BD24 high pitched noise

[patm0007]

After 3 or 4 miles the motor starts making a high pitch noise at full throttle, decreased throttle some and in a little bit the noise returns, decrease throttle some more , and on down a little more until it won't run at all, just makes the noise when given some throttle. The sounds like like something is spinning inside .

I took it apart and everything looks good: , magnets , brushes, winding , ect.

any ideas as to what the problem?

Thanks,
Pat

[dogman]

Well, that lets out my first guess, a detached magnet. Did you look at the bearings in the cover at all?

[patm0007]

The bearings turn smoothly. The only other 2 things I can think of are: the armature will spin in the hub when warm and maybe something with the brushes but they look good.
Guess I will put a mark the armature and hub , run it until the noise starts , then check the marks ? Hey, I'm getting good at dis-assembling the motor! Haven't lost any finger tips yet!

Thanks for the input

[dogman]

Armature spins within the motor.

Maybe you are having the same problem I once had on a well toasted motor. The magnets are attached to a ring of steel, that press fits on the axle hub. When hot enough, mine would spin. You could hear the motor spinning inside, but the wheel would not turn. Oddly, in my case it was nearly silent.

If you have any cash, you'd really enjoy the improvement if you upgraded to a brushless motor. When I dumped brushed hub, I really felt a huge increase in range and ability to climb a hill.

[patm0007]

The hub that holds the magnets is spot welded to the axle as well as having splines. The welds are intact.
I'll check the winding assembly but I doubt that's the problem?

Thanks again
PS:
I have a Amped Bike 36 volt rear wheeled direct drive brushless motor on a full suspension bike , 20 ah ping battery with over 5000 mile on it. It's been very dependable except for the throttles. I had replace the hall effect sensor in the throttle(s) and build up the throttle stop to keep the magnet from hitting the sensor. But the bike runs well at about 20-22 mph.

[patm0007]

It was the BMS card going bad until it died. I would have bet the family farm the something was loose and spinning in the hub while the bike was not moving.