Bafang M620 Quiet Gears

[MartsEbike]

Yeah works well in sealed gearboxes! I can see the appeal of it in those applications but with the m620 having a big hole through to the controller I just don't feel as confident about packing it out with it. The excess may get into places I'd rather it didn't. My experience with the SHC100 is it tends to stay where you put it!

 

[TPEHAK]

The source of the noise might be not only the lack of grease. Inspect the middle gear bearing (the overrun one way bearing) pressed into the larger one gear. The large one middle gear can slide down on that bearing causing the gears rubbing each other making noise (in some cases extremely loud noise). The problem with the middle gear is the helical gear (not straight cut gear) and it causes lateral force under load and the gear can slide on the bearing over time. My 3000W Innotrace X1 controller was able to slide that gear on the pressed bearing.

Helical gears suck, straight cut gears are the best for heavy duty and reliable applications. The only advantage of helical gear is less noise comparing with straight cut gears, but helical gears require specific design solutions to deal with lateral forces (and Bafang did not implement such solutions so those gears can fail).

 

[George of the jungle]

Hi guys,

I was wondering if anybody has upgraded their Bafang M620 motors with the new and quieter gear/rotor available on GreenBikeKit?

The new design is meant to reduce noise. I hope so as you can hear my bike a mile away, it turns heads as I pass by.... Anything which can make it quieter would be a bonus.

Has anyone else done the upgrade and did it make much difference?

I ordered the gear set and have aa knock in hte moter... all the teeth look good and mesh on the bench. It calabrated just fine and of course I got the new roter. I have have it completely apart and can seee no reason. Im about to put the old stuff back in and see what happens.. In the description of the new gears it says you can try to put them in.. Anybody have the same issue ??

 

[Gionnirocket]

I picked up a complete quiet gear motor from GBK for a project that got delayed so I decided to throw it in my current ride to see what it's all about.
It is somewhat quieter, especially at certain cadences and power outputs... but at other times it's just as loud as the original motor. I notice it particularly at low output.. say <100 watt when you're just chugging along on a flat and don't need much assistance. The tone is a little higher pitched as well.
Personally I don't think the difference is worth much if anything.
Then add when I loaded my programming that's a jewel in my 2022 motor... It doesn't behave the same... especially in that same chugging along <100 watt output range. It tends to drop off to zero requireing me to pedal harder. I loaded the programming it came with and it was a little better... But the programming tweaks needed for this motor are definitely going to be different than my other motor to have a similar performance. It's almost as if the torque sensor is calibrated differently.
The model number and firmware version for both motor controllers are identical.
In the program I did notice that the base torque voltage was 147mv.. a little lower than the typical 158 - 160mv but adjusting that made no difference.
Using the Continuous Get feature of the software the torque sensor has the same +/-3200mv top end.
Gotta love Bafang!
I'm going to play with the programing for a bit and then open her up and check the grease. Depending on what I find and if I think it still louder than desired I may Cornhead'r

 

[MartsEbike]

I picked up a complete quiet gear motor from GBK for a project that got delayed so I decided to throw it in my current ride to see what it's all about.
It is somewhat quieter, especially at certain cadences and power outputs... but at other times it's just as loud as the original motor. I notice it particularly at low output.. say <100 watt when you're just chugging along on a flat and don't need much assistance. The tone is a little higher pitched as well.
Personally I don't think the difference is worth much if anything.
Then add when I loaded my programming that's a jewel in my 2022 motor... It doesn't behave the same... especially in that same chugging along <100 watt output range. It tends to drop off to zero requireing me to pedal harder. I loaded the programming it came with and it was a little better... But the programming tweaks needed for this motor are definitely going to be different than my other motor to have a similar performance. It's almost as if the torque sensor is calibrated differently.
The model number and firmware version for both motor controllers are identical.
In the program I did notice that the base torque voltage was 147mv.. a little lower than the typical 158 - 160mv but adjusting that made no difference.
Using the Continuous Get feature of the software the torque sensor has the same +/-3200mv top end.
Gotta love Bafang!
I'm going to play with the programing for a bit and then open her up and check the grease. Depending on what I find and if I think it still louder than desired I may Cornhead'r

Yep it's quieter to a degree but far from silent. I think the issue might be compounded by resonance through the frame. I'm going to try add a thin sound deadening rubber layer between the motor and mount, but the tolerances are fairly tight so might not be able too - or for it to have much effect. I may also add it to the battery compartment. A sheet is only a few quid on Amazon so worth testing.

