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

spokémon

Member
Apr 4, 2023
191
99
Australia
TBH I don't know what to expect here, from the SZCT drawings it would look like the seat tube is quite short compared to my other bikes so I was hoping I could fit at least 175mm, but I might be proven wrong. I guess my legs are quite regular.

Looking at the technical drawing from SZCT it would seem that the seat tube starts to bend backwards at sth like 22.5cm of insert on M-sized frame

CEF50 seattube length is the same as other Size M modern bikes @410mm (Transition Relay, Trek Fuel Exe) generally come standard with 150mm dropper.
I would suggest on your current bikes, measure the length from centre crank spindle to centre seatpost rail.
From there, you can calculate and get a better idea on what you need. Seattube length + dropper post from collar to rail.
 

brbr

Active member
Dec 28, 2022
529
270
France
Hey @Neeko DeVinchi , after reading your posts, I understand the frame would be compatible with a 1.8" tapered fork ? I have a LCE930, which has a straight head tube, do you think it's compatible as well, with what kind of headset?
 

Neeko DeVinchi

E*POWAH Elite World Champion
Dec 31, 2020
1,033
1,376
UK
Hey @Neeko DeVinchi , after reading your posts, I understand the frame would be compatible with a 1.8" tapered fork ? I have a LCE930, which has a straight head tube, do you think it's compatible as well, with what kind of headset?
No. The LCE930's headtube Is designed for a traditional 1.5 tapered fork. The headset requirements for that frame are zs56 upper and lower.
20230916_173306.jpg

Similar to the Dengfu E55.
The above link should take you to a thread which should explain further👍🏿
 

voigtkampff

Member
Oct 18, 2023
97
97
Poland
CEF50 seattube length is the same as other Size M modern bikes @410mm (Transition Relay, Trek Fuel Exe) generally come standard with 150mm dropper.
I would suggest on your current bikes, measure the length from centre crank spindle to centre seatpost rail.
From there, you can calculate and get a better idea on what you need. Seattube length + dropper post from collar to rail.
Indeed you were right with 150mm. I've measured my current setup to be 630mm from crank spindle to seatpost rail + 175mm of crank arm length, this gives 805mm of leg reach, now when I subtract 410mm of new seat tube length and 165mm of new crank arm I get 230mm from seatpost clamp to saddle rails. Entering this into Dropper Post Length Calculator with 224mm of insertion length yields 150mm travel with OneUp, the same with RF Turbine R, PNW Loam and KS Integra.
 

Myalteregohamish

Active member
Jan 4, 2023
294
240
Vancouver, WA
Hey guys when riding with my super fit buddy on his FF Levo I’m developing a case of range anxiety with my 720wh. Are there any options you can think of for increasing range up to 900wh+?
 

TCFlowClyde

Active member
Feb 26, 2022
1,347
870
Mesa, AZ
I know that’s been discussed. And I’ve never done something like that. Is there a cookbook i could follow the build one. With the right BMS for it?
Maybe. Neeko might adapt Mike Kelly's recommended 3rd party water bottle battery extender protocol for the lesser smartness peeps (like me) with a step-by-step build video.🤞
 

mike_kelly

Well-known member
Subscriber
Aug 11, 2022
941
773
US
I used a pre-made bottle battery from Aliexpress. Good quality battery with it's own BMS inside so nothing to do. But to use ANY external you have to have a connector on the frame to get the power inside. That is decidedly DIY. It is not hard if you can use a soldering iron. The connector I found is not pretty and it is big but it works well, is water proof and I have been using the bottle batteries for months because my inside batteries were damaged in shipment originally. I would not like to use my bike now without the bottle battery as a range extender option.
With both batteries you need a diode to prevent the external battery from affecting the internal and vice-versa.
I won't create a step by step because dealing with large capacity LIthium batteries like these should not be attempted if you don't have experience. There is no way to "turn off the battery" when you are making one or hacking on up. So one short circuit and you could have a fire. It is not a big deal if you have done electrical/electronic work and used a soldering iron to wire connectors before but I don't want to be responsible for someone burning down their house.
Here again is my over view. Just get a local friend who has experience to help.
My connector fits right in the hole where the old connector went to ovoid drilling out the frame.
 

