SZZS specific CEF50-main thread (initial builds and troubleshooting related only)

LAnton

Active member
May 12, 2022
550
458
Russia
Oh, so there are people who have the same problem as me. My headset can be easily attached and detached by hand.

Naturally, noise and vibration come from the head cup, but we have been able to reduce this considerably by placing a piece of paper between the head tube and the head cup.

As this was my first e-bike I was a bit worried about the motor and battery, but I never expected to end up having trouble with the frame.
This is the fate of B testers. But he rides very well :)
 

8Grunf

New Member
Jan 29, 2024
24
67
Italia
Good morning everyone, I'm writing from the north east of Italy.
First I want to thank you for inspiring me in the creation of this beautiful bike, this is not the first build, as I already have experience with the Dengfu E09 and E10 frames.

I present to you with great pleasure the final result:


1712666249939.jpg


1712666177867.jpg


1712570993052.jpg


The weight of the bike is 18.3 kg with 480wh 48v battery

Daniele.
 

mike_kelly

Well-known member
Subscriber
Aug 11, 2022
929
759
US
The m620 is an anomaly, not the norm. Its sales numbers arent even a blip in the grand scheme of things. Its readily accepted that EP8 and bosch cx motors are both full power 50+ lb ebikes at 85nm of torque. Ready any ebike reviews that reference this.

Ive never said anything about operating outside designer operating conditions. Ive only ever said 48v runs significantly cooler than 36v and showed you the math why. Are you saying you still disagree with the math?

And straight quoted from your post, the Bafang engineers dont recommend long durations in boost. Why? It is thermally limited by the heatsinks ability to remove heat. What does that translate to in real world situations? You can probably ride longer before you hit thermal limit in boost.

Running cooler is never a bad thing with electronics. It absolutely lowers failure rates.
I will give you that if you are riding motor out of the design range then 48v is going to allow you to run more into the red zone. The M820 is a lightweight low power motor in anybody's book. Every other motor in the Bafang range has more power. The BBSHD is a 750w motor. It is all a matter of perspective.
I maintain that if you are using the bike the way Bafang designed it then you are not going to notice the difference.
 

Bengy22

Member
Aug 25, 2022
125
80
USA
This is why I stand by my statements regarding 48v running way cooler than 36v and will lead to better reliability and longevity of components. This is a full size motor packaged in a low power casing. The math doesnt lie. Say at 500w, the 48v system has roughly 78% less heat.
Thought I would chime in to confirm this. My street commuter build is a bbshd with an aftermarket controller for easy tuning and more power. On 52v I would hit thermal rollback on my bike almost every ride. I built myself a 72v battery early this year for more range and power. Now I'm running the same amps (or roughly a 40% increase in watts!) and I've only hit that rollback a few times. The temp difference is massive, with a huge decrease going to 72v. Speak to anyone in the diy ebike community around going higher voltage and they will tell you the same thing.

I find it interesting bafang doesn't suggest a higher wh battery due to concerns about overheating, when on the hardware side they could have just installed a temp sensor and had power rollback when needed. It really should have one anyway (assuming it doesn't). I would love to hear from someone who's tested both a 36v and 48v m820 though. I'm actually a little confused about how bafang can claim the 85nm of torque for it even with the higher voltage offering which we know is the same hardware just different software with reduced peak amps. Seems like only the 36v system would peak that high. But this would directly affect torque produced, but shift the rpms to higher as well. One could just gear the bike slightly lower to compensate for this but then the cadence / where the power is would be different. Seems like the 36v could be the most punchy
 

TCFlowClyde

Active member
Feb 26, 2022
1,335
863
Mesa, AZ
I would love to hear from someone who's tested both a 36v and 48v m820 though.
Sounds like a YouTube Bafang challenge for Neeko to me. 😎

Hey Bafang, ship Neeko DeVinchi both motors with appropriate batteries please.

Also, Neeko, can you some how get a infrared heat sensory set up on a drone too...you know in order to follow you up a climb for peak output at night?😉

Now that actually would be seriously cool!🍻😁😀
 
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92se-r

New Member
Dec 23, 2023
161
60
United states
Sounds like a YouTube Bafang challenge for Neeko to me. 😎

Hey Bafang, ship Neeko DeVinchi both motors with appropriate batteries please.

Also, Neeko, can you some how get a infrared heat sensory set up on a drone too...you know in order to follow you up a climb for peak output at night?😉

Now that actually would be seriously cool!🍻😁😀
Im in socal and i have an ir temp gun. Come visit
 

mike_kelly

Well-known member
Subscriber
Aug 11, 2022
929
759
US
Good morning everyone, I'm writing from the north east of Italy.
First I want to thank you for inspiring me in the creation of this beautiful bike, this is not the first build, as I already have experience with the Dengfu E09 and E10 frames.

I present to you with great pleasure the final result:

View attachment 137902

The weight of the bike is 18.3 kg with 480wh 48v battery

Daniele.
Friuli-Venezia Giulia or Alto Adige?
 

