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

[calvintys]

Just confirmed that loctite 603 is used on headset cups. Reading on how to remove it, seems like you need high heat of 250c, which is not possible with the carbon fiber.

Even if it possible ur paint will be gone.

 

[TCFlowClyde]

Just confirmed that loctite 603 is used on headset cups. Reading on how to remove it, seems like you need high heat of 250c, which is not possible with the carbon fiber.

Oh wow! That's unusual.

Can the frame be purchased without the glued bearing cups like the original?

Or even make a warranty replacement if problems exist with them in if still creating problems. It sucks but if the SZZS headset won't eventually work?

 

[calvintys]

Anyone try to add headset shim to SZZS headset? What size you guy put ?

 

[92se-r]

Anyone try to add headset shim to SZZS headset? What size you guy put ?

View attachment 137796

Yes i put 2 0.5mm shims. It helped clunking drastically. The top cap was bottoming out on race without shims. However on very large hits i will still get occasional clunk. Not sure if its cables inside. I need to tear it apart and put foam on cables. I might try adding another shim to see also.

I did notice the bearing seemed to allow a lot of inner race movement. I bought another bearing and it still has movement. I just think this design is not great and the bearing quality is not great.

 

[calvintys]

I have the same problem too with 1mm spacer and I get annoyed by the headset sound

 

[voigtkampff]

Just confirmed that loctite 603 is used on headset cups. Reading on how to remove it, seems like you need high heat of 250c, which is not possible with the carbon fiber.

on my frame the top cup indeed bears marks of glue, however the general loosness and knocking in the headset caused that the cup became loose and falls out without any special treatment. so you know, try jumping a few times with preaload screw nod fullt tightened and it may fall out too...

anyway, my usual method of removing the cups is: take a wooden stake and rubber hammer, insert the stake through the other side opening and hit it few times with a hammer. usually it comes out with ease.

 

[voigtkampff]

I have the same problem too with 1mm spacer and I get annoyed by the headset sound

yup, same here. 1mm spacer (4x0.25mm) helped but it still becomes a bit loose after day of jumps. I have a hypothesis that this is caused by the fact the top race is made from PTFE which has very low friction compared to the usual metal ones and allows for minor movements even when tightened to levels which usually would cause increased wear to the bearings

 

[92se-r]

on my frame the top cup indeed bears marks of glue, however the general loosness and knocking in the headset caused that the cup became loose and falls out without any special treatment. so you know, try jumping a few times with preaload screw nod fullt tightened and it may fall out too...

anyway, my usual method of removing the cups is: take a wooden stake and rubber hammer, insert the stake through the other side opening and hit it few times with a hammer. usually it comes out with ease.

Have you ever removed headset cups with loctite 603 or any other bearing retainer? Ive only removed headset cups from aluminum frames which used anti seize or grease.

 

[voigtkampff]

Have you ever removed headset cups with loctite 603 or any other bearing retainer? Ive only removed headset cups from aluminum frames which used anti seize or grease.

fortunately (?) I didn't have to as it fell out on its own.

according to the docs loctite 603 is for glueing metal to metal (netting or polymerization is initiated by presence of metal ions), so this might be the reason why it became loose so easily with my top cup. I think trying to delicately knock it out with a rubber hammer won't hurt, after all this frame is designed to carry around my fat ass during the jumps and carbon fiber is typically more durable than aluminium layer of the same width

 

[92se-r]

fortunately (?) I didn't have to as it fell out on its own.

according to the docs loctite 603 is for glueing metal to metal (netting or polymerization is initiated by presence of metal ions), so this might be the reason why it became loose so easily with my top cup. I think trying to delicately knock it out with a rubber hammer won't hurt, after all this frame is designed to carry around my fat ass during the jumps and carbon fiber is typically more durable than aluminium layer of the same width

Did you replace with new or just put it back in?

