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

[TCFlowClyde]

My experience is that the M820 is very smooth. If you read back in the thread someone commented that the start angle could be adjusted so that there is no delay. I have not really noticed it as a problem. I notice no delay in the change of assist levels. I did not want an electric motorcycle. I first started with a bike with a BBSHD and it only had a cadence sensor. So it could jerk around. If you just rotated the pedals a bit in the boost mode you would take off. I loved the Orbea because it was more like "a tailwind" and so is the M820 to me. But I am a user who does not want a full eMTB experience so take my comments with a "grain of salt". I want to feel like I am riding a MTB, just with a little help. Others may be Enduro riders that want a big boost back up to the top. Maybe someone who owns a full power Bafang like TC will comment about the comparison.

I'm enduro-trail..."trail duro"? But I've ridden both the RS60 and EP8 (more extensively). Shimano is smoother, but not by much, but quieter on ramp up than the M820. You get used to the soft whir. I have factory settings still on the M820...they work for me. So, tuning it really has not appealed to me. I tend to ride "3-5" sport to boost power levels. 3 in flats 4 on slopes and 5 on tech steeps.

Inherently, all the 85 Nm+ full power systems can be a little rough on shifting. Nature of the higher torque, so Boost at 75 Nm requires some skill and pedal cadence control to not snap a chain. I also run 32T chainring to help control overrun which isn't bad.

Only thing I'd change for the M820 would be a lower battery reservation/power down to at a more optimal 12-15% rather than 20% Bafang firmware hack anyone?

But the bigger 720 Wh battery mitigates that somewhat. And hopefully, the DIY battery extender will be a step-by-step guide for us non-engineering types to follow in the near future.

 

[TCFlowClyde]

You're right to say that. I drove the M820 for several months and it was boring for me. I missed the M600 engine. Now I'm riding the M560. It's more fun for me to ride on the M560 and I'm having fun.

I have my M600 still. I don't miss the 10 lbs extra weight. But yeah, easier to ride with more advanced, full-powered riders...which is rare these days for me.

My M820 is not as limiting as I thought it would be...still fun and feels more agile and "analogue-like" in lower power modes.

Definitely nice to have the "forbidden" longer travel (180/165) too of my M820 build.

 

[92se-r]

My e8000 shimano was "full power" at 70nm. My buddy with a kenevo sl with 35nm couldnt keep up. So this m820 at 75nm should technically full power too? Bafang m600 seems ridiculous at 120nm. I too like that natural mtb feeling with occasional stints at boost mode for full power but on real mtb trails, i dont see how its possible to stay in that mode.

Thats why im asking how it compares to other full power motors that arent bafang. I was worried they lied about their torque rating.

 

[TCFlowClyde]

My e8000 shimano was "full power" at 70nm. My buddy with a kenevo sl with 35nm couldnt keep up. So this m820 at 75nm should technically full power too? Bafang m600 seems ridiculous at 120nm. I too like that natural mtb feeling with occasional stints at boost mode for full power but on real mtb trails, i dont see how its possible to stay in that mode.

Thats why im asking how it compares to other full power motors that arent bafang. I was worried they lied about their torque rating.

I'd estimate 85-90% the EP8-85Nm.

Others with the EP8 current might chime in.

The M600 is fun and climbs really well with that torque. Just drop the saddle and pedal up almost any singletrack. The M820 is 80% of my M600 boost top end.

Again others can offer a direct comparison with their full powered.

I'd categorize the M820-75Nm as 3/4 powered . So steeper climbs in boost need some finesse, but that's what I like about it. I like to climb tech with some feel like my old analog... just not struggle quite as much especially if I'm already winded.

 

[Freda]

I have been debating between the cef50 and the lightcarbon version. I think the biggest selling point for me is the larger cavity and ability to diy a larger battery for the same weight as the 410wh battery. Does anyone have the internal cavity dimensions for the cef50

I don’t know the available space for the cef50, but you can make a diy 800Wh in the lce930 so that should be enough.

Additionally, ive noticed both frames have rather long chainstays, with the lightcarbon being worse. I am used to 435 to 440mm chainstays. Have you guys noticed ill handling effects going to a 450mm chainstay? Have you guys confirmed it actually is 450?

