Bafang Ultra what’s the difference between G510 and M620

[Dave Sloan]

I see bikes advertising both G510 and M620 as Ultra. Can anyone clarify the difference? Thanks for your help.

 

[TForan]

I don't think there is any difference. The only change I know of is the switch from nylon to the metal gears.

 

[Ken M]

I think it was the upgraded metal gears as well.

 

[ClicknTwist]

Anyone know if the Bafang M620/G510 motors come pre lubed? My original nylon geared motor just died @13k miles.

 

[JRA]

The M620's I have cracked open direct from the factory have a very little amount of white lithium in them. I remove an replace with a few tablespoons worth of John Deere Corn Head grease and that lubricates and quiets them down nicely. Others have had success with different grease the main thing is that from the factory there isn't enough and why people complain about them being loud. Steel on steel gears without grease will be loud and wear faster.

 

[Open_Mind]

The M620's I have cracked open direct from the factory have a very little amount of white lithium in them. I remove an replace with a few tablespoons worth of John Deere Corn Head grease and that lubricates and quiets them down nicely. Others have had success with different grease the main thing is that from the factory there isn't enough and why people complain about them being loud. Steel on steel gears without grease will be loud and wear faster.

So why they don't put enough grease at the factory ?

 

[Tom@WashDC]

The M620's I have cracked open direct from the factory have a very little amount of white lithium in them. I remove an replace with a few tablespoons worth of John Deere Corn Head grease and that lubricates and quiets them down nicely. Others have had success with different grease the main thing is that from the factory there isn't enough and why people complain about them being loud. Steel on steel gears without grease will be loud and wear faster.

I concur. Same issue with mine.

 

[ElevenAD]

Anyone know if the Bafang M620/G510 motors come pre lubed? My original nylon geared motor just died @13k miles.

Yes they come "pre lubed" but Bafang's definition of lubed is different from most lol, they put very little grease in their motors!
Maybe you just need to replace a busted gear? If i had one of those original motors i would for sure try and keep it going, not a sturdy as todays Ultra but they are even smoother and quieter!

 

[ElevenAD]

So why they don't put enough grease at the factory ?

One can only speculate but im pretty sure they have their reasons, meaning its not something they just overlooked.

 

[Chargeride]

My bbshd was practically silent, I rode an ultra powered fatbike owned by the guy I was buying the bbshd off.
The bike was very heavy and sounded like a straight cut race gearbox.
Totally put me off ever buying one

 

[Tom@WashDC]

My bbshd was practically silent, I rode an ultra powered fatbike owned by the guy I was buying the bbshd off.
The bike was very heavy and sounded like a straight cut race gearbox.
Totally put me off ever buying one

My BBSHD seems runs nearly silent. When I got my Ultra, I was concerned about the noise. Not loud, but loud compared to the BBSHD, The noise did quiet down after the first few hundred miles. Then I opened it up to reveal a paltry amount of factory grease. I filled it with John Deer Corn Head grease and it reduced the noise by 60-70%?

 

[Neverlost]

How hard is it to open and lube.

 

[Tom@WashDC]

Easy to open and grease, lots of videos on Youtube. May take you 1.5 - 2 hours the first time. After that, about 1-hour.

My Motor after initial 500-600 miles with factory grease. At this stage I added a few ounces of Corn Head Grease and closed it up.

Reopened it at about 2,500 miles to check on the Corn Head grease. I was very satisfied.

Just last week I opened it with about 3,500 miles on it, and it looks the same. Loads of Corn Head grease in all the right places.
FYI, I wouldn't get to hung up on what type grease. There are lots of different opinions here on the board, I'm sure any of the recommended ones are better than what you currently have from the factory.

 

[Chargeride]

Thats good to hear, but its much heavier than the bbshd, does it actually produce more power/ torque

 

[teskow]

Heavy sticky grease will cause a reduction in the efficiency of the motor due to increased friction of the heavy lubricant.

 

[JRA]

Heavy sticky grease will cause a reduction in the efficiency of the motor due to increased friction of the heavy lubricant.

Corn head grease is a polyurea based 0 grade grease that liquify's during use which doesn't effect efficiency (as much) and returns to grease when static. My motor becomes quieter as it operates for example. #2 grade lithium greases remain thick while in use which can reduce efficiency. Regardless a certain amount of grease is desired in order to reduce friction between the steel gears that causes wear. There can be too much of a good thing though and the amount shown above is a good example of what constitutes a proper amount.

 

[Tom@WashDC]

Thats good to hear, but its much heavier than the bbshd, does it actually produce more power/ torque

I believe the torque rating is the same for both motors. I've got both, they feel the same, but the BBSHD is Cadence sensing, and the Ultra is Torque sensing so there is no real world comparison. They both have enough power to snap a chain of that gives you an idea of thier power.

 

[Chargeride]

Is there a helical gear replacement kit?
I know drag and all , but I want silence!

 

[Tom@WashDC]

How hard is it to open and lube.

Here are the tools you will need to remove the motor and open it.

Start with your bike upside down, I think it's easier.
Remove the chain from the chainring
Remove the right and left cranks with the 8mm Hex and Crank Remover tool. (I don't remove the left crank, it's optional)
Remove the chainring nut and chainring with the Bafang Motor tool.
Remove the plastic upper cover on the left side of motor with the T10 Torx tool
Remove the three bolts holding the motor in the cradle using the 13mm socket and 5mm Hex. You may have to tap the bolts free.
As you lift the motor from the cradle, carefully disconnect the battery/power, and the motor controller connections. You will have at least two, maybe three or four connectors if you have a brake light and/or shift sensor.
Remove the six motor casing screws with 4mm Hex.
My motor case splits apart by hand, you may have to tap it or use a small screwdriver to split the halves initially. Take care to preserve the paper gasket. It's pretty durable and may be reused.
There are three guide pins that assist you when putting the motor back together. They can fall out, just stick 'em back in.
Reassemble in reverse is.
CAUTION: Be careful not to crimp any of the controller connectors and wires when reinstalling back into the frame.

 

[Tom@WashDC]

Is there a helical gear replacement kit?
I know drag and all , but I want silence!

Not that I am aware of.
My is Ultra not silent, but it is damn quiet, now after breaking in with Corn Head grease. My friend has Sondors Rockstar w/Ultra. We've been riding together 4 days a week for 2+ years. His motor is considerably louder than mine even after he installed Corn Head grease. We concluded it is the resonance, or amplification coming from his aluminum battery downtube chamber. It's a big aluminum chamber. My bike is carbon fiber, and does not amplify the motor noise.