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

calvintys

Active member
Sep 12, 2023
250
251
Malaysia

ssl

New Member
Aug 27, 2024
39
13
Switzerland
Just found this amazing item on AliExpress. Check it out!
MYR995.76 | San-yo3500mAh Bottle EBike Battery 48V 36V 7Ah 10.5Ah 9Ah Electric Bicycle18650 Batteries Pack for Bafang 250W350W500W Motor Kit
You have one of these and they work well? how is charging and decharging working? any pics?
 

souftosouf

New Member
May 4, 2024
23
2
Marseille - France
Do you guys had issues with the bolt mouting the battery ? i cant screw them to full length

Same issue with the motor cover
Another question on top of this : how did you manage the cable for the dropper post ?

Mine is stuck between the frame and the motor and i cant move it freely whenever i want to raise or lower the seat post
 
Last edited:

Yozha

Member
Sep 10, 2023
64
38
Kazakhstan
Another question on top of this : how did you manage the cable for the dropper post ?

Mine is stuck between the frame and the motor and i cant move it freely whenever i want to raise or lower the seat post
I left a spare cable above the motor on the dropper post side. It moves normally 2-3 cm. Enough to adjust the height for me and my son.
 

ssl

New Member
Aug 27, 2024
39
13
Switzerland
Super frustrated and seriously regretting not just spending more and buying a Bosch EMTB. I've triple checked that everything is plugged in correctly and the motor/display simply will not power on. I can get the blue power button that's on the frame to turn on but that's it. I've reached out to Jean and let her know that I am having problems but even if she is cool enough to send me new electronics, it's going to take an additional month on what has already turned into a 2+ month build.

-Cable that connects the battery to the charging port is plugged in. Cable that connects the motor to the battery is plugged in. Cable that connects the display to the motor is plugged in. Cable that connects the speed sensor to the motor is plugged in. Everything else is wrapped/unused. All connections are snug. Nothing. Piece of crap appears to be dead on arrival. Nice $2000 paperweight.
Battery is charged? :)
 

patdam

Well-known member
Jan 17, 2019
902
601
france
Anyone got and uses Bafang DP E171 smart button display? And where to get them from?
I had used it on the handlebar for the beauty of DIY :geek:. Replaced. To be honest DPC245 is more efficient and easy to use
DSCF2156.JPG
 

gkparker85

New Member
Aug 15, 2024
11
6
Orem, UT
Potential buyers beware. My CEF50 appears to be dead-on-arrival. The blue power button on my frame will turn on, but the motor/display will not. Everything is plugged in correctly/snugly. I bought it through Jean on Alibaba and have reached out to her regarding the issue. I haven't heard back, but even if she sends replacement hardware, I'm looking at a 1+ month resolution in addition to the 7 weeks I've already spent waiting to build this bike. I'm extremely disappointed and would not purchase this type of thing from China again given my experience. Hoping I can return the frame altogether at this point honestly.

-Plugged in charger for 8 hours.
-Made sure cable that connects the battery to both the charging port and the motor is plugged in tight at all terminals.
-Made sure that the cable connecting the speed sensor to the motor is plugged in tight
-Made sure the cable from the motor to the display is plugged in to both the motor and the display snugly.
-Power button on frame will light up but no power is being sent to the motor/display.

No idea if the it's the battery, the motor, or one of the connector cables causing the problem. The power button on the
thumb control unit also does nothing.

IMG_1929.jpeg
 

patdam

Well-known member
Jan 17, 2019
902
601
france
Potential buyers beware. My CEF50 appears to be dead-on-arrival. The blue power button on my frame will turn on, but the motor/display will not. Everything is plugged in correctly/snugly. I bought it through Jean on Alibaba and have reached out to her regarding the issue. I haven't heard back, but even if she sends replacement hardware, I'm looking at a 1+ month resolution in addition to the 7 weeks I've already spent waiting to build this bike. I'm extremely disappointed and would not purchase this type of thing from China again given my experience. Hoping I can return the frame altogether at this point honestly.

