds like the controller is in Square wave.Could be a problem with the Hall sensors in the motor.Will the Wheel of the Son's bike connect to this bike?See if it makes the same noise?I have a Square wave controller &it makes noise under load.

 

[yooper2001]

Well I have been doing research....and the Great Amberwolf is right.... The cheap Aliexpress controllers advertise as '3 mode Sine wave'....but what they do is really hybrid. They start off in Square wave...then switch over while cruising. This gives them extra low end performance. This is also what is screwing up my speed sensor readings, as the controller OR display hiccups when it switches back from Sine to Square wave in low RPMs... it's too much...and gives up trying to keep the reading while coasting. You can actually hear the transition.
I will be verifying this next week as I'm getting a 30amp FOC controller for the new hub I'm building. The FOC can't transition to Square because it doesn't work in the same way. Moving from 44NM to 96 NM should minimize the struggling to get my fat ass moving anyhow.

 

[yooper2001]

Well....the FOC sine wave controller was just as loud electrical hum, so I guess it's my motor (and spare movement)

I realize all motor have hum....but mine have gotten 10x louder recently. HEY MOTOR DUDES...what did I do to them to make them hum so loud? They have no friction at all by the brake, and will sit and spin with momentum for a full minute or more unpowered...Is it just my fat ass?

I see no burned or black on the windings...Any ideas? Or am I just being a paranoid princess?

The Halls are all functioning bright and shiny on the tester too. Even used self study wires for the controller.


Here is the sound...starts off quiet...then gets loud around 10 mph...then quiets down around 20...the same in reverse.

 

[neptronix]

This doesn't sound too abnormal. It could be that the gears are making more sound than usual due to wear.
Have you inspected them?
My best bet is that'll be the problem.

Have you ridden this bike offroad some? i hear that's tough on gears.