The long chainstay makes lifting the front wheel harder, also since battery is making the front heavier. It is something you get used to. I came from analogue bike so difference was huge, but any e-bike is more or less same. The benefits are a much more stable bike at speed and while climbing. You are more centered on the bike, especially while standing, so you get naturally more weight on front wheel and more grip. It prevents the front wheel lifting when climbing.

 

[calvintys]

I don’t know the available space for the cef50, but you can make a diy 800Wh in the lce930 so that should be enough.



The long chainstay makes lifting the front wheel harder, also since battery is making the front heavier. It is something you get used to. I came from analogue bike so difference was huge, but any e-bike is more or less same. The benefits are a much more stable bike at speed and while climbing. You are more centered on the bike, especially while standing, so you get naturally more weight on front wheel and more grip. It prevents the front wheel lifting when climbing.

I read some where before, Shimano or Bafang motor, ON 29ER the shortest chainstay u get its 450mm and 275 (mullet) 440mm. No matter what brand frame u get will not be any shorter, unless u go for Bosch or Brose.

My frame finally ship today. Cant wait to compare the ride with my Giga 290 (chainstay 445).

 

[Neeko DeVinchi]

.....I was worried they lied about their torque rating.

They haven't.
It does feel like legit 75NM of torque in the highest level of assist.

I remember testing the peak output of the M820 and recording the watts via the app.
On average I achieved 530-ish peak watts. But I did see it spike upto 571watts.

Even if friends of mine ride ebikes like Levos etc, I don't feel that the CEF50 with the M820 I'd being outperformed in terms of power and support. In terms of range, naturally a 410wh battery won't last as long as a 700wh+.

Personally, the M820 is becoming one of my favourite Bafang motors. (Maybe No.2). No.1 spot remains M620. But that could change in a month's time

 

[92se-r]

Seems like they are only offering 36v or 48v now and not offering ft014 43v battery anymore.

Was there a price difference between the 480wh vs the 720wh battery? They only gave me a quote for the 720wh.

How did you guys handle payment?

 

[mike_kelly]

Frankly I think it is different for different people. Originally I had to pay CC via Alibaba, they would not accept paypal. I believe others have been able to use paypal?

 

[Neeko DeVinchi]

@92se-r , the guys over at Changzou Feildebikes provided me with the entire M820 system.

Bafang Newest Motor Bafang M820 36v 43v 250w Mm G532.250.c Electric Bike Kit Cst - Buy 36v 250w Electric Bike Kit Cst Bafang M820 Motor,250w Central Motor Kit Bafang M820 Kits,E Bike Conversion Kit E Bike Conversion Kit Mm G532 M820 Motor Product on

Bafang Newest Motor Bafang M820 36v 43v 250w Mm G532.250.c Electric Bike Kit Cst - Buy 36v 250w Electric Bike Kit Cst Bafang M820 Motor,250w Central Motor Kit Bafang M820 Kits,E Bike Conversion Kit E Bike Conversion Kit Mm G532 M820 Motor Product on Alibaba.com

x.alibaba.com

I was provided the frame separately from a distributor for the CEF50 & CEF52.

From experience, I tend to find that you can reduce the cost for building up a frameset ebike if you source components separately.

Rumour has it that GBK will soon start selling the CEF50 frames as well

 

[TCFlowClyde]

Rumour has it that GBK will soon start selling the CEF50 frames as well

That actually could be a good thing. GBK could have the manufacturer (SZZS) develop things and test them out easier than the direct consumer model for for those of us that already have the CEF50 frame and just want upgrades that work and make sense for E-mtbing.

Hopefully they wouldn't make it just proprietary and exclusive.

 

[calvintys]

Seems like they are only offering 36v or 48v now and not offering ft014 43v battery anymore.

Was there a price difference between the 480wh vs the 720wh battery? They only gave me a quote for the 720wh.

How did you guys handle payment?

Call me silly or risk taker, i use wise..com to bank in directly to linda personal bank account to save some exchange rate n interest. Anyway my battery will have carbon case and upgraded my frame from T700 carbon to T800 to safe 230 gram n stiffer geometry.