TCFlowClyde

Active member
Feb 26, 2022
1,335
863
Mesa, AZ
Im in socal and i have an ir temp gun. Come visit
Hells yeah!🤟 That would be an awesome video adventure opportunity in some great weather. Could test it doing a stout shorter climb at Whiting Ranch/Laguna Hills, or bigger Santiago Canyon, or even the ultimate climb up the big San Juan trail epic all Orange County rides. Don't forget another lung buster Noble Canyon "near" San Diego. (Shoot, I'm getting homesick.)

Point being, it would be a fun test in some challenging terrain. It would give Neeko's channel a wider viewer audience. Maybe, get Bafang sponsorship for Neeko (pay of the trip) to showcase the M820 riding in the huge market economy of California. 💸
 

ficorama

Active member
Oct 9, 2021
350
301
Croatia
today was the first ride. the bike is great, the engine is amazing. I think the m820 is the best Bafang motor. enough power, minimal battery consumption.
I rode mostly T and S, S+ and for the test B a few meters on the climb. enough power on the climbs, only in B mode did the E09 drop out, maybe the firmware would solve that.

the engine has very good power modulation, it is not as smooth as Brose, Giant, Bosch, but it is excellent.

since I have an 11s 3p 17.5ah battery, on the first ride I had 100% left. means that the voltage did not drop below 42v during the 900-meter ascent (full battery before driving at 46.2v)

20240409_174444.jpg Screenshot_20240409_195439_Strava.jpg
 

ficorama

Active member
Oct 9, 2021
350
301
Croatia
On the factory 36v battery, is it a 10s or 11s? I am wondering if it is power limiting you in boost. What bms do you have?
factory 36v is 10s. and it seems to me that it is the engine protection or maybe an error in the firmware. I'll try a few things and we'll see.
 

voigtkampff

Member
Oct 18, 2023
96
96
Poland
today was the first ride. the bike is great, the engine is amazing. I think the m820 is the best Bafang motor. enough power, minimal battery consumption.
I rode mostly T and S, S+ and for the test B a few meters on the climb. enough power on the climbs, only in B mode did the E09 drop out, maybe the firmware would solve that.

the engine has very good power modulation, it is not as smooth as Brose, Giant, Bosch, but it is excellent.

since I have an 11s 3p 17.5ah battery, on the first ride I had 100% left. means that the voltage did not drop below 42v during the 900-meter ascent (full battery before driving at 46.2v)
I also experienced E09 2 times so far. Both happened after steep ascent, 2nd time in B mode, soon after displayed battery level drop occured. I've checked a moment ago that upgrading firmware to version CRX30PC4813E102004.3 I got from Jean today didn't solve the battery level issue, dunno if this will help with E09. Bafang docs says "engine phase error, replace the engine". In my case E09 was displayed for like 1-2s on the screen and disappeared without my intervention, engine works like nothing happened.
 

ficorama

Active member
Oct 9, 2021
350
301
Croatia
I also experienced E09 2 times so far. Both happened after steep ascent, 2nd time in B mode, soon after displayed battery level drop occured. I've checked a moment ago that upgrading firmware to version CRX30PC4813E102004.3 I got from Jean today didn't solve the battery level issue, dunno if this will help with E09. Bafang docs says "engine phase error, replace the engine". In my case E09 was displayed for like 1-2s on the screen and disappeared without my intervention, engine works like nothing happened.
so do I, it shows an error and after a few seconds it disappears and the engine starts working. probably some protection. did you ask about that mistake, where did you buy it?
My FW CRX30PC3615E102003.3
 

voigtkampff

Member
Oct 18, 2023
96
96
Poland
so do I, it shows an error and after a few seconds it disappears and the engine starts working. probably some protection. did you ask about that mistake, where did you buy it?
My FW CRX30PC3615E102003.3
I have ongoing discussion about this issue with Jean, she forwarded this to technical staff and I'm awaiting their response. I need yet to see if the firmware she sent helped with E09, so far I didn't have a chance to put this into action.
 

ficorama

Active member
Oct 9, 2021
350
301
Croatia
I have ongoing discussion about this issue with Jean, she forwarded this to technical staff and I'm awaiting their response. I need yet to see if the firmware she sent helped with E09, so far I didn't have a chance to put this into action.
please let me know if the new FW helped. thank you
 

LAnton

Active member
May 12, 2022
550
458
Russia
Ride on firmware 43V - CRX30PC4313E102001 3_eMTB_230317, battery 48V 20A (21700 4700ma = 18.8A). There were no mistakes. The motor is in Boost mode 40 degrees. The M510 couldn't overtake me on a steep climb

WhatsApp Image 2024-04-10 at 09.29.05.jpeg
 
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TCFlowClyde

Active member
Feb 26, 2022
1,335
863
Mesa, AZ
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calvintys

Active member
Sep 12, 2023
250
250
Malaysia

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