Radwagon.. New high pitched ringing sound from motor.

[Peter R.]

I have around 500 kms on my Radwagon. Around 40 or 50 kms ago I noticed a high pitched ringing sound coming from the motor. It starts around 300 watts and gets louder with more power. This noise was not there when I got the bike. It has become very irritating and is destroying my enjoyment of the product.

I have a video of the noise. You need to use headphones or good speakers to get the high frequency noise. I am in pas 3 and am peddling and then stopping. The noise is there when the motor is on.
It is on dropbox at noisy radwagon.

The rear wheel is true and the spokes are tight. The connector from the controller to the motor has been unplugged and reconnected with no change to the noise. The brakes are adjusted and not rubbing.

If anyone has any ideas what could be causing this please let me know.

 

[Robie]

Get that vid. on. endless-sphere.com they will know. Sounds like something rubbing motor housing internally.

 

[jasonhere]

I have the same issue. I bought my radwagon a couple of weeks ago. Overall its a good bike but I hear chirping when riding with Pedal Assist regardless of the level or the gear. Although, i dont hear it when using the throttle only. I contacted the company and they said it was normal but I dont think so. Here is a link to the sound.

Any advice would be greatly appreciated!

 

[HelloEbike]

@Peter R. @jasonhere - Please tighten the two rear nuts that attached the tire to the bike frame. I had the same problem and by tightening the rear nuts, this completely solve my problem.

 

[jasonhere]

@Peter R. @jasonhere - Please tighten the two rear nuts that attached the tire to the bike frame. I had the same problem and by tightening the rear nuts, this completely solve my problem.

Thanks @HelloEbike for responding to my post. I tried tightening the two rear nuts and it seems to have changed the sound a little but but did not eliminate the issue. I had a bike shop try to tighten it and still the same. However, thank you for your advice. If you have any other suggestions, please let me know. @Peter R. did you have any luck?

FYI... I got the response from RadPower below:

I watched the YT video again and agree that it sounds exactly like all of our shop bikes and I do not think a replacement rear wheel is warranted. Maybe one of the screws holding the wood panels or rear wheel cover on is a little loose and the washer is vibrating, adding to the noise output?

Although we use sine wave controllers which help reduce the electrical resonance and smooth out the motor, brush less motors naturally have a small vibration like this under load.

 

[HelloEbike]

@jasonhere I had another RadWagon making similar sound. I hired a bike mechanic from Velofix.com to come to my house to check it out. He determined the sound was from the rear brake pads rubbing against the brake rotor. He tried adjusting the brake pads, it reduced the noise somewhat but not completely. He said the rear brake rotor was not completely straight. It wobbles just a little bit, enough to cause it to rub against the brake pads and produce the sound. To eliminate the problem, I probably have to buy better brake pads and rotor like Avid BB7. Good luck.

 

[walawn]

@HelloEbike take off rear caliper just to make sure and test ride in controlled setting so you can eliminate everything else (i.e. internal abnormal motor sound)

 

[M.D]

I dont get the sound but I hear that clicking sound on my front tire. Did you have any issue with your spokes needing tightening?

 

[christob]

@jasonhere I hired a bike mechanic from Velofix.com to come to my house to check it out. He determined the sound was from the rear brake pads rubbing against the brake rotor. He tried adjusting the brake pads, it reduced the noise somewhat but not completely. He said the rear brake rotor was not completely straight. It wobbles just a little bit, enough to cause it to rub against the brake pads and produce the sound. To eliminate the problem, I probably have to buy better brake pads and rotor like Avid BB7. Good luck.

My LBS told me the same thing (brake rotor just barely out of perfect-true, thus "wobbles")... about a light repetitive scraping sound coming from the front wheel. And it was brake pads rubbing on the rotor, but the second time I took it in to have everything looked over (for a long-standing chirp from the back, hub wheel), they readjusted everything, and the front scraping completely disappeared. Which was very nice. I don't know if that was a function of a different technician working on aligning everything vs the first time quick review… I did not buy a new rotor!