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

[TCFlowClyde]

Did you guys get the side cover or only the bottom cover for the M820?
View attachment 118799

Fortunately, not needed! Looks like the frame/motor mount area are integrated. One less thing to lose/break.

 

[mike_kelly]

 

[TCFlowClyde]

View attachment 118800

Yep... definitely Bafang charge port. I have one for my M600 Bafang batteries. But the point is, most will want the threaded cap, 4-prong if it doesn't cost too much to upgrade.

 

[mike_kelly]

The cost of the socket and plug is only $5 but you need to be able to "ring out" the Bafang cable and cut it off soldering the wires to the new plug.

https://www.aliexpress.us/item/2251832222453608.html?spm=a2g0o.productlist.main.1.5ef53bdfEJzfRo&algo_pvid=9406e454-1afe-4087-98e2-d177e5edd4b4&algo_exp_id=9406e454-1afe-4087-98e2-d177e5edd4b4-0&pdp_npi=3%40dis%21USD%214.5%214.5%21%21%21%21%21%40211bd7bf16877204135272511d0c55%2154343002135%21sea%21US%211615972092&curPageLogUid=oOqbWVzAvTsj

Even tho the socket is the same shape it is not exactly a perfect replacement fit. I would have to be shaved down for a perfect fit. But it fits over the top and the screws work after just reaming out the holes in the new socket a tiny bit. Then I will put just a touch of sealant under it.

 

[TCFlowClyde]

I need to learn some soldrering skills. Good time to start in simple things for practice.

 

[Waynemarlow]

Actfually they probably do have the most capacity. Watts is watts. But as Thaeber pointed out watts=voltage*current. So more voltage gives more watts for the same current. But since each cell is the same voltage 3.7v you need more cells to make a 43v battery than a 36v battery.

Some would argue that high torque is aided by higher current capability and high speed is aided by higher voltage. You don't get both and light weight and small space.
In this thread are the weights of the different batteries.

Mike, please can you link any articles which you have researched to come up with these conclusions, it would be useful for us to understand your deductions.

Sorry but high torque is not always beneficially aided by more amps, more how the motors total stator size and field windings are organised, together with the computer control of how volts and amps are sent to each part of the motor. Equally high voltages will not always gain extra speed, sometimes a higher rev ( equating to cadence at the pedals ) limit but that is now being negated with the computer control now being used in EBike motors.

Motors, batteries and the design of modern combinations of the said motor and battery is complicated and becoming more complicated by the day, however the basic principles of how we convert energy into rotation for our transport purposes is as old as the 1894 Electrobat.

 

[mike_kelly]

I did not say I said that nor believe it. But high torque does require high current.

 

[mike_kelly]

I need to learn some soldrering skills. Good time to start in simple things for practice.

I really hate soldering large wires. With modern connectors it is easy to melt the connector trying to get a good solder joint. I use a metal frame to hold the connector with Xt60 but most other connectors don't have holders available.

 

[Myalteregohamish]

I really hate soldering large wires. With modern connectors it is easy to melt the connector trying to get a good solder joint. I use a metal frame to hold the connector with Xt60 but most other connectors don't have holders available.
View attachment 118805

Way above my pay grade. But if you’ve got the skills and understanding.

 

[TCFlowClyde]

One of the frame design issues that I brought up in the past was the lack of seatstay crossbar. It does have a beefy all-carbon rocker arm. So, it seemed unusual, thinking that it's a weight savings strategy. Yet is it at the expense of lateral support? I don't know if this true, and I don't feel it in the frame performance...yet!

However, after seeing some of the same lighter, full-powered designs (both carbon and alloy) from recent Eurobike internet video, is having no crossbar sound from an engineering perspective?

Any legit structural/mechanical engineers in this forum that might be able to explain at a SIMPLE level if this is indeed structurally superior to having a crossbar vs. not? Just curious as a layperson.

 

[TCFlowClyde]

Way above my pay grade. But if you’ve got the skills and understanding.

Trying to learn. More out of necessity than intense curiosity.

As long as it's an upgrade...should be worth it, water-resistant-wise. Our monsoon season is a foot, it's even more intense in our alpine mountains where I truck camp in the forest. So, it would be a worthy endeavor for me.

 

[LAnton]

Did you guys get the side cover or only the bottom cover for the M820?
View attachment 118799

I bought 2 motors without a frame. The 2x motor had a side and bottom cover. The bottom cover does not fit the CEF50. I bought one motor with a CEF50 frame, only the bottom cover is included.

 

[LAnton]

I did a temperature measurement of the battery 15ah yf CEF50. The battery was packed in insulation. I have completely drained the battery at maximum acceleration. The battery temperature was 25 degrees. celsius. The temperature outside was +10 degrees.

 

[temon10]

This is the headset from Tantan frame. Anyone know where I can buy this headset?

 

[langharr]

im confused whether to get a 36v or 43v motor

It seems like a 36V is more versatile and allows for a battery bottle to be run in parallel if extra battery is needed - correct?

Are the plugs posted in the lat 2 pages - are these intended for connecting a battery bottle?

