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

[temon10]

Linda just told me that there is 48v version of M820. So she also offer 48v battery now.

 

[TCFlowClyde]

Zhaosheng tech's motor cover mod. I wonder what the material was originally made for? No vents?

View attachment 118903

Can you poke some holes to vent better?

 

[temon10]

Zhaosheng tech's motor cover mod. I wonder what the material was originally made for? No vents?

View attachment 118903

the original is like mine made of plastic which has broken due to being hit by a rock. they just added a rubber shield to gain strength. make it some hole so water does not stay.

 

[TCFlowClyde]

Thanks TC for always being so informative as usual. I would have never guessed those names. I am a bit confused though on your wording.

so it seems I have the following:

-most anterior set of mounting screws: steel deft bolt, the black thicker washers, and one screw that was holding it.
-from the middle motor attachment: I only have the longer black female thru-bolt-like shaft bolt. Do not have the opposite side screw / washer.
-For the rear motor attachment: I've lost both the longer black female thru-bolt-like shaft bolt and the opposite screw / washer.

View attachment 118915

Seems all I need are a couple fhss/washers and a rear bolt.
Anyone know what the length of the longer black female bolt would be for the rear motor attachment?

Thanks TC for always being so informative as usual. I would have never guessed those names. I am a bit confused though on your wording.

so it seems I have the following:

-most anterior set of mounting screws: steel deft bolt, the black thicker washers, and one screw that was holding it.
-from the middle motor attachment: I only have the longer black female thru-bolt-like shaft bolt. Do not have the opposite side screw / washer.
-For the rear motor attachment: I've lost both the longer black female thru-bolt-like shaft bolt and the opposite screw / washer.

View attachment 118915

Seems all I need are a couple fhss/washers and a rear bolt.
Anyone know what the length of the longer black female bolt would be for the rear motor attachment?

Yipes! I would contact Linda ASAP to get a full replacement motor mount hardware setup. I'd say off-hand you're missing 40% unfortunately. Several OEM black thick spacers/beveled washers, the remaining black alloy female thru-bolt and 5 black hex bolts.

I recommend telling her to warranty all of it if possible.

It took 3-days of confusing dialogue with pictures for Linda to confirm the main pivot screw dimensions I was missing. It'll be faster and easier to request the complete hardware set.

Maybe have her to send air express. And pay extra? Anything under a $100 might be worth not losing weeks instead of days.

I might also try the Bafang heavier 3 steel mounting bolts with corresponding nuts that should've been included. The widths should be same. That may assist with the missing black alloy thru-bolt somehow?

 

[thaeber]

Linda just told me that there is 48v version of M820. So she also offer 48v battery now.

Thanks for the info! Would be interesting to know if there is any advantage on higher capacity available, eg. 13S4P 21700 960Wh battery. Otherwise, at 13S3P, it‘s still 720 Wh and I don’t see any advantage, but loosing the 36V bottle battery range extender option.

 

[spokémon]

Thanks for the info! Would be interesting to know if there is any advantage on higher capacity available, eg. 13S4P 21700 960Wh battery. Otherwise, at 13S3P, it‘s still 720 Wh and I don’t see any advantage, but loosing the 36V bottle battery range extender option.

Do you know if 13s4p will fit?

 

[spokémon]

I tried to search but couldn't find a clear answer.
Has anybody found an after market spider or direct mount chainring to fit?
Is the interface specific to Bafang M820 motors? or is it compatible to say Bosche Gen 4 or Yamaha?

 

[brbr]

I tried to search but couldn't find a clear answer.
Has anybody found an after market spider or direct mount chainring to fit?
Is the interface specific to Bafang M820 motors? or is it compatible to say Bosche Gen 4 or Yamaha?

this one is for a Bosch : https://www.bike24.fr/produits/417588
Someone said it would not fit because the offset is different, but I don't have the offset figures
EDIT: Bosch Offset is 52mm

 

[spokémon]

this one is for a Bosch : https://www.bike24.fr/produits/417588
Someone said it would not fit because the offset is different, but I don't have the offset figures
EDIT: Bosch Offset is 52mm

what offset do we need?
so the Bosch interface is ok and will fit?

 

[LAnton]

Thanks for the info! Would be interesting to know if there is any advantage on higher capacity available, eg. 13S4P 21700 960Wh battery. Otherwise, at 13S3P, it‘s still 720 Wh and I don’t see any advantage, but loosing the 36V bottle battery range extender option.

13S4P 21700 - 720W The weight of the battery without the case is 3 kg. 13S3P 21700 - 540W Weight 2,2 кг.Or am I wrong?

 

[thaeber]

Do you know if 13s4p will fit?

Thats the question - 52 cells 21700. may be @LAnton can judge on it, he did a huge softpack battery. Otherwise just wait for an update from Linda…

 

[LAnton]

Thats the question - 52 cells 21700. may be @LAnton can judge on it, he did a huge softpack battery. Otherwise just wait for an update from Linda…

Oh sorry, I didn't see the 43V right away

 

[thaeber]

13S4P 21700 - 720W The weight of the battery without the case is 3 kg. 13S3P 21700 - 540W Weight 2,2 кг.Or am I wrong?

13S4P = 48V x 20Ah = 960Wh. appr. 70g per cell x 52 = 3,65 kg plus holders, welding material, BMS..

 

[thaeber]

Oh sorry, I didn't see the 43V right away

…48V, 13S = 13x3,6 V..

 

[LAnton]

13S4P = 48V x 20Ah = 960Wh. appr. 70g per cell x 52 = 3,65 kg plus holders, welding material, BMS..

45 см. Length

 

[LAnton]

…48V, 13S = 13x3,6 V..

Have you already ordered a 48V motor?

 

[Herculesridesebikes]

what fork offset is reccomended for this frame is it 51mm? is anyone running a 170 fork with a 210x52.5 shock in a mullet setup?

 

[thaeber]

Have you already ordered a 48V motor?

No, just saw the update above and started to think about…

 

[thaeber]

45 см. Length

View attachment 118940

Hmmm.. this means 6 x 21700 cells in a row is max., summing up to 420 mm. Using the original housing means 42 cells (6 in a row at 70 mm each, 7 per row according to the cell holders, = 42 cells). Not good for a 48v configuration. The 36V option 720Wh seams to be a very good choice..

 

[spokémon]

what fork offset is reccomended for this frame is it 51mm? is anyone running a 170 fork with a 210x52.5 shock in a mullet setup?

TC was running mullet 210x55 shock 180mm fork

M820 Bafang - CEF50 frame (lightweight)

Oh, it’s motor output not peddling power like a cycling power meter,well that’s useless. I want to know my performance not the electric motors. Exactly. Motor Output Power in Watt. But the Calorie counter measures Your power input via the torque sensor, at least You can derive Your average...

www.emtbforums.com

 

[stuff]

what fork offset is reccomended for this frame is it 51mm? is anyone running a 170 fork with a 210x52.5 shock in a mullet setup?

42mm offset works perectly fine.

Also 210x52.5 is even possible in 29

 

[LAnton]

Oh sorry, I didn't see the 43V right away

42mm offset works perectly fine.

Also 210x52.5 is even possible in 29

I didn't see any difference between 51 and 42.

 

[LAnton]

Hmmm.. this means 6 x 21700 cells in a row is max., summing up to 420 mm. Using the original housing means 42 cells (6 in a row at 70 mm each, 7 per row according to the cell holders, = 42 cells). Not good for a 48v configuration. The 36V option 720Wh seams to be a very good choice..

More 21700 cells can be inserted into the frame. But it will be difficult to fix them in the frame. I'm also thinking of buying a 720W battery. But I will remove the case and leave the aluminum rod so that the battery can be firmly fixed in the frame.

 

[stuff]

I didn't see any difference between 51 and 42.

You have to be quite sharp to notice it tbh. Fairly noticeable for any average rider

 

[Bengy22]

Linda just told me that there is 48v version of M820. So she also offer 48v battery now.

Did Linda indicate the max amperage for this version, curious if they are limiting the amps on the 43v and 48v to peak around the same wattage as the 36v or if all have the same amps leading to higher watts for more volts.

 

[thaeber]

Did Linda indicate the max amperage for this version, curious if they are limiting the amps on the 43v and 48v to peak around the same wattage as the 36v or if all have the same amps leading to higher watts for more volts.

Thats exactly what they do with M500/510. 48V = 14A limit. 43V = 16A limit. 36V = 18A limit.

 

[mike_kelly]

what offset do we need?
so the Bosch interface is ok and will fit?

Bosch spline is not compatible.

 

[temon10]

Bosch spline is not compatible.

@LAnton said it is the same with M510 spider chainring.

 

[Bengy22]

Thats exactly what they do with M500/510. 48V = 14A limit. 43V = 16A limit. 36V = 18A limit.

That's where the idea of mine came from, just different software loaded but nothing different hardware side. But given that Idea though wouldn't the torque figures be off though? Because if they are compensating for the higher voltage by lowering amps that would lower the torque at the crank but it would have higher rpm (but on a pas only motor I don't see higher rpms very helpful). I guess you could compensate by running a smaller cog in the front but to me I don't see a reason to not go 36v unless like other bafang motors you can find a way to run the full amps on a higher voltage battery

 

[spokémon]

@LAnton said it is the same with M510 spider chainring.

@LAnton could you please confirm. M510 spider will work on M820?