-Plugged in charger for 8 hours.
-Made sure cable that connects the battery to both the charging port and the motor is plugged in tight at all terminals.
-Made sure that the cable connecting the speed sensor to the motor is plugged in tight
-Made sure the cable from the motor to the display is plugged in to both the motor and the display snugly.
-Power button on frame will light up but no power is being sent to the motor/display.

No idea if the it's the battery, the motor, or one of the connector cables causing the problem. The power button on the
thumb control unit also does nothing.

View attachment 146039
1) Purchasing in china aren't submited at the same rules than EU or other western country. If you don't want to subit an nervous breakdown Don't hope to return your purchase and expect refund.

2) DIY bike is different experiency than purchase complete brand bike on store. That need competencies in mechanical, electricitad, software, etc... and the taste to do this.

3) build an DIY bike for economical raison is an wrong motivation and This is the assurance of great disappointment..

My recomendations. find somebody near your locations who have competencies to identified the cause of fail, set aside money to paied it and purchasing spare parts necessary and pray.

Good luck to solve your problem (problems ?)
 

calvintys

Active member
Sep 12, 2023
250
251
Malaysia
Potential buyers beware. My CEF50 appears to be dead-on-arrival. The blue power button on my frame will turn on, but the motor/display will not. Everything is plugged in correctly/snugly. I bought it through Jean on Alibaba and have reached out to her regarding the issue. I haven't heard back, but even if she sends replacement hardware, I'm looking at a 1+ month resolution in addition to the 7 weeks I've already spent waiting to build this bike. I'm extremely disappointed and would not purchase this type of thing from China again given my experience. Hoping I can return the frame altogether at this point honestly.

-Plugged in charger for 8 hours.
-Made sure cable that connects the battery to both the charging port and the motor is plugged in tight at all terminals.
-Made sure that the cable connecting the speed sensor to the motor is plugged in tight
-Made sure the cable from the motor to the display is plugged in to both the motor and the display snugly.
-Power button on frame will light up but no power is being sent to the motor/display.

No idea if the it's the battery, the motor, or one of the connector cables causing the problem. The power button on the
thumb control unit also does nothing.

View attachment 146039
have you try pull out your motor and controller cable from both side and push it back in. It happen to me once and i try a few time and it solve my problem.
 

souftosouf

New Member
May 4, 2024
23
2
Marseille - France
Potential buyers beware. My CEF50 appears to be dead-on-arrival. The blue power button on my frame will turn on, but the motor/display will not. Everything is plugged in correctly/snugly. I bought it through Jean on Alibaba and have reached out to her regarding the issue. I haven't heard back, but even if she sends replacement hardware, I'm looking at a 1+ month resolution in addition to the 7 weeks I've already spent waiting to build this bike. I'm extremely disappointed and would not purchase this type of thing from China again given my experience. Hoping I can return the frame altogether at this point honestly.

-Plugged in charger for 8 hours.
-Made sure cable that connects the battery to both the charging port and the motor is plugged in tight at all terminals.
-Made sure that the cable connecting the speed sensor to the motor is plugged in tight
-Made sure the cable from the motor to the display is plugged in to both the motor and the display snugly.
-Power button on frame will light up but no power is being sent to the motor/display.

No idea if the it's the battery, the motor, or one of the connector cables causing the problem. The power button on the
thumb control unit also does nothing.

View attachment 146039
what HMI do you have E181 or C245 ? have you tried walk assist to see if it works ?


Do you have flashing lights with the power button on frame ?

Can you measure the battery voltage with a multimeter ?

Show us your setup ?
 

PaulH

New Member
Apr 23, 2024
29
21
Dallas, Texas USA
1) Purchasing in china aren't submited at the same rules than EU or other western country. If you don't want to subit an nervous breakdown Don't hope to return your purchase and expect refund.

2) DIY bike is different experiency than purchase complete brand bike on store. That need competencies in mechanical, electricitad, software, etc... and the taste to do this.

3) build an DIY bike for economical raison is an wrong motivation and This is the assurance of great disappointment..

My recomendations. find somebody near your locations who have competencies to identified the cause of fail, set aside money to paied it and purchasing spare parts necessary and pray.