Neeko DeVinchi

E*POWAH Elite World Champion
Dec 31, 2020
1,033
1,376
UK
Maybe. Neeko might adapt Mike Kelly's recommended 3rd party water bottle battery extender protocol for the lesser smartness peeps (like me) with a step-by-step build video.🤞
I've given this some thought.
The issues which I fave is that more and more ebike riders are expressing concern for ebike battery fires.
20231025_094037.jpg

Even I've had to take this onboard in terms of addressing the safety aspect. Which is why I opted to implement the entire Bafang M820 system. As apose to using the motor and a third party battery.
20231019_152534.jpg

Then theirs the frame and how one could neatly implement a range extender without having cables protruding, without looking out of place (not looking like a DIY job).
20230929_140613.jpg

The holes on the to side of the downtube are designed to hold the battery mount in place (as well as the attachment point for the bottle cage).
20230929_140807.jpg

So the only logical point would be to use the charge port (again, for a neat non-diy looking purpose built range extender).

Which leaves me contemplating the following:-
1. Should Bafang impliment an official range extender battery which coincides with their plug-n-play ethos (which would include a new firmware update to allow the system to recognise more than one battery being used), Shenzhen Zhaosheng would probably make a revised version of the CEF50 or possibly design a new frame to better facilitate the new range extender. Or,
2. If Bafang opts not to implement a range extender, then a third party company (by default) would need to build a range extender of a higher voltage than the main battery. However, it wouldn't work like a typical range extender. Moreso, it would work like a portable battery charger which would fuel the main battery. But the issue for designing such a range extender battery would mean that discharge rate 'could' exceed the recharge rate. Which would then lead to overheating. And then theirs,
3. Safety. Bafang have made it clear that the choice of using 2amp chargers for their batteries (36v and 43v) was intentional, in an effort to maximise battery lifespan and reduce any malfunctions throughout the charging process. Coupled with the fact that the M820 uses a xt30 connector (to reduce the amps its able to pull from the motor. Any range extender designed would need a bms to 'STRICTLY' administer current at specific times, in an effort to not put unnecessary load on either the main battery, existing wire harness and the controller for the M820 motor.

Don't get me wrong, I think about this often. Which is why I'll keep my ears to the ground and report anything and everything I learn.

But as for simply retrofitting a random bottle battery to the battery (or retrofitting a xt30 splitter to the main wire harness and running a bottle battery separately), I think we can all do better imo.
IMG_20190318_092054.jpg

We've all come along way from diy ebikes of old, where random wires and cables would protrude from frames (looking like a bodge). Personally, I don't want to spoil the look of my CEF50 with random cables.
20231028_150041.jpg

Unless a range extender can be implement and its a clean and safe integration, then I'm not interested in ruining the look of my own.
Sorry if that's not what you wanted to hear @TCFlowClyde 👍🏿
 

TCFlowClyde

Active member
Feb 26, 2022
1,347
870
Mesa, AZ
I've given this some thought.
The issues which I fave is that more and more ebike riders are expressing concern for ebike battery fires.
View attachment 130470
Even I've had to take this onboard in terms of addressing the safety aspect. Which is why I opted to implement the entire Bafang M820 system. As apose to using the motor and a third party battery.
View attachment 130471
Then theirs the frame and how one could neatly implement a range extender without having cables protruding, without looking out of place (not looking like a DIY job).
View attachment 130477
The holes on the to side of the downtube are designed to hold the battery mount in place (as well as the attachment point for the bottle cage). View attachment 130478
So the only logical point would be to use the charge port (again, for a neat non-diy looking purpose built range extender).

Which leaves me contemplating the following:-
1. Should Bafang impliment an official range extender battery which coincides with their plug-n-play ethos (which would include a new firmware update to allow the system to recognise more than one battery being used), Shenzhen Zhaosheng would probably make a revised version of the CEF50 or possibly design a new frame to better facilitate the new range extender. Or,
2. If Bafang opts not to implement a range extender, then a third party company (by default) would need to build a range extender of a higher voltage than the main battery. However, it wouldn't work like a typical range extender. Moreso, it would work like a portable battery charger which would fuel the main battery. But the issue for designing such a range extender battery would mean that discharge rate 'could' exceed the recharge rate. Which would then lead to overheating. And then theirs,
3. Safety. Bafang have made it clear that the choice of using 2amp chargers for their batteries (36v and 43v) was intentional, in an effort to maximise battery lifespan and reduce any malfunctions throughout the charging process. Coupled with the fact that the M820 uses a xt30 connector (to reduce the amps its able to pull from the motor. Any range extender designed would need a bms to 'STRICTLY' administer current at specific times, in an effort to not put unnecessary load on either the main battery, existing wire harness and the controller for the M820 motor.

Don't get me wrong, I think about this often. Which is why I'll keep my ears to the ground and report anything and everything I learn.

