M820 or M510 ?

[Jil]

Your practice and your feeling both seem to confirm that this motor M820 has NO PRECEPTIBLE DRAG when riding shut down, this is very good news,
thank you very much !

A good way to test the drag is to put the bike on a workstand, spin the pedals by hand to get the rear wheel moving fast, and then turn the pedals slowly to see if there’s any drag. When I do this with my EP801, I can see that the drag is almost zero. Could an M820 owner try this test? It would be really helpful, as I’m also considering giving the M820 a try (@patdam ?)

 

[Jeromejv]

A good way to test the drag is to put the bike on a workstand, spin the pedals by hand to get the rear wheel moving fast, and then turn the pedals slowly to see if there’s any drag. When I do this with my EP801, I can see that the drag is almost zero. Could an M820 owner try this test? It would be really helpful, as I’m also considering giving the M820 a try (@patdam ?)

Very good idea for testing somehow more seriously than just a subjective feeling if and to what degree the BAFANG M820 has a DRAG in real life...Thank you so much for coming up with this idea @Jil !

Let's wait for the returns of eventual TESTING by those of you here that already have an ebike with this motor and would like to help everyone know better the M820 on that aspect ?
Thank you
@lkdoido
@borysgo2
@patdam

 

[patdam]

soory i am currently broken, one mtorcycle cut me in 2 at my last road exit and i can not use my right hand for several months. But suggestively i will said that M820 is a fewer less drag (very few) than EP801. i will not contest if somebody said that the 2 are free. In any case, i do not think that could be an discus subject or justified to chose one more the other

 

[temon10]

soory i am currently broken, one mtorcycle cut me in 2 at my last road exit and i can not use my right hand for several months. But suggestively i will said that M820 is a fewer less drag (very few) than EP801. i will not contest if somebody said that the 2 are free. In any case, i do not think that could be an discus subject or justified to chose one more the other

get well soon friend

 

[Kiwi_Stu]

I own two Bafang M820 48V ebikes.
1 - CEF50 (mine), firmware CRX30PC4812E102006.1.
2 - CEF55 (wife), firmware CRX304313E102004.5.
Now, let's look at the differences in practice. I find "1" to be conservative, with standard acceleration and a power cut below 22%, very smooth when turning off the engine, to the point that drag is present. I believe it's psychological because it's off and heavy. I notice that the engine pulls for about 2 seconds after stopping pedaling with the engine running.
Now, let's talk about "2." It delivers more power, a battery cut below 10%, adjusted for maximum acceleration, and the clutch automatically turns off when stopping pedaling with the engine running, and with the engine off, there's no apparent drag. She believes I made adjustments due to the different profiles between my wife and I, and that the M510 would have been a better choice for her.
For people who cycle touring, if you use the bike in eco/trail mode to compensate for the weight of luggage without losing the feeling of pedaling, the m820 motor is perfect. I am an XCM cyclist and do 100km rides with 2000m of elevation, alternating between the motor and legs, the motor on climbs and legs at other times, the motor is perfect.

Hi there, i see you comment that for your wife's bike a different firmware is installed with lower voltage cutoff (at 10%), how come you haven't also decided to use this firmware version and get 10% more battery usage before the motor turns off?
Also what's your experience with M820 overheating as I've read people experiencing this on long climbs and the motor reducing power support?
Thanks
Stu

 

[lkdoido]

Hi there, i see you comment that for your wife's bike a different firmware is installed with lower voltage cutoff (at 10%), how come you haven't also decided to use this firmware version and get 10% more battery usage before the motor turns off?
Also what's your experience with M820 overheating as I've read people experiencing this on long climbs and the motor reducing power support?
Thanks
Stu

My wife (CEF55) and I (CEF50) have different riding styles; she uses Sport+ and Boost, while I use Eco and Trail. Her rides are up to 40km with 600m of elevation gain, while I prefer to do twice that. The other day I rode with the 43v firmware and noticed it heated up a bit more than the 48v for the same power/assistance settings. I only recently found the same firmware I'm using now, and now I can test it and revert to the previous version if needed; this was the reason I hadn't changed my firmware. Regarding the two bikes, I liked the CEF55 better; it's more stable and agile.

Cef50 48v: https://strava.app.link/AynLQ9iLvYb
Cef55 43v: https://strava.app.link/31YpVSdLvYb

Youtube cef55 43v:

 

[Kiwi_Stu]

My wife (CEF55) and I (CEF50) have different riding styles; she uses Sport+ and Boost, while I use Eco and Trail. Her rides are up to 40km with 600m of elevation gain, while I prefer to do twice that. The other day I rode with the 43v firmware and noticed it heated up a bit more than the 48v for the same power/assistance settings. I only recently found the same firmware I'm using now, and now I can test it and revert to the previous version if needed; this was the reason I hadn't changed my firmware. Regarding the two bikes, I liked the CEF55 better; it's more stable and agile.

Thanks for the info, I've ordered a CEF50 with M820 and 835wh battery (plus Besst tool) so will have to wait until it arrives to check the firmware and setup options - do you have a link to where we can find and download different firmware versions?

 

[Kiwi_Stu]

Thanks for the info, I've ordered a CEF50 with M820 and 835wh battery (plus Besst tool) so will have to wait until it arrives to check the firmware and setup options - do you have a link to where we can find and download different firmware versions?

I found this thread with several firmware versions so will download them to have ready, is

Bafang M820 Firmware thread

I wonder how they count that. Even with 48V battery and 43V firmware I get maximum 650W. So with cadens 80 that is still only 77Nm.

www.emtbforums.com

 

[lkdoido]

I found this thread with several firmware versions so will download them to have ready, is

Bafang M820 Firmware thread

I wonder how they count that. Even with 48V battery and 43V firmware I get maximum 650W. So with cadens 80 that is still only 77Nm.

www.emtbforums.com

Post in thread 'Bafang M820 Firmware thread' Bafang M820 Firmware thread

 

[Jil]

soory i am currently broken, one mtorcycle cut me in 2 at my last road exit and i can not use my right hand for several months. But suggestively i will said that M820 is a fewer less drag (very few) than EP801. i will not contest if somebody said that the 2 are free. In any case, i do not think that could be an discus subject or justified to chose one more the other

Merci Patdam ! Et je te souhaite bon rétablissement

 

[Jil]

soory i am currently broken, one mtorcycle cut me in 2 at my last road exit and i can not use my right hand for several months. But suggestively i will said that M820 is a fewer less drag (very few) than EP801. i will not contest if somebody said that the 2 are free. In any case, i do not think that could be an discus subject or justified to chose one more the other

So, less drag than the EP801 - which already has almost no drag - that’s very good! It means the M820 is a motor that’s nice to pedal past the speed cut-off (or without a battery). Good to know!