ElectricMotorcycleForum.com
Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: dc5dd on April 24, 2014, 04:25:17 AM
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In addition to the SR motor recall I also brought up the sounds I was hearing when the bike did a hard acceleration. For me it seems like the bike did this under hard acceleration like hitting the throttle hard going up a hill or on a straight all way. And I mention that to John. He told me that the engineers are aware of this and they are looking into it they have observe the sound and believe that it is a mix of the motor and the belt or something else but it does not cause any "problems". I hope it stays this way just a little annoying but does not cause a physical problem except for the noise I guess :-\
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My guess is that it is related to the cogging of the motor ( the little bump that the force of rotation is affected by the magnets position) and the tooth of the carbon belt vibration.
When combining these vibration together and the frame that amplify these sound at various speed, there could be alot of various harmonics sound coming from different place.
Personally i think that every Zero model except the one with the Agni and the chain have these sound but a t various frequency.
Doc
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My guess is that it is related to the cogging of the motor ( the little bump that the force of rotation is affected by the magnets position) and the tooth of the carbon belt vibration.
When combining these vibration together and the frame that amplify these sound at various speed, there could be alot of various harmonics sound coming from different place.
Personally i think that every Zero model except the one with the Agni and the chain have these sound but a t various frequency.
Doc
Doc I believe that was very close to the explanation that John gave me.
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Dc5dd,
I created what I think is the first thread on this (got my SR in mid Jan)
The SR has an issue that I believe is related to the syncing between the motor controller and the motor.
If you accellerate hard (WOT) at low speeds you'll hear either a chriping sound or a screeching/squealing sound right?
If you want to demonstrate it to a tech you can try rolling the bike backwards a bit down a hill and then hit the throttle full on. This will amplify the effect at a low speed (like a dealership parking lot).
I've complained about this issue over and over to both the dealership ("uh, they're supposed to sound like that. They're electric") and then finally to Zero. Zero, with their awesome support, agreed to replace the motor.
Long story short: Replacing the motor didn't improve anything by itself but having the shop adjust the motor controller timing/sync make it revert from a squeal back down to a chirping sound.
I highly recommend you talk to Richard at Zero (not the CEO, the other Richard). He's aware of this issue.
//Arvid
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Just a side note having read your post. If I recall in the 2013 owners manual it specifically states to disconnect power to the motor before rolling the bike backwards. That is hit the kill switch before rolling it back then hit it again to go forward. Not sure if this is what you meant when demonstrating for the tech.
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The SR has an issue that I believe is related to the syncing between the motor controller and the motor.
If you accellerate hard (WOT) at low speeds you'll hear either a chriping sound or a screeching/squealing sound right?
Long story short: Replacing the motor didn't improve anything by itself but having the shop adjust the motor controller timing/sync make it revert from a squeal back down to a chirping sound.
That's interesting. I'm glad there's a known diagnosis for this now. It was certainly unusual to me (2013 owner) when I first heard your bike.