 

[voigtkampff]

Did you replace with new or just put it back in?

for the time being I put it back in but I'm planning to replace it with Nukeproof ZS56 headset waiting in my parts bin for a suitable moment to make cut outs in the head tube sides

 

[92se-r]

for the time being I put it back in but I'm planning to replace it with Nukeproof ZS56 headset waiting in my parts bin for a suitable moment to make cut outs in the head tube sides

How loose was the cup when you pressed it back in?

 

[ficorama]

Hello everyone. the bike is assembled, some other small things, then on to the real ride.
I did a firmware update. firmware CRX30PC3615E102003.3 works for me. and with CRX30PC3615E102003.2 it doesn't recognize my battery.

first impressions, the engine has a lot of power. only in B mode, after sudden pedaling, the engine shuts off, then starts again after a few meters. and when it rotates constantly, everything is ok, only when the pedal is pressed hard, the assistance turns off.

the weight is about 20.5 kg, I'm adding some other little things, so I hope it won't be heavier than 21 kg.

Frame XL
battery DIY 11s3p 21700 lg 5800mah cells.
fork Zeb 29 select 170mm
Shock suntour triair 210x55 with offset bushing. ete length with the offset bushing is 214mm, so I left the stroke 55mm.
Wheelset Mavic e-deemax mullet s30-s35
Tires prowall casing
front pirelli scorpion enduro s 29x2.4
rear in arrival pirelli scorpion enduro s 27.5x2.4
Cassette 12 spd. 11-52 aliexpress
Shifting Sram gx
brakes Hayes dominion a4, 220mm rotor

 

[voigtkampff]

How loose was the cup when you pressed it back in?

I could easily remove it and press it back with my bare hand or just turn the bike upside down and let the gravity do the work

 

[voigtkampff]

folks, my evening flash ride, 25km; 500m elev. gain almost entirely in B mode, 22% of 480Wh battery left. seems like it's eating the battery like a hungry hog. does this battery consumption look ok to you? I was hoping I could squeeze more from this battery...

 

[mike_kelly]

from JimLee's conversation with Bafang.
"About the DIY battery, lots of peoples want the bigger battery, 720wh, 840wh, 960wh, the more the better,
but please note,
1. This is an electric assist bicycle, electric energy is only auxiliary and should not be the main force, Use your feet to move the pedals, not just sit there.
2. We talked with the bafang designers, they not suggest the bigger battery more than 500wh for M820 motor, That is, the full electric mode for two hours; high current output for a long time may cause the motor to overheat, which involves the effective conversion of energy of a motor, and they are still being resolved."

 

[voigtkampff]

from JimLee's conversation with Bafang.
"About the DIY battery, lots of peoples want the bigger battery, 720wh, 840wh, 960wh, the more the better,
but please note,
1. This is an electric assist bicycle, electric energy is only auxiliary and should not be the main force, Use your feet to move the pedals, not just sit there.
2. We talked with the bafang designers, they not suggest the bigger battery more than 500wh for M820 motor, That is, the full electric mode for two hours; high current output for a long time may cause the motor to overheat, which involves the effective conversion of energy of a motor, and they are still being resolved."

hey bafang engineers, where tf is my friggin ROCKY mode?! xd

 

[TCFlowClyde]

hey bafang engineers, where tf is my friggin ROCKY mode?! xd

Too true. But, I rather have the boost continuous if needed. I rode the the Fazua 60 using their 10 sec super boost mode. Way too short to be practical, even on super short climbs.

I haven't quite used the 820 boost mode for two hours (close in rolling hills) just for a one-time test when I first got it, but I thought the bigger battery was sure nice to have for extra range security. I'm glad I went bigger for my regular riding needs!

However, give me futuristic solid-state 1000Wh battery 8 lbs lighter and safer, I'd be much happier and feel even less range anxiety. C'mon EV chemistry...bring solid-state to market sooner rather than later...and cheaply. Also, don't count on Elon to make it affordable.

