MY1020 BLDC Motor Noise

[1DMF]

I know I'm overvolting a 48v with 60v, but should it really be that noisy?

I'm wondering if some of the vibration and noise is from the fact I'm running a #410 drive sprocket with a #415 chain?

It's only 1/16" difference, but with a 3mm sprocket vs 4.8mm roller width, I assume that will add plenty of vibration and whine to to the riding experience?

 

[InterestedinEVs]

Noise only at higher rpm or lower, too? Every single one of my MY1020's has been poorly balanced. They don't like running above 7000rpm.

 

[Chalo]

It's only 1/16" difference, but with a 3mm sprocket vs 4.8mm roller width, I assume that will add plenty of vibration and whine to to the riding experience?

No, it won't. But using a new chain with a worn sprocket (or a new sprocket with a worn chain) does make noise until the new part wears to match.

 

[1DMF]

Noise only at higher rpm or lower, too? Every single one of my MY1020's has been poorly balanced. They don't like running above 7000rpm.

It is fine up till @ 10MPH, then as the speed increases, it gets really loud and the vibration through the footrests very noticeable.

I doubt it's 7000rpm, it's only meant to be a 3900rpm motor and even overvolting according to the calculator is only 4875rpm.

I think misaligned sprocket due to poor mounting is causing an issue also.

I've got to make better mounting plates so have put the old motor back on, but as I am using only a 1500w controller, having blown my 2000w, plus only having an 11 tooth front sprocket, my performance now sucks, at least it isn't making so much noise!

It seems with the 17x12 inner bore the lowest I can find is 9 teeth in #420, so might have to switch my #415 chain to #420 which will mean running a #420 chain an a #415 rear sprocket as I can't get a #420 with the right centre hub diameter or PCD/BCD.

I can get a 9 tooth #415 sprocket on AliExpress but the inner is 15x12, so I might have to get out the draper tool.

However, I found a #420 sprocket that claimed to be 5mm thick, and as #415 is 4.8mm roller width, and the teeth look 'pointy', it might actually fit, so waiting for that as it has the correct 17x12 inner bore.

This is an expensive hobby and frustrating at times as I seem to be spending more time modding and repairing than actual riding a the moment!

 

[1DMF]

It's only 1/16" difference, but with a 3mm sprocket vs 4.8mm roller width, I assume that will add plenty of vibration and whine to to the riding experience?

No, it won't. But using a new chain with a worn sprocket (or a new sprocket with a worn chain) does make noise until the new part wears to match.

OK, good to know, thanks. :thumb: