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

[TCFlowClyde]

¿Alguien ha comparado el rendimiento de un amortiguador de muelles con uno de aire en este cuadro? ¿Cuál recomendarías?

@calvintys races DH and has several CEF50 builds using both high-end coil and air-shocks.

 

[calvintys]

I never try before air shock as my group all use Ohlins coil from start. Several of my friend were impress with my CEF50 Ohlins front + Back feel. Apart from the motor its a little low power else this bike will be Prefect. Too bad on race, it fall under full power bike category NOT SL category. So i have struggle a little.

 

[atlet]

Update. They said that the problem was the motor so they arranged a warranty claim. I send motor to Bafang for repair.

Update: I received a new motor. Now it's a different bike. The original motor was faulty.

 

[TCFlowClyde]

Damn! SZZS was putting out their 36 V extender battery(280? Wh) next month.

Was $245 USD. X .34 = $83.3 more for $333.3 total .

Granted still cheaper than the big boys like Specialized and Trek etc...but still!

Thanks very stable genius!

View attachment 157340

Well, now there's a ludicrous 104% US tariff on most Chinese goods. So, currently a whopping $245 x 2 + .04 = $509.6 USD!

Edit update: So, technically 50.4 % of us DIDN'T vote for the current autocratic administration. Our system isn't ranked choice voting unfortunately, and has an antiquated electoral college system (all-or-nothing winner). Therefore, the 49.6 % who did vote for a Big Daddy economy gained political control...we're now a cross between a Kleptocracy and Kakistocracy...neither reflect liberal democracy sadly! And thus, the tariff chaos! "Elect a clown, expect a circus!" (1.0 & 2.0)

Edit #2. Tariff now 125%. Add another $45+ USD..

Let's see if we hit 200% by tomorrow.

We has got a drunk, unmedicated, mentally-ill captain steering the ship directly into a category 5 hurricane.

 

[TommyR]

Well, now there's a ludicrous 104% US tariff on most Chinese goods. So, currently a whopping $245 x 2 + .04 = $509.6 USD!

Edit update: So, technically 50.4 % of us DIDN'T vote for the current autocratic administration. Our system isn't ranked choice voting unfortunately, and has an antiquated electoral college system (all-or-nothing winner). Therefore, the 49.6 % who did vote for a Big Daddy economy gained political control...we're now a cross between a Kleptocracy and Kakistocracy...neither reflect liberal democracy sadly! And thus, the tariff chaos! "Elect a clown, expect a circus!" (1.0 & 2.0)

Preach!!

 

[mike_kelly]

Gaskets are in for m820! Get them while you can!
"

The M820 gaskets have arrived.
If you are from the US, please order asap and choose DHL/UPS for shipping; this Friday is the last day we ship to the US by DHL/UPS/Fedex.
We will stop US shipping from next week temporarily for small parcels. Larger parcels for motors and batteries are still available but freight would be increased due to the US tariff policy.
For M820 gaskets, please order from here https://www.greenbikekit.com/bafang-8fun-motor-parts/m820-m800-motor-parts/bafang-m820-g532-motor-gasket.html
Best Regards!
Ms Anna Lee
www.greenbikekit.com
[email protected]"

 

[TommyR]

Maybe I missed it, but is this gasket a known failure point?

 

[TCFlowClyde]

Maybe I missed it, but is this gasket a known failure point?

It breaks easily (almost 100%) once the motor is first opened to overhaul it for a routine lube or repair. Otherwise, it seems to seal appropriately.

 

[TommyR]

10-4! I guess I'll snag one just in case. Thanks!

 

[mike_kelly]

Tom and myself, as well as all the other early adopters have put some miles on our motors. I for one want to take care of mine so it lasts as long as possible. I tried pulling mine apart when I first got it and added more lube but the gasket ripped because it is just made of paper. I glued mine back together at the time.
Hongkong is not going to ship any small parcels via mail to US starting in a few days.

 

[BenCatalan]

It breaks easily (almost 100%) once the motor is first opened to overhaul it for a routine lube or repair. Otherwise, it seems to seal appropriately.

How often would you recommend to lube the engine, vs a secondary transmission (which depends on dry / wet conditions, hard use…)?

 

[TCFlowClyde]

How often would you recommend to lube the engine, vs a secondary transmission (which depends on dry / wet conditions, hard use…)?