 

[92se-r]

from JimLee's conversation with Bafang.
"About the DIY battery, lots of peoples want the bigger battery, 720wh, 840wh, 960wh, the more the better,
but please note,
1. This is an electric assist bicycle, electric energy is only auxiliary and should not be the main force, Use your feet to move the pedals, not just sit there.
2. We talked with the bafang designers, they not suggest the bigger battery more than 500wh for M820 motor, That is, the full electric mode for two hours; high current output for a long time may cause the motor to overheat, which involves the effective conversion of energy of a motor, and they are still being resolved."

This is why I stand by my statements regarding 48v running way cooler than 36v and will lead to better reliability and longevity of components. This is a full size motor packaged in a low power casing. The math doesnt lie. Say at 500w, the 48v system has roughly 78% less heat.

 

[calvintys]

folks, my evening flash ride, 25km; 500m elev. gain almost entirely in B mode, 22% of 480Wh battery left. seems like it's eating the battery like a hungry hog. does this battery consumption look ok to you? I was hoping I could squeeze more from this battery...

Shift it down to S+ mode and cycle high cadence, the higher your bike cadence the less power the motor consume , I notice my battery drop quality when I turn lazy n pedal with a slow cadence.

 

[mike_kelly]

This is why I stand by my statements regarding 48v running way cooler than 36v and will lead to better reliability and longevity of components. This is a full size motor packaged in a low power casing. The math doesnt lie. Say at 500w, the 48v system has roughly 78% less heat.

The m820 is not a full size motor and I don't buy the 78% less heat at 48v. The heat affecting the motor is dependent on the heat sinking. You can't calculate the potential heat savings without taking into consideration the removal of heat.
Just compare the weight of the M820 compared to one of it's full size siblings.

 

[92se-r]

The m820 is not a full size motor and I don't buy the 78% less heat at 48v. The heat affecting the motor is dependent on the heat sinking. You can't calculate the potential heat savings without taking into consideration the removal of heat.
Just compare the weight of the M820 compared to one of it's full size siblings.

My old e8000 motor puts out 75nm of torque. Ep8 does 85nm. Whats a full size motor to you? M820 will put out 85nm.

Levo sl gen1 does 35nm. Gen2 does 50nm. Fazua does 60nm i think. These are the lightweight motor specs. Lightweight means smaller heat capacity.

The math doesnt lie, whether you want to believe it or not. The main source of heat in your system is motor winding resistance and mosfet switching losses. Do the math at 500w. P=i^2*r. The current is squared. The heat generated is in power. That never changes regardless of the heatsink. The heatsink is just there to prevent too high of a temp rise on the motor and motor controller components.

The heatsink is the case. That is the only way heat is removed. Unless you are telling me the housing is different between the 36v and 48v versions. Regardless my point still stands, regardless of the heatsink, the 36v system needs to remove significantly more heat from the motor due to the increased current.

 

[mike_kelly]

neither the Shimano e8000 nor the EP8 is a full size motor. The Bafang 620 is a full size motor.
The effect of the heat and how it is removed does make a difference. It would make no difference how much heat was produced if it was all removed by cryo cooling etc. The heatsinking is there to establish the designed heat tolerance.
All engineering is a balance between evils. You design a jet to handle in the left half plane and then you pull it back into the right half plane to make it stable again. In a three phase motor you choose a kv for the motor voltage decide on what power you want and make choices in the winding and the core then you design a controller to drive it. Then it melts and you design some cooling and back a forth.
If the heatsinking is adequate to cool a 36v motor and you are not using it outside the boundary conditions set by the designers, like using boost for a long climb, then 48v is going to do nothing at all if you don't change the winding size.
If you use the M820 out of the design boundaries then you are on your own.
There is no magic in a 48v or 85v motor.

 

[92se-r]

neither the Shimano e8000 nor the EP8 is a full size motor. The Bafang 620 is a full size motor.
The effect of the heat and how it is removed does make a difference. It would make no difference how much heat was produced if it was all removed by cryo cooling etc. The heatsinking is there to establish the designed heat tolerance.
All engineering is a balance between evils. You design a jet to handle in the left half plane and then you pull it back into the right half plane to make it stable again. In a three phase motor you choose a kv for the motor voltage decide on what power you want and make choices in the winding and the core then you design a controller to drive it. Then it melts and you design some cooling and back a forth.
If the heatsinking is adequate to cool a 36v motor and you are not using it outside the boundary conditions set by the designers, like using boost for a long climb, then 48v is going to do nothing at all if you don't change the winding size.
If you use the M820 out of the design boundaries then you are on your own.
There is no magic in a 48v or 85v motor.