I wanted to get carbon crank too but it fail their internal test so i need wait for few weeks more.

Let hope end of next week once my frame arrives, i will post their carbon battery case weights.

 

[92se-r]

Call me silly or risk taker, i use wise..com to bank in directly to linda personal bank account to save some exchange rate n interest. Anyway my battery will have carbon case and upgraded my frame from T700 carbon to T800 to safe 230 gram n stiffer geometry.

She didnt mention any upgrade options to me. Their specs list 2400g for the frame, is it 2170g with t800?

 

[calvintys]

She didnt mention any upgrade options to me. Their specs list 2400g for the frame, is it 2170g with t800?

Who did you contact? Did u contact linda? I am their first customer to get those options... Your information 2400gram its in raw mate mate so if u paint it add another 200 gram plus.

Please WhatsApp linda +8619313711220 to get more information. China block WhatsApp so she need to use VPN to enable sometime her VPN its off so u can call or sms her to ON her VPN.

 

[tepe]

Call me silly or risk taker, i use wise..com to bank in directly to linda personal bank account to save some exchange rate n interest. Anyway my battery will have carbon case and upgraded my frame from T700 carbon to T800 to safe 230 gram n stiffer geometry.

I wanted to get carbon crank too but it fail their internal test so i need wait for few weeks more.

Let hope end of next week once my frame arrives, i will post their carbon battery case weights.

What battery did you choose with carbon case? 400wh or 700wh?

 

[calvintys]

What battery did you choose with carbon case? 400wh or 700wh?

48v 480wh

 

[tepe]

48v 480wh

I asked Linda about 700wh 48V carbon version: right now they don't plan to produce such version.

 

[calvintys]

I asked Linda about 700wh 48V carbon version: right now they don't plan to produce such version.

I think its because m820 fall under SL category, alot of big brand SL bike below 400wh, sp kenevo Sl is 320wh.

 

[patdam]

I asked Linda about 700wh 48V carbon version: right now they don't plan to produce such version.

I have purchased the 700W, based on my experience with M510. It's a mistake, i will be physically empty before i reach 50% of the battery. 500 w with 1Kg less will be better choice for my point of view

 

[Myalteregohamish]

I own an EP8 and I also have ridden the CEF50 with the M820 motor. There is a massive difference between the two. The lower cadence raw power required to do steep pitches is much more helpful on the EP8 than it is on the M820. I get dropped regularly on steep pitches by my normal riding buddy on his levo. We both ride in Eco or trail and on the M820 I have to use significantly more boost to keep him in view. The trade-off with the M820 is if I want that kind of power and raw torque at lower cadence, such as with steep, climbs and pitches then I have to use higher boost modes which drains the battery significantly quicker. I am working on a way to produce a range extender which would take my 720 W hour up to close to 1000. At that point though the question of weight and the m510 proposition is apparent. From reading the 510 motor forum it looks like they get much more efficiency out of an 840 W battery at 48 V with a 510 motor , than we do trying to achieve the same type of power with the M820. So these are the real world scenarios and trade-offs that I have found in my experience. Keep in mind I live in the Pacific Northwest and mountains are steeper here all around. When the grades aren’t quite as steep (Sacramento foothills) , then you get better battery range because it requires less boost with M820.

I’ll also add that there’s a significant drop off at 25% I believe, but if I had 10% more before the drop off happened that would be a huge help I don’t know if anybody’s figured that out yet.

 

[patdam]

I own an EP8 and I also have ridden the CEF50 with the M820 motor. There is a massive difference between the two. The lower cadence raw power required to do steep pitches is much more helpful on the EP8 than it is on the M820. I get dropped regularly on steep pitches by my normal riding buddy on his levo. We both ride in Eco or trail and on the M820 I have to use significantly more boost to keep him in view. The trade-off with the M820 is if I want that kind of power and raw torque at lower cadence, such as with steep, climbs and pitches then I have to use higher boost modes which drains the battery significantly quicker. I am working on a way to produce a range extender which would take my 720 W hour up to close to 1000. At that point though the question of weight and the m510 proposition is apparent. From reading the 510 motor forum it looks like they get much more efficiency out of an 840 W battery at 48 V with a 510 motor , than we do trying to achieve the same type of power with the M820. So these are the real world scenarios and trade-offs that I have found in my experience. Keep in mind I live in the Pacific Northwest and mountains are steeper here all around. When the grades aren’t quite as steep (Sacramento foothills) , then you get better battery range because it requires less boost with M820.

I’ll also add that there’s a significant drop off at 25% I believe, but if I had 10% more before the drop off happened that would be a huge help I don’t know if anybody’s figured that out yet.

With 720w you have not enough , i don't understand ? with mine 48V i consume +- 25% to climb +-1000 M , on a bucle +- 25km. I ride in the pyrenéée, the climbs are between 10 ans 20%. (if more, i use the walk). It's +- half less than the M510 on the same track. I use 3 modes and i'm mostly in 2 and 3. May be my HMI displaying wrong value? but i have allready done 2 time the bucle without charging and i had consumed +- 50%.

 

[Myalteregohamish]

Yes, that’s correct, the drain is consistent with ep8 where I would have consumed around 70% over 5000 feet of climbing around 10 to 25% grade. On my M820 I would not be able to do anywhere near that. I am running in trail plus using about 48 of torque. I weigh 185 pounds and I’m contributing anywhere between 200 and 500 W of my own energy depending on the effort and steepness of the climb. My overall estimated contribution of my own power on an average ride is 180-190 watts over around 2:15 mins of moving time.

The top one is the M820 the bottom one is EP8. The top one I’m always concerned about range the bottom one I never think about it. There’s something about running a higher cadence that allows me to output, more energy, more consistently, and the numbers show that. That all comes from the EP eight ability to have more support From a torque perspective/peak output, power perspective.


Does the voltage (48 versus 36) have an effect on how much output power there is available?

I added this last one as a comparison on my kenevo SL with the 1.1 motor. You can see I’m putting in less of my own effort the lower the power output of the motor. I should also disclose that this is with two range extenders totaling 720 W a total capacity. I am left with about 30% after everything’s all said and done. I’m not sure if that’s the same for everybody but if something about a higher output motor that causes me to feel like I want to put more into it.

 

[Neeko DeVinchi]

My experience with the M820 and the CEF50 has been different.

I do appreciate that the CEF50 is a versatile trail emtb. But I'm finding that the bike gets used more for power hour sessions or group rides instead of Allmountain excursions which would favour an ebike with a bigger battery.

I have no doubt that if someone raced emtbs with similar geometry & components uphill and were all using different full powered motor systems from Bosch, Shimano, Brose, Yamaha, Polini etc, the M820 'might' fall short in terms of battery capacity. But in those circumstance, typically the M510 would be the appropriate motor system to compare.

Moreso I enjoy the power-to-weight performance of the CEF50 and M820 system in terms of providing support consistently, especially if the rider isn't a featherweight cross-country racer.

Whilst (in my opinion) I still classify the CEF50 as a full fat/full powered emtb, it isn't lost on me how many riders who I've borrowed the bike too (who wouldn't classify themselves as featherweight either), who have all explained that this is the natural progression and innovation riders wanted 3years ago. Not the 'Superlight' category which barely provides any assistance, support or favourable range unless the rider is lightweight ans are incapable of keeping up with full-fat/full-powered ebikes. Rather, an ebike which weighs less, performs like a full-fat/full-powered ebike, implemented to a frame with up to date geometry and 4 frame sizes to choose and doesn't cost no where near a mainstream emtb of a similar weight.

For me and a lot of my friends who i build for, this bike represents a true turning point for getting more bums on saddles who don't have disposable incomes. But don't want a 25kg+ emtb to which could pull your back out by lifting it over an fence gate etc. Riders who want something (dare I say), mainstream which doesn't penalise you for being heavy, whilst capable of offering a good amount of power/support/control when being used.

600miles and no issues to speak of (unless you count a snapped chain and using insolation foam to silence the cable rattle within the downtube).
As much as some riders and members may have a hard time believing it. But

This is the true ebike of the year 2023. The true people's champion for electic mountain bikes.