But as for simply retrofitting a random bottle battery to the battery (or retrofitting a xt30 splitter to the main wire harness and running a bottle battery separately), I think we can all do better imo.
View attachment 130480
We've all come along way from diy ebikes of old, where random wires and cables would protrude from frames (looking like a bodge). Personally, I don't want to spoil the look of my CEF50 with random cables.
View attachment 130482
Unless a range extender can be implement and its a clean and safe integration, then I'm not interested in ruining the look of my own.
Sorry if that's not what you wanted to hear @TCFlowClyde 👍🏿
Oh man, now I gonna have to encourage someone else to risk it! 😁. No worries.

I might try it on my own here. Just learning to solder myself...maybe think about a soft-pack-build soon...if I prove halfway competent and don't get fried!🔥 Is it still the rule to never stick a metal fork into an electrical socket...I forget.⚡💪

Just didn't want to be the first rookie builder for this thread.😉
 

Neeko DeVinchi

E*POWAH Elite World Champion
Dec 31, 2020
1,033
1,376
UK
Oh man, now I gonna have to encourage someone else to risk it! 😁. No worries.

I might try it on my own here. Just learning to solder myself...maybe think about a soft-pack-build soon...if I prove halfway competent and don't get fried!🔥 Is it still the rule to never stick a metal fork into an electrical socket...I forget.⚡💪

Just didn't want to be the first rookie builder for this thread.😉
Don't sell yourself short.

Truth be told, I'd recommend not bothering to retrofitting a third party range extender. By the time you've put in the hard work, someone else (like Bafang) would probably release one which would simply plug into the system seamlessly.
Learning to solder is a good skill. Best recommendation is to start small.
E.g. I started by soldering connectors like xt60s to cables, in an effort to lengthen cables or make a bigger cable. Concentrate on getting a good technique, so you can solder safely👍🏿
 

mike_kelly

Well-known member
Subscriber
Aug 11, 2022
941
773
US
I don't think we will ever get a Bafang external battery for the CEF50. The cable going to the external connector is only designed to handle the current of Bafang's low power 2amp charger. SO I am afraid that the only route for this generation of CEF50 is to get out the soldering iron.

>> After thought: Bafang could supply and new cable and connector to install with a new external range extender.
 
Last edited:

TCFlowClyde

Active member
Feb 26, 2022
1,347
870
Mesa, AZ
Don't sell yourself short.

Truth be told, I'd recommend not bothering to retrofitting a third party range extender. By the time you've put in the hard work, someone else (like Bafang) would probably release one which would simply plug into the system seamlessly.
Learning to solder is a good skill. Best recommendation is to start small.
E.g. I started by soldering connectors like xt60s to cables, in an effort to lengthen cables or make a bigger cable. Concentrate on getting a good technique, so you can solder safely👍🏿
So, don't touch the active soldering iron to my tongue to make sure it's ready?😋
 

TCFlowClyde

Active member
Feb 26, 2022
1,347
870
Mesa, AZ
I don't think we will ever get a Bafang external battery for the CEF50. The cable going to the external connector is only designed to handle the current of Bafang's low power 2amp charger. SO I am afraid that the only route for this generation of CEF50 is to get out the soldering iron.
💯 Sadly I agree. Bafang is slooowwwww on innovation... they're more copy-cat traditionally. That's why I was surprised the M820-75Nm was so nice. Guessing Forestal engineering had some massive input.

But now that I've publicly committed to the battery extender, I'm gonna white-knuckle the process, and take a risk. 😎 Plus, I just bought my first Amazon soldering kit two months ago...can't waste a $30 purchase after all. Maybe Bafang will save me if I procrastinate enough. 👊
 

TCFlowClyde

Active member
Feb 26, 2022
1,347
870
Mesa, AZ
I know that’s been discussed. And I’ve never done something like that. Is there a cookbook i could follow the build one. With the right BMS for it?
Sounds like a build-off challenge? I risked the rear shock over-stroke... your turn?🫡 Plus, you're likely more successful of a risk taker than me jumping those big gaps and whatnot? 😱
 

Bengy22

Member
Aug 25, 2022
125
80
USA
Hey guys when riding with my super fit buddy on his FF Levo I’m developing a case of range anxiety with my 720wh. Are there any options you can think of for increasing range up to 900wh+?
I'm not sure if you can source a empty battery case but if you can and are open to diy you could place 6ah 21700's instead of the 5ah found in it. Would get you to 864wh so right under where you want to be but still 20% more capacity. I'm not sure if you go softpack if you could fit another parallel group, if you could though that might introduce its own issues though
 

Myalteregohamish

Active member
Jan 4, 2023
294
240
Vancouver, WA
Sounds like a build-off challenge? I risked the rear shock over-stroke... your turn?🫡 Plus, you're likely more successful of a risk taker than me jumping those big gaps and whatnot? 😱
I’ve been thinking about it. I’ve soldered a lot of my guitar pickups and pots so I’m “ok” with soldering iron. But I’m not confident in the process but I still have to read mikes link he posted.
 