I've also been considering using an all together different grease. I'm not entirely convinced using SHC100 or Cornhead is the most ideal grease for this application. Both have limited coverage on the gears themselves, so when I next open it up I may try something else. I'll let you know how it goes.

 

[Gionnirocket]

Yep it's quieter to a degree but far from silent. I think the issue might be compounded by resonance through the frame. I'm going to try add a thin sound deadening rubber layer between the motor and mount, but the tolerances are fairly tight so might not be able too - or for it to have much effect. I may also add it to the battery compartment. A sheet is only a few quid on Amazon so worth testing.

I've also been considering using an all together different grease. I'm not entirely convinced using SHC100 or Cornhead is the most ideal grease for this application. Both have limited coverage on the gears themselves, so when I next open it up I may try something else. I'll let you know how it goes.

hmm... That motor is a very tight fit in the mount. That might be near impossible or as you say.. not enough to make a difference.
When you compare the noise to a near silent BBS02B.. It's hard not to be annoyed. That said, I've grown accustomed to it and it is livable.

As for the grease... While I have the QG motor installed I opened up the 2022 motor.

Re-greasing the Ultra motor...is it time?

Why don’t these motors have a Zerk fitting for ease of maintaining Because it's not that type of gear box and it's best to remove the old grease especially if changing type. Even if using the same grease it needs to be evenly distributed and using too much could easily bleed over into the...

forums.electricbikereview.com

 

[MartsEbike]

hmm... That motor is a very tight fit in the mount. That might be near impossible or as you say.. not enough to make a difference.
When you compare the noise to a near silent BBS02B.. It's hard not to be annoyed. That said, I've grown accustomed to it and it is livable.

As for the grease... While I have the QG motor installed I opened up the 2022 motor.

Re-greasing the Ultra motor...is it time?

Why don’t these motors have a Zerk fitting for ease of maintaining Because it's not that type of gear box and it's best to remove the old grease especially if changing type. Even if using the same grease it needs to be evenly distributed and using too much could easily bleed over into the...

forums.electricbikereview.com

It's tight but not completely form fitting. So there is a possibility, but alas I'll have to see. I have my doubts, but think it's worth a look. Testing with industrial plasticine will give a good idea of where (if any) there is clearance between the mount and motor for it to be applied.

The grease pics in your link look very clean after riding for 4000 miles. When I opened it up my motor the first time the grease was discoloured, dirty and black in places! I replaced the rotor due to clear signs of wear on the teeth. I think it could be improved by another grease and/or coating. I will obtain some stuff from my work for testing but as you say, you become accustomed it to a degree, so not something I've put a much effort into up to now. I'll have a go when I next feel a grease change is needed.

 

[Gionnirocket]

It's tight but not completely form fitting. So there is a possibility, but alas I'll have to see. I have my doubts, but think it's worth a look. Testing with industrial plasticine will give a good idea of where (if any) there is clearance between the mount and motor for it to be applied.

The grease pics in your link look very clean after riding for 4000 miles. When I opened it up my motor the first time the grease was discoloured, dirty and black in places! I replaced the rotor due to clear signs of wear on the teeth. I think it could be improved by another grease and/or coating. I will obtain some stuff from my work for testing but as you say, you become accustomed it to a degree, so not something I've put a much effort into up to now. I'll have a go when I next feel a grease change is needed.

Well after 100mi on the QG motor I'm convinced that though at a mostly lower dB level... it's far from quiet and I find it equally annoying.
It's going to get the cornhead treatment as I haven't tried it yet and I'm curious about that as well.

As for the tuning difference I dropped the Delta Voltage setting for 0 - 5kg down to 50 from 300 and set Start kg for Spd0 to 10 from 20. It's not fine tuned but is behaving pretty much like my 2022 motor is. Those settings in the stock programming are 200 and 20 respectively.

We're in for a real cold stretch so I'll probably swap the motors back and grease the QG motor as I hate messing with programming in bad weather.
Plus it'll give me something to do when it's not nice enough to ride. And sometimes I just like fixing what ain't broke.