No regrets everyone. Thanks again all of you for recommending this fantastic frameset

 

[mike_kelly]

Does the voltage (48 versus 36) have an effect on how much output power there is available?

No, if you have two 500whr batteries they have the same power output at 48v or 36v.

 

[Myalteregohamish]

No, if you have two 500whr batteries they have the same power output at 48v or 36v.

Ok thank you for clarifying. I was reading the m510 thread (all64 pages) and the voltage comparisons gave me the impression that higher voltage was getting better peak output.

 

[Myalteregohamish]

My experience with the M820 and the CEF50 has been different.

I do appreciate that the CEF50 is a versatile trail emtb. But I'm finding that the bike gets used more for power hour sessions or group rides instead of Allmountain excursions which would favour an ebike with a bigger battery.

I have no doubt that if someone raced emtbs with similar geometry & components uphill and were all using different full powered motor systems from Bosch, Shimano, Brose, Yamaha, Polini etc, the M820 'might' fall short in terms of battery capacity. But in those circumstance, typically the M510 would be the appropriate motor system to compare.

Moreso I enjoy the power-to-weight performance of the CEF50 and M820 system in terms of providing support consistently, especially if the rider isn't a featherweight cross-country racer.
View attachment 131450
Whilst (in my opinion) I still classify the CEF50 as a full fat/full powered emtb, it isn't lost on me how many riders who I've borrowed the bike too (who wouldn't classify themselves as featherweight either), who have all explained that this is the natural progression and innovation riders wanted 3years ago. Not the 'Superlight' category which barely provides any assistance, support or favourable range unless the rider is lightweight ans are incapable of keeping up with full-fat/full-powered ebikes. Rather, an ebike which weighs less, performs like a full-fat/full-powered ebike, implemented to a frame with up to date geometry and 4 frame sizes to choose and doesn't cost no where near a mainstream emtb of a similar weight.

For me and a lot of my friends who i build for, this bike represents a true turning point for getting more bums on saddles who don't have disposable incomes. But don't want a 25kg+ emtb to which could pull your back out by lifting it over an fence gate etc. Riders who want something (dare I say), mainstream which doesn't penalise you for being heavy, whilst capable of offering a good amount of power/support/control when being used.
View attachment 131451
600miles and no issues to speak of (unless you count a snapped chain and using insolation foam to silence the cable rattle within the downtube).
As much as some riders and members may have a hard time believing it. But
View attachment 131452
This is the true ebike of the year 2023. The true people's champion for electic mountain bikes.

No regrets everyone. Thanks again all of you for recommending this fantastic frameset

I have to agree with you. I think the CEF50 has been an excellent bike and punches well above its weight. The riding I do with 170 mm fork and a 150 mm shock is impressive to say the least. If I could have that frame with either an EP8 or a m510 I’d be set.

 

[Dado]

Ok thank you for clarifying. I was reading the m510 thread (all64 pages) and the voltage comparisons gave me the impression that higher voltage was getting better peak output.

Hello.

Each firmware has some allowed current. With M510 48V it is 14A. FC1.0 did overshoot even 2A. Latest FC2.0 has really good regulation. So with full battery and good voltage sag it is over 700W. Just wanna say, it is not a rule there is higher peak with hgher voltage. Bafang set max current to keep cca 700W at all voltages.

And for your problem with power limitation. Check K1 BB Racing.

 

[mike_kelly]

of course all bets are off if the manufacturer does something like the EP8RS in hardware or firmware.

 

[Myalteregohamish]

Hello.

Each firmware has some allowed current. With M510 48V it is 14A. FC1.0 did overshoot even 2A. Latest FC2.0 has really good regulation. So with full battery and good voltage sag it is over 700W. Just wanna say, it is not a rule there is higher peak with hgher voltage. Bafang set max current to keep cca 700W at all voltages.

And for your problem with power limitation. Check K1 BB Racing.

View attachment 131453

Ok since this is new to me, are you saying get a BBRacing device and use it to set the taper of wattage from 25% down to to 10%? Which would give me another 15% of available battery at max output?

 

[mike_kelly]

You can do that but remember you will reduce your recharge lifecycle. You pays your money and makes your choices.