Good question honestly. I'm in the desert (very dry) and will run the motor hot often 90°F and above...so shorter lube intervals for me.

This was the case for my Bafang M600-120Nm at 2,200 miles...gained power back like new...which was dramatic.

I've heard mechanics recommended 1750-3000 miles as a rule of thumb. I'm about 2000 miles now....I'm hearing a little more gearring chatter, so mine is probably overdue.

 

[TommyR]

Hey y'all,

I've only logged a little under 100 miles on my CEF50 since I built it up. And while I've been MTBing for decades, e-bikes are entirely new to me. I have a couple questions and am hoping y'all can help...

1. I thought our Bafang systems were torque sensing, i.e. if you apply more torque through the cranks, the motor will provide more torque. However, that doesn't appear to be the case. It seems that when the motor kicks in, it just provides a fixed level of power (based on my setting). It seems like it's all or nothing. Is this system torque sensing or not?

2. I have the BESST Pro tool, but have some questions. The parameters are pretty straightforward and I've altered them to my preferences. However, I have a question about the "acceleration" feature and what it changes. Is this essentially the steepness of the curve from zero to full power (full power being defined by the bar-mounted controller)? For example, at acceleration level "1", maybe it takes 2 seconds of pedaling to reach full power and at level "8", it only takes 0.5 seconds. Is that accurate? I've tried both ends of the range, but didn't notice a difference on the trail. Despite the image, I have it back up to "8" and will try it again today.

3. At lower RPM/cadence, the motor seems very unresponsive. Once up to speed it feels as expected. But if my cadence drops a bit going up a climb, it gets disproportionately difficult to pedal....like the motor isn't helping much. I've changed my riding style to downshift more than usual. I've also experimented going from my 155mm cranks back to 165mm to get more leverage, but I don't think it really made a difference. It seems like there is a minimum cadence for the motor to kick in and that minimum may be higher than my typical cadence. This would be odd because my cadence is usually pretty high.

Anyway, sorry for the novel, but any help would be much appreciated!
Tommy

 

[TCFlowClyde]

Well in general, the M820 motor is definitely a higher cadence motor as compared to my M600-120Nm. I'd say climbing in turbo takes 85-95 RPMs with the smaller M820. I'd guess 74-85 RPMs with my M600. RPMs are based off my stationary spin bike I ride 3x a week where I can see them in real time, so it's my comparative perspective and best guess.

I run 155 cranks and a 32t chainring (1-12 spd) on my M820, and 152 cranks and a 32t chainring (12 spd) on my M600.

Also, I found my torque was optimized when my dropper was used as a topper (another few mms set extra raised like on an XC analog maybe) for the M820 motor, so I could keep my cadence up consistent (more efficient) in boost climbs... otherwise it would stop and I'd wait a few seconds to restart at that same power level.

So, I figured it's a smaller motor. Plus, i have lost the my own fitness power a little from using full powered the previous 4+ years and atrophied since the analog days. And I'm heavier now too!

One reason, I like the M820, got to hustle up those climbs sometimes. I missed that feeling of accomplishment when using M600 and certainly from my real big M620-160Nm motor on my phattie Emtb.

Don't know if any of this helps, but this seems close to how a m820 is supposed to perform.

 

[mike_kelly]

After my first eMTB, way back in 2022, which was cadence there is no question that I feel the torque sensor working. With the old BBSHD if you had it in the highest assist and you just turned the pedals the bike would jump out from under you. I don't remember any difference between my Orbea Rise and my CEF50. The RIse was designed to be a assisted pedal bike. Mean from day one the design limited the motor output to increase the length of a ride therefore forcing the rider to add to the power.

 

[Charly]

Hi, I have about 10 days to choose between 700Wh or 480Wh in 48V. What autonomy are you offering? I'm going to use it for XC marathons. I weigh 74 kg and I'm in training.

 

[TCFlowClyde]

Hi, I have about 10 days to choose between 700Wh or 480Wh in 48V. What autonomy are you offering? I'm going to use it for XC marathons. I weigh 74 kg and I'm in training.

Sounds like you want to weigh the least as you can possibly be?

I think the battery weight difference between the 480 Wh and 700 Wh is roughly 2-3 lbs/1-1.3 kg.

You could buy both to see which serves your needs better? Really, only you can answer your question.