Good luck to solve your problem (problems ?)
"2) DIY bike is different experiency than purchase complete brand bike on store. That need competencies in mechanical, electricitad, software, etc... and the taste to do this." <---- This makes us sound kindda COOL :)
 

TCFlowClyde

Active member
Feb 26, 2022
1,341
866
Mesa, AZ
Potential buyers beware. My CEF50 appears to be dead-on-arrival. The blue power button on my frame will turn on, but the motor/display will not. Everything is plugged in correctly/snugly. I bought it through Jean on Alibaba and have reached out to her regarding the issue. I haven't heard back, but even if she sends replacement hardware, I'm looking at a 1+ month resolution in addition to the 7 weeks I've already spent waiting to build this bike. I'm extremely disappointed and would not purchase this type of thing from China again given my experience. Hoping I can return the frame altogether at this point honestly.

-Plugged in charger for 8 hours.
-Made sure cable that connects the battery to both the charging port and the motor is plugged in tight at all terminals.
-Made sure that the cable connecting the speed sensor to the motor is plugged in tight
-Made sure the cable from the motor to the display is plugged in to both the motor and the display snugly.
-Power button on frame will light up but no power is being sent to the motor/display.

No idea if the it's the battery, the motor, or one of the connector cables causing the problem. The power button on the
thumb control unit also does nothing.

View attachment 146039
Looks like it's plugged into the motor correctly. If it's getting juice to the frame power button it still could be the battery itself or the connections are just bad wires as you're deducing. Sounds definitely frustrating. 😔

While it could be the Bafang M820 motor itself, I'd argue that they're are generally reliable. Their QC is on par with Bose, Bosch, Shimano. But it's possible.

Since most of us have SZZS (3rd party) batteries, its more likely the battery and its associated wires harness. I'd keep after Jean on that angle. I've had two separate frame warranty issues that SZZS did replace, but it took persistence with a lot of photos and video evidence, with diplomacy, and then finally threats of refund request to rectify it. It absolutely drains once patience.

The battery takes longer to remedy due to logistics and slower overseas container boat shipping.😝 Fortunately, the frame stuff took just 2-3 weeks by air. So, 6-8 weeks to your door, if they warranty replace it for you by sea.

Overall, I'd pursue battery + wire harness. It's sucks, but the CEF50 really has turned out to be a surprisingly nice enduro build... I luv it 🥰. It's my preferred e-mtb to ride solo. So, the hassle has been worth it for me.
 

masahirov

New Member
Jan 24, 2024
23
17
tokyo japan
Potential buyers beware. My CEF50 appears to be dead-on-arrival. The blue power button on my frame will turn on, but the motor/display will not. Everything is plugged in correctly/snugly. I bought it through Jean on Alibaba and have reached out to her regarding the issue. I haven't heard back, but even if she sends replacement hardware, I'm looking at a 1+ month resolution in addition to the 7 weeks I've already spent waiting to build this bike. I'm extremely disappointed and would not purchase this type of thing from China again given my experience. Hoping I can return the frame altogether at this point honestly.

-Plugged in charger for 8 hours.
-Made sure cable that connects the battery to both the charging port and the motor is plugged in tight at all terminals.
-Made sure that the cable connecting the speed sensor to the motor is plugged in tight
-Made sure the cable from the motor to the display is plugged in to both the motor and the display snugly.
-Power button on frame will light up but no power is being sent to the motor/display.

No idea if the it's the battery, the motor, or one of the connector cables causing the problem. The power button on the
thumb control unit also does nothing.

View attachment 146039
Hello gkparker85, did you solve the problem? The cable that goes to the display may not connect if it is not inserted firmly, so I think it's better to insert it firmly again. Also, I don't see many cables with power buttons on this forum, so the cable itself may not be compatible. I think the cable that came with my frame kit was BF EB BUS-1T2. I hope the problem is solved soon.
1725093701785.png

BAFANG Central Motor Main Line Display Cable EB-BUS 1T2 1T3 1T4 M500 M600 M510 M820 Throttle Cable 6V Front Light Cable - AliExpress 18
 