Thanks

 

[thaeber]

One of the frame design issues that I brought up in the past was the lack of seatstay crossbar. It does have a beefy all-carbon rocker arm. So, it seemed unusual, thinking that it's a weight savings strategy. Yet is it at the expense of lateral support? I don't know if this true, and I don't feel it in the frame performance...yet!

However, after seeing some of the same lighter, full-powered designs (both carbon and alloy) from recent Eurobike internet video, is having no crossbar sound from an engineering perspective?

Any legit structural/mechanical engineers in this forum that might be able to explain at a SIMPLE level if this is indeed structurally superior to having a crossbar vs. not? Just curious as a layperson.
View attachment 118812

If You look at it from an engineering perspective, the two seatstays are working like independent pushrods if there is no crossbar. But they cant, because of the stiff rear axle, and the massive one pice rocker arm. I doubt that a crossbar would lead to any noticeable improvement here.

 

[TCFlowClyde]

If You look at it from an engineering perspective, the two seatstays are working like independent pushrods if there is no crossbar. But they cant, because of the stiff rear axle, and the massive one pice rocker arm. I doubt that a crossbar would lead to any noticeable improvement here.

So, just a little extra weight to shave off then...makes sense.

 

[Polak_B]

colleagues, tell me, when buying a frame from Linda, do we get any plugs in these places? what are these holes for?

 

[temon10]

colleagues, tell me, when buying a frame from Linda, do we get any plugs in these places? what are these holes for? View attachment 118841

this hole for 720Wh battery holder

 

[Polak_B]

ok, but what if we don't have such a battery? is there a hole then?

this hole for 720Wh battery holder

 

[temon10]

ok, but what if we don't have such a battery? is there a hole then?

ask Linda for sure. But I think U can make 3D printing to close that hole.

 

[mike_kelly]

im confused whether to get a 36v or 43v motor

It seems like a 36V is more versatile and allows for a battery bottle to be run in parallel if extra battery is needed - correct?

Are the plugs posted in the lat 2 pages - are these intended for connecting a battery bottle?

Thanks

The CEF50 is not designed to have an external battery. Bafang may eventually design an internal battery and cabling to accommodate an external battery but the availability is unknown. The last connector shown is a DIY attempt to add the needed connector for an external battery. The connector for charging only needs to support 2-4amps but for powering the motor externally that connector is required to support 7-10 amps or more at peak.

@langharr To answer your question. There are no premade 43v batteries out there. Lots of 48v and 36v. So you have more battery choices with 36v. But there is no stock way of adding an extra 36v battery without some DIY modificatiions. The 36v and 43v batteries made by Bafang are late in being produced and are not yet available. The majority of the current buyers bought 36v 720wh batteries that were made custom for Zhaosheng by a contractor because they are available now.

 

[brbr]

im confused whether to get a 36v or 43v motor

It seems like a 36V is more versatile and allows for a battery bottle to be run in parallel if extra battery is needed - correct?

Are the plugs posted in the lat 2 pages - are these intended for connecting a battery bottle?

Thanks

Just go for 36v, I went for 43v, I have a motor that I won’t be able to use because bafang needs at least 1.5 months to produce the new 43v battery…

 

[mike_kelly]

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

 

[Kenk3589]

damn I just checked why my bike was creaking.. and half the bolts attaching the motor to the frame has already fallen off. Everyone should make sure to loctite every single one of those screws..

Anyone know where I can get extra motor attachment screws?

 

[Myalteregohamish]

This is the same thing that happened on my canyon Torque:ON

 

[TCFlowClyde]

damn I just checked why my bike was creaking.. and half the bolts attaching the motor to the frame has already fallen off. Everyone should make sure to loctite every single one of those screws..

Anyone know where I can get extra motor attachment screws?

Depends. I lost my main pivot bolt screw (flat head socket screw = fhss) and speciality beveled alloy washer the second ride. Fortunately, a generic M6 fhss and M8 alloy spacer could be purchased at local Hardware (ACE). The OEM replacement is still weeks away with the new warranty front triangle.

To your issue on motor mount hardware. I think they're M4 fhss for two motor mounts with the really thick black alloy custom spacers/alloy thru-bolt-like double-ended female threaded shaft bolt (defts bolt). The bigger is a M6 fhss, black alloy spacers, and steel defts bolt.

Caveat. I'm going from memory of sizes for screws. Check your remaining bolts to confirm.

If the spacers are there with defts bolts, fortunately the fhss should be easy to find. Steel defts could be sourced too. But the alloy spacers are most challenging and might have to be machined if you want them faster than from SZZS.

 

[Kenk3589]

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.

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?

 

[spokémon]

So, just a little extra weight to shave off then...makes sense.

Not only that, if you had a seatstay bridge, you probably wouldn't be able to fit a 210x55 shock with a sweet 165mm rear travel

 

[TCFlowClyde]

Not only that, if you had a seatstay bridge, you probably wouldn't be able to fit a 210x55 shock with a sweet 165mm rear travel

@thaeber mentioned this clearance way back in January...I just didn't understand it until much later. He has an engineer's eye!