patdam

Well-known member
Jan 17, 2019
902
601
france
skid plate quickly builded, those delivered with the bike has broken as soon as i touched it. Somebody have received the new rev more solid from SZZS ?
DSCF2048.JPG
 

TCFlowClyde

Active member
Feb 26, 2022
1,347
870
Mesa, AZ
View attachment 130595
They're testing it somehow apparently...
Looks like they're ready at $15 USD plus shipping according to Linda.💸

ZSSZ is not doing warranty or FOC (free of charge) until after one year apparently due to the high cost of the mold as they're trying to recovery some loss for Gen 1 & Gen 2 failures. 😝

Linda said they were NOT able to stress test it! Their torsion machine wasn't working?🤯😱😒

THIRD time is a charm, or three strikes you're out!💥
 

TCFlowClyde

Active member
Feb 26, 2022
1,347
870
Mesa, AZ
Here it is! My carbon sheathed-plastic motor-guard-monstrosity!
PXL_20231216_220722302.MP.jpg


It's definitely sturdy but also heavier than the plastic original with armor stripping.
PXL_20231216_215552816.PORTRAIT.jpg

PXL_20231216_215511304.PORTRAIT.ORIGINAL.jpg

The process is definitely messy and plenty of hand sanding to shape the broken side farings. This one needed repairing and splicing of plastic from Gen 1 motor guard. Basically, rebuilt from two pieces. Then, the other I broke during the repair process testing flex....easy fix to reinforce.

PXL_20231107_001456958.MP~2.jpg

PXL_20231215_203530107~2.jpg

It's got three layers of carbon fiber and lots of epoxy.
PXL_20231211_210151736.jpg
PXL_20231211_210202251.jpg

PXL_20231212_040454320.jpg

PXL_20231212_040442231.jpg

And lots of sanding....
PXL_20231215_203536416.jpg
PXL_20231215_203545452.jpg

And finally 2 layers of black glossy paint...
PXL_20231216_214940993.jpg


PXL_20231216_215016152.jpg

It's ugly and heavy but it should be protective as originally intended.
I would've been simpler and faster to have a complete plastic guard and just reinforce it fully with a carbon fiber outer shell.😝

Biggest challenge and setbacks: Re-building the curved side-fairing was a pain to glue with quick-set epoxy and probably tripled the project time.👊

Recommendations: have a backup plan if the new ZSSZ Gen 3 motor guard doesn't work. The carbon patch kit $50+ USD on Amazon and it won't take long to cover the plastic guard...if unbroken!😉
 
Last edited:

Phatty

Member
Feb 18, 2021
38
76
Utah
Got the bike wrapped recently… should have done it before I ride it but I was too excited. Anxious to replace the rear triangle with UDH…
Rode with pole violma and its Bosch motor today and 750wh battery. He smoked me everywhere uphill in emtb/auto and I was running sport and sport +
He ended with 40% and I ended with 63%. The shocking thing was just how good this bike handled downhill. I honestly thought the pole with its 190mm suspension would be way better but this little cef50 just rides so well. I beat him downhill several times and he is a better rider than me. Anyhow good to be back on the bike after having it gone getting wrapped for 2 weeks. I miss the power of the m600 ludi but this cef50 is light years ahead in handling and ride quality. Ran into bighorn sheep which was amazing.

IMG_3870.jpeg IMG_3872.jpeg IMG_3878.jpeg IMG_3874.jpeg IMG_3784.jpeg
 

TCFlowClyde

Active member
Feb 26, 2022
1,347
870
Mesa, AZ
Got the bike wrapped recently… should have done it before I ride it but I was too excited. Anxious to replace the rear triangle with UDH…
Rode with pole violma and its Bosch motor today and 750wh battery. He smoked me everywhere uphill in emtb/auto and I was running sport and sport +
He ended with 40% and I ended with 63%. The shocking thing was just how good this bike handled downhill. I honestly thought the pole with its 190mm suspension would be way better but this little cef50 just rides so well. I beat him downhill several times and he is a better rider than me. Anyhow good to be back on the bike after having it gone getting wrapped for 2 weeks. I miss the power of the m600 ludi but this cef50 is light years ahead in handling and ride quality. Ran into bighorn sheep which was amazing.

View attachment 130857 View attachment 130858 View attachment 130859 View attachment 130860 View attachment 130861
Awesome! Cool to see the Big horn!

Did one take a charge at you and glance that stay when descending ?😱😁
 

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