Bafang Max 250w motor .. confused, pls help!

[Homet]

Hi all,
After some considerable searching, we finally settled on a bike for my wife. She wanted a stepthrough, foldable with 20” wheels with a Bosch motor. I couldn’t find anything with the Bosch but I did find a NCM Paris Max with a Bafang Max so I ordered it.
The bike arrived today and it looks pretty decent but I just can’t figure out how the motor works. On both the Bosch and Yamaha the assistance settings supplements your input so Assistance 1 may be 30%, 2 might be 50% etc but on the Bafang, the manual has no mention of this at all but instead provides a table that reads an awful like something from any hub drive motor (see attached).
Can anyone with some experience of this motor please clarify how this thing works?

NCM Paris Max

 

[D.Unwin]

this is a pic of the 750w configuration but going off the picture the assists indicate the percentage of the motor, dont take my word for it i just found this on Google

 

[Homet]

Thanks Stefan but I was trying to compare the Bafang MID drive with the Yamaha and Bosch mid drive motors. I found a page (see link below) that says that the Bafang is only capable of 100% assistance at level 5, the max level. So it simply matches the user input so doubles his power. Both the Bosch and Yamaha can do way better!

Bafang Max Drive

 

[Stefan Mikes]

Thanks Stefan but I was trying to compare the Bafang MID drive with the Yamaha and Bosch mid drive motors. I found a page (see link below) that says that the Bafang is only capable of 100% assistance at level 5, the max level. So it simply matches the user input so doubles his power. Both the Bosch and Yamaha can do way better!

Bafang Max Drive

Sorry, my fault.
Deleting my silly post.

 

[Homet]

No worries Stefan!

 

[theemartymac]

If that is only a cadence sensor bike, the bafang settings are just speed limits as suggested by D.unwins pic. It's all or nothing with max power output until it reaches the top speed cutoff for the given PAS level. It certainly makes those models feel a little jumpier and lacks the refinement of the Bosch and other premium drives.

If it has a torque sensor like I think it does (I could be wrong, but I thought the max was a combination cadence/torque drive), you can adjust the currents and the start/stop pressures in the settings with a programming cable and the software. That will tune the assist to be power output based right where you want it, and not just a top speed cutoff. This can give you a more refined or progressive power curve.

Bafang Max Drive - configuring

Background Doesn’t seem to be a lot of info out there yet on configuring the Bafang Max Drive even though e-bikes with this mid drive are becoming more popular, so thought I’d document my experience with it as a starter for others interested in configuring it. My e-bike My requirement was a...

endless-sphere.com

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[Homet]

Thanks, it does have a combination of sensors and I assumed that the motor would be ready-programmed to emulate the market leaders! I’m not too happy trying to hack the thing, especially after I paid £1700 for it a few days ago.
I just don’t understand why they thought 100% max assistance was enough!
Do you think the graphic on that page could be wrong?

 

[theemartymac]

Thanks, it does have a combination of sensors and I assumed that the motor would be ready-programmed to emulate the market leaders! I’m not too happy trying to hack the thing, especially after I paid £1700 for it a few days ago.
I just don’t understand why they thought 100% max assistance was enough!
Do you think the graphic on that page could be wrong?

Like I said in your other thread, the percentage output is marketing bullshit. A motors peak output is 100% no matter what they try to call it. You can't actually give 110% effort - 100% is by definition Max output. The difference is the nominal rating (what the software/firmware limits are) not the potential of the motor if unrestricted. And there is no industry standard for power ratings, so they all have their own numbers that can't be compared on paper.

Bafang doesn't try to compare with the refined motor builders. They make economical motors with good output. They also inflate their torque ratings compared to other builders, but that's a different issue. So where Bafang might say peak torque is 80NM at 100% (but probably software/firmware limited), and Bosch says its 40NM (but capable of 320% boost), they are saying the same things in their own marketing speak. You have to actually ride and test them to see if one wildly outperforms the other. And be warned, Bafang is not known for refined power curves. It can usually be programmed to be much better than stock, providing the builder has not intentionally added their own controller and display firewalls, but out of the box they won't be as smooth or refined as a bosch.

 

[Homet]

Thanks, that does make sense. I’m just wondering if I may be better off just getting her a decent hub drive bike instead. Just need to find one with 20” wheels and a torque sensor..

 

[theemartymac]

There is nothing wrong with the Bafang drives, and if you're willing to put a bit of effort in to refine it further they can be just as nice and pleasant to ride as a Bosch or Yamaha. The difference is the Bosch bike costs twice as much for a highly refined product that cannot be tuned any further. The Bafang bike is half as much for a bike that is 'good enough', but generally permits the bike builder or end user to make more adjustments and unlock more raw power after the fact. You just have to pick your poison...

 

[Homet]

But if I mess with it, won’t I lose the warranty?
would anyone know if I put it all back the way it was?

 

[theemartymac]

But if I mess with it, won’t I lose the warranty?
would anyone know if I put it all back the way it was?

Void Warranty - possibly. Would they know - Generally not unless you permanently altered hardware or firmware. If you just program the setpoints in the controller, you can always return them to default. The ethics of it are obviously dark gray if you intentionally try to hot rod your bike then hide it from the manufacturer after you fry a motor. But the techs are not dumb, and they see right through this every day.

But if all you want to do is refine the settings and maybe unlock a top speed limit, that's just tuning. You're not asking the motor to do anything it wasn't designed to do., and you can even extend the life of motors and components if you refine the performance to be smoother and more efficient. Many manufacturers/builders actually provide the passwords to unlock the regional limits and settings right in the owners manual. They recognize that a bike is not a one-size-fits-all item, and just like you can adjust your seat and bars to fit, you can tune the power profiles to suit your needs as well.