Motor making sound like bumblebee stuck inside it :(

The Maestro

Esteemed Pedelecer
May 15, 2008
296
0
Rode my bike home from work yesterday and noticed that it was making a rattley trapped bumble bee sound. Power seemed to be down and speed down by about 30%. I could also feel a rapid vibration through the handlebars.

My motor does make a fair amount of noise normally especially when powering up hills. When just gliding along it normally just makes a humming noise. I've been riding it almost daily for 9 months and I'm familiar with all the normal sounds, this is a different thing. What could have happened? Could it be the battery which I've already had a lot of trouble with?

The sound isn't present if the wheel is lifted in the air so it must require a slight load to cause the load.

Motor type: Suzhou Bafang 37V 26" wheel gearing
 

torrent99

Esteemed Pedelecer
Nov 14, 2008
395
36
Highgate, London
Rode my bike home from work yesterday and noticed that it was making a rattley trapped bumble bee sound. Power seemed to be down and speed down by about 30%. I could also feel a rapid vibration through the handlebars.

My motor does make a fair amount of noise normally especially when powering up hills. When just gliding along it normally just makes a humming noise. I've been riding it almost daily for 9 months and I'm familiar with all the normal sounds, this is a different thing. What could have happened? Could it be the battery which I've already had a lot of trouble with?

The sound isn't present if the wheel is lifted in the air so it must require a slight load to cause the load.

Motor type: Suzhou Bafang 37V 26" wheel gearing
3 possibilities I can think of:
1) Broken wire for one of the hall sensors (thin wires) or motor coils.
2) Broken hall sensor in the motor. (I've read of people replacing these)
3) Broken gear...

Check your connections...
 

flecc

Member
Oct 25, 2006
52,760
30,348
If there's a five wire connector for the Hall sensor wires between the motor and the controller, try unplugging and replugging that first, since these can be a source of troublesome connections.
.
 

The Maestro

Esteemed Pedelecer
May 15, 2008
296
0
Thanks, I'm going to dismantle it and rebuild it all next week I think. I'm finally going to fit a pedal sensor and the electric cut-off brakes so I'll have to take it all apart anyway.
 

Stephen-Gately

Finding my (electric) wheels
Oct 1, 2008
23
0
Rode my bike home from work yesterday and noticed that it was making a rattley trapped bumble bee sound. Power seemed to be down and speed down by about 30%. I could also feel a rapid vibration through the handlebars.

My motor does make a fair amount of noise normally especially when powering up hills. When just gliding along it normally just makes a humming noise. I've been riding it almost daily for 9 months and I'm familiar with all the normal sounds, this is a different thing. What could have happened? Could it be the battery which I've already had a lot of trouble with?

The sound isn't present if the wheel is lifted in the air so it must require a slight load to cause the load.

Motor type: Suzhou Bafang 37V 26" wheel gearing
Have you considered the possibility that a bumblebee is stuck inside your motor?
 

Caph

Esteemed Pedelecer
Feb 29, 2008
440
11
Nottingham, UK
Don't forget to check that mudguard, disk brake, water bottle cage, etc, etc are all tight. I could have sworn that I had a noise coming from my motor about 6 months ago and it turned out to be the water bottle cage, then more recently another noise which turned out to be the mudguard.
 

The Maestro

Esteemed Pedelecer
May 15, 2008
296
0
Don't forget to check that mudguard, disk brake, water bottle cage, etc, etc are all tight. I could have sworn that I had a noise coming from my motor about 6 months ago and it turned out to be the water bottle cage, then more recently another noise which turned out to be the mudguard.
I don't have any of those components but I know what you mean, I thought it was something else rattling or rubbing at first but it doesn't make the noise with the wheel lifted in the air so that kind of means its probably the moto. I recharged the battery and the next day I used the bike it was normal again. I will just have to see how it goes.
 

Rod Tibbs

Pedelecer
Jun 10, 2008
123
0
Miss - Bee - Having

I had exactly the same problem and symptoms a few weeks back and it turned out to be a Hall sensor problem. Replacing the throttle and wiring seemed to do the trick.

Rod