The m620 is an anomaly, not the norm. Its sales numbers arent even a blip in the grand scheme of things. Its readily accepted that EP8 and bosch cx motors are both full power 50+ lb ebikes at 85nm of torque. Ready any ebike reviews that reference this.

Ive never said anything about operating outside designer operating conditions. Ive only ever said 48v runs significantly cooler than 36v and showed you the math why. Are you saying you still disagree with the math?

And straight quoted from your post, the Bafang engineers dont recommend long durations in boost. Why? It is thermally limited by the heatsinks ability to remove heat. What does that translate to in real world situations? You can probably ride longer before you hit thermal limit in boost.

Running cooler is never a bad thing with electronics. It absolutely lowers failure rates.

 

[TCFlowClyde]

36V v. 48V heat dissapation popcorn debate.Oh! Do GOOOO-on!

 

[Yozha]

First impressions, the engine is very. Only in mode B, abruptly after turning on the pedals, the engine stops, then after a few meters starts again. and when rotating constantly then everything is ok, only with a strong pressure on the pedal the help turns off.

I am concerned about your mileage information. I sold a Cube bike with 500Wh battery and Bosh CX motor and paid for a Bafang 820 with 700Wh battery in the hope that I can increase the mileage of the bike by 30 percent.... Do you think I can get what I want?

 

[ficorama]

I am concerned about your mileage information. I sold a Cube bike with 500Wh battery and Bosh CX motor and paid for a Bafang 820 with 700Wh battery in the hope that I can increase the mileage of the bike by 30 percent.... Do you think I can get what I want?

I can't answer you. I just assembled the bike. I haven't even been on a test drive yet.

 

[voigtkampff]

Shift it down to S+ mode and cycle high cadence, the higher your bike cadence the less power the motor consume , I notice my battery drop quality when I turn lazy n pedal with a slow cadence.

Thanks, could you elaborate on "my battery drop quality when I turn lazy", I couldn't quite get it and this sounds interesting.

Just to explain, this was my one and only ride in B mode, with the intention to record the movie of my battery level indicator dropping by large values as I wrote few posts earlier, to demonstrate this to SZZT. Still the range was disappointing. Usually I ride in E/T mode with range of ~80km (which seems like quite low too). My typical cadence is in the range of 80-90 rpms, so I guess it's not that low. Even during my B mode spree I keep this cadence because that's what I'm used to, so I don't think cadence is an issue here.

 

[calvintys]

Thanks, could you elaborate on "my battery drop quality when I turn lazy", I couldn't quite get it and this sounds interesting.

Just to explain, this was my one and only ride in B mode, with the intention to record the movie of my battery level indicator dropping by large values as I wrote few posts earlier, to demonstrate this to SZZT. Still the range was disappointing. Usually I ride in E/T mode with range of ~80km (which seems like quite low too). My typical cadence is in the range of 80-90 rpms, so I guess it's not that low. Even during my B mode spree I keep this cadence because that's what I'm used to, so I don't think cadence is an issue here.

When I turn lazy mean I pedal.on a very slow cadence , when cycle u will notice the m920 motor 3 difference sound stage. The beginning sound stage will consume the most battery and the third stage consume less power.

 

[masahirov]

I could easily remove it and press it back with my bare hand or just turn the bike upside down and let the gravity do the work

Oh, so there are people who have the same problem as me. My headset can be easily attached and detached by hand.

Naturally, noise and vibration come from the head cup, but we have been able to reduce this considerably by placing a piece of paper between the head tube and the head cup.

As this was my first e-bike I was a bit worried about the motor and battery, but I never expected to end up having trouble with the frame.