PaulH

New Member
Apr 23, 2024
29
21
Dallas, Texas USA
Hello gkparker85, did you solve the problem? The cable that goes to the display may not connect if it is not inserted firmly, so I think it's better to insert it firmly again. Also, I don't see many cables with power buttons on this forum, so the cable itself may not be compatible. I think the cable that came with my frame kit was BF EB BUS-1T2. I hope the problem is solved soon.
View attachment 146091
BAFANG Central Motor Main Line Display Cable EB-BUS 1T2 1T3 1T4 M500 M600 M510 M820 Throttle Cable 6V Front Light Cable - AliExpress 18
It3, but I suspect the it2 would work with a non-canbus battery, i.e. DIY.
 

gkparker85

New Member
Aug 15, 2024
11
6
Orem, UT
Thanks for all the replies offering to help me troubleshoot my problem. I finally managed to get the display to turn on, but now I'm running into a whole new issue. Whenever the bike is pointed downhill, the headlight icon turns on and the display goes dim. Pointing it back uphill causes the icon to turn off and the display to get bright again. The unused accessory cable for a light is completely unused - dangling free with the terminals not touching anything while this happens.
 

Joshack92

New Member
Aug 27, 2024
6
0
Uk
Thanks for all the replies offering to help me troubleshoot my problem. I finally managed to get the display to turn on, but now I'm running into a whole new issue. Whenever the bike is pointed downhill, the headlight icon turns on and the display goes dim. Pointing it back uphill causes the icon to turn off and the display to get bright again. The unused accessory cable for a light is completely unused - dangling free with the terminals not touching anything while this happens.
Sounds like a loose plug or something along those lines. Check the connections
 

Rusty-spokes

New Member
Aug 20, 2024
7
10
Canada
Thanks for all the replies offering to help me troubleshoot my problem. I finally managed to get the display to turn on, but now I'm running into a whole new issue. Whenever the bike is pointed downhill, the headlight icon turns on and the display goes dim. Pointing it back uphill causes the icon to turn off and the display to get bright again. The unused accessory cable for a light is completely unused - dangling free with the terminals not touching anything while this happens.
I had this and it’s an auto dim, the light sensor is just sensing different light. Go into display settings and go to AL sensitivity and select OFF
 

MrFixit

Member
Mar 3, 2023
75
40
UK
Anyone have any trouble with their electronics not working? I finally got all my cables routed and reinstalled the motor. Made sure all 3 plugs that go into the motor are nice and snug. Power button on frame will light up but motor and display will not power on. Wondering if I got a dud or if I am doing something wrong?
I feel your pain. My original motor never worked from out off the box, it had to be returned, the second one worked fine until recently. Have you tried to switch your motor on with the charging cable plugged in? Mine no longer switches on, but it sometimes does with the charger connected! I think mine has a connection issue, see here; Bafang m820 I hope you get sorted.
 

brbr

Active member
Dec 28, 2022
529
270
France
I feel your pain. My original motor never worked from out off the box, it had to be returned, the second one worked fine until recently. Have you tried to switch your motor on with the charging cable plugged in? Mine no longer switches on, but it sometimes does with the charger connected! I think mine has a connection issue, see here; Bafang m820 I hope you get sorted.
check around here SZZS specific CEF50-main thread (initial builds and troubleshooting related only) :)
 

ssl

New Member
Aug 27, 2024
39
13
Switzerland
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.
You update firmwae with Bafang Go app or need Bestt Tool?
 

ssl

New Member
Aug 27, 2024
39
13
Switzerland
Did anyone try the following chainguide / rock guard?
Might it fit the M820?

View attachment 138068

Or Maybe this chain guide:

Will try this one Ztto Fahrradkette führung iscg03 iscg05 bb Kettens chutz mtb dh am Ketten führung Kettenblatt 32-38t 1x System Kettenrad - AliExpress 18
 

voigtkampff

Member
Oct 18, 2023
97
97
Poland
You update firmwae with Bafang Go app or need Bestt Tool?
I use BESST. I have 48V system, which is originally 36V engine reprogrammed by SZZT to 48V firmware, so Go app will identify it as 36V using serial number and will update FW to 36V version. This will immediately cause engine error (too high battery voltage) requiring to manually flash 48V firmware with BESST. So it seems like manual upgrade with BESST is the only option for me.
 

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