 

[calvintys]

Base on my experience, go for 700wh 48v, my bike it's 480wh and I am running out of juice regularly. My first 6 month 480wh it's OK but now 480wh it's too little.

 

[Charly]

Sounds like you want to weigh the least as you can possibly be?

I think the battery weight difference between the 480 Wh and 700 Wh is roughly 2-3 lbs/1-1.3 kg.

You could buy both to see which serves your needs better? Really, only you can answer your question.

I could leave the bike at about 16 kilos with the 480 Wh battery and add for long trips the external battery that they will launch on May 10th, 280 Wh from the factory.

 

[Charly]

Base on my experience, go for 700wh 48v, my bike it's 480wh and I am running out of juice regularly. My first 6 month 480wh it's OK but now 480wh it's too little.

What kilometers did you do and the gradient with the 480wh 48v battery and how much weight did you lose with that battery and now with the 700wh one?

 

[Charly]

S size frame only, plus 48v motor frame and both 480wh and 700wh batteries in 48v

 

[calvintys]

What kilometers did you do and the gradient with the 480wh 48v battery and how much weight did you lose with that battery and now with the 700wh one?

On average with around 430w motor output power, I get around plus 30km with evelation climb 1000. Battery level should be below 15%. My bike weight 19.5kg using all high parts, xo t type groupset, 1.65kg wheelset, oneup cockpit, ohlins coil shock , ohlins rxf38 m.2 n rear cushcore.

 

[Charly]

On average with around 430w motor output power, I get around plus 30km with evelation climb 1000. Battery level should be below 15%

That's a lot of power, I usually go in E and T mode

 

[brbr]

I did 37km with 1050m d+ this week mostly in E/T/S and S+ in the last kilometers. I went back home with around 30% of battery. I have the Bafang battery BTF014 410Wh.

 

[calvintys]

That's a lot of power, I usually go in E and T mode

My first 6 months, I usually on E or T but now e or t kind of little slow n boring for me. Even i was on 430w , my cadence it around 90 n we pedal non stop 30km ride.

 

[402.ac]

Do the frames with normal cable routing have a headset for a 1.5" or 1.8" fork?

 

[Dado]

None. I'm hoping Bafang will do a firmware update for the M820. Max is still 75 Nm.

When Bafang first launched the lightweight motor a few years ago, they advertised as 75Nm max torque, but also had a mysterious short superboost mode...a few us here in jest just picked 85Nm as a theoretical max, in part to be categorized as a small, lightweight, truly 85Nm full power motor.

My desire was that someone at Bafang was listening (maybe reading this thread) and would put out a firmware update to compete with updates from Brose, Bosch, and Shimano, who are in turn dialing up their torque to compete with the DJI-Anivox 120Nm.

But I think Bafang has so much else going on with their other motors, such a firmware update is unlikely. Bafang seems fairly insulated from consumer feedback directly.

Bottom line: there is NO superboost 85Nm power mode firmware update planned that I'm aware of.

C'mon Bafang, give us an 85Nm superboost upgrade!

And they went exactly other way.
lowered 43V version to 10A and 48V to 9A.
I guess to lower the stress on a drivetrain. And not to have so much warranties.

 

[mike_kelly]

Do the frames with normal cable routing have a headset for a 1.5" or 1.8" fork?

All the frames, as far as I know, are 1.5 tapered

 

[TommyR]

Yesterday I put almost 22 miles on my bike. 16 miles were on pavement (Boost) and the rest were on a trail (S+). While on the pavement my display was showing a pretty consistent 250-350 watts of output (spiking to over 400 that I saw). Cadence was likely 80 rpm or so. The route was rather flat with no significant grades, except........

There's a climb up to my street right at the end of my ride. I downshifted and I would estimate my cadence was at least 90 rpm, but likely higher. Power output was a mere ~170 watts! Keep in mind the system was in Boost mode. Correct me if I'm mistaken, but I expect to have more assistance in such a situation. Is something wrong with my bike?

FYI, the system otherwise worked as I'd expect and I received no feedback from the system that it was in any kind of thermal overload or de-rate situation. In other words, it wasn't overheated oer reducing the motor's output or anything like that.

 

[mike_kelly]

If the motor overheats it reduces assistance with no other indications. Boost on a steep hill can do that.