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

calvintys

Active member
Sep 12, 2023
255
256
Malaysia
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.

View attachment 131433 View attachment 131434


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? View attachment 131438

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.
Nice comparison result, i am curious how does CEF50 geometry in term of downhill compare to your Kenevo SL. My initial choice was Trek EXE or Kenevo SL but end up getting CEF50 because bike industry price are at peak point and its heading down now soon.

the cef50 BB height its a little high, i am thinking of using offset bushing to lower it by 10mm.
 
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Myalteregohamish

Active member
Jan 4, 2023
294
240
Vancouver, WA
It’s a trade off. I prefer the CEF50, it’s more stable on the downhill. That said I notice mainly the stanchions between the 36 vs 38. This causes the bike to feel a bit more laterally still. The KSL is on 36 so downhill it lacks the planted feel of the CEF50.

The suspension although only 150, Feels deeper especially after I took out spacers. Now the midstroke feels much longer. The KSL feels more lively and takes more work to get it planted.
 

patdam

Well-known member
Jan 17, 2019
902
601
france
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'm also agree with you. For me the M820 is a perfect motor to build an 'light' bike for heavy rider (with a few physical capital anyway). but what is your opinion in regard of battery ? do you think 700 is useful or 500 enough ?

As M820 request more physical effort on hard climb ( + 20%) and it consume lot off less than the M510 in max power (+- the 3/4 of that able to provide the M510), personally i will too tired to use the last 50% of the battery. and as i think i can do 2000 D+(not done for the moment) with the first 50%, it's enough for me.
 
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calvintys

Active member
Sep 12, 2023
255
256
Malaysia
It’s a trade off. I prefer the CEF50, it’s more stable on the downhill. That said I notice mainly the stanchions between the 36 vs 38. This causes the bike to feel a bit more laterally still. The KSL is on 36 so downhill it lacks the planted feel of the CEF50.

The suspension although only 150, Feels deeper especially after I took out spacers. Now the midstroke feels much longer. The KSL feels more lively and takes more work to get it planted.
Which model of 36 are u using for your KSL. If your its current model 36 performance or factory with air release button at the back of lower leg shoulden be much different since yiur body weight only 80 plus kg. Both 36 and 38 has a similar smooth feedback or planted.
 

Myalteregohamish

Active member
Jan 4, 2023
294
240
Vancouver, WA
The 36 is fox performance. I don’t think there’s a release on it. You have to do that little zip tie trick. Yesterday I got the fork feeling pretty good. Much more planted and confident over chattery loose sections. I was pretty happy with it.
 

Neeko DeVinchi

E*POWAH Elite World Champion
Dec 31, 2020
1,033
1,376
UK
In a months time will you be able to tell us more about this motor, that I'm hopeful is the m620 +10. It's been very quiet since it's announcement
You mean the M630 Motor right?
Yes, I'll be covering the system in 2024👍🏿
 

TCFlowClyde

Active member
Feb 26, 2022
1,347
870
Mesa, AZ
You mean the M630 Motor right?
Yes, I'll be covering the system in 2024👍🏿
Ahhh...the M630, thanks for clarification.

I have a M620 full sus fattie. Sure it's fun, but more like "moto" than an mtb.😁 I use the old Sram EX1 8 spd. drivetrain to handle the high torque and give longer chain wear. It's my understanding that the M620-160 Nm was made for cargo, street ebikes more than traditional trail, E-mtb. But makes sense for fatties like mine that go in sand and snow well, as their more higher torque conditions

Overall, the power is too much for singletrack in a sense. I keep it down in low power modes of 1, 2, and 3 out of 5 for 750Wh "sport mode" out on my regular trails. Crazy climbing ability. It's just the opposite end of the Bafang spectrum compared to their M820.

Side note: Bafang, or "Big Bang" in general should be thought of as affordable, reliable, big power if nothing else. That's why the M820 works well for the "SLs". They over juiced the traditional category, for the better!

For the M820, I use power modes 3,4,5 and the M600 uses 2, 3, 4, on all in the same trails.

My 620 build (premium spec and full carbon and carbon wheel set) is 68 lbs! Too heavy and just not nimble in comparison to an analog mtb (or full sus fattie mtb in this case).

I like the M600 much better. And at 58 lbs, closer to a analog. But at 48 lbs the M820, is EVEN more close to analog nimbleness. I'd luv to ride the M820 at 38 lbs! (All weights are "wet" meaning fully load with water bottle cage, heavier tires, foam inserts, sealant, pedals and if course trail handlebar bell 🔔).

Since the M820 delivers 75 Nm, it's the lowest I'd drop down to. I look forward to future battery chemistry, saving another 10 lbs off my CEF50-enduro edition would really be the ultimate sweet spot!!!

The goal: Feather light🪶, with good power💪, and greater range⚡!
 
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TCFlowClyde

Active member
Feb 26, 2022
1,347
870
Mesa, AZ
How long do yo ride for, an estimated average? And ft gained also on average.
On average about 16-20 miles. 1.5-2 hrs.
My terrain consists chunky foothills, short, steep ups out of washes and ravines, and soft, loose rolling flats.

Quick-burst power for my area mostly. Nothing huge like the Alps or Rocky Mtns or coastal mtn ranges like on the west coast of the US. Big, mountain climbs, when I go to California to ride, I'd need more battery on the CEF50 for those long, protracted, adventurous ascents! Or I would just ride my M600 with the 1000 Wh battery. 👊
 

Myalteregohamish

Active member
Jan 4, 2023
294
240
Vancouver, WA
On average about 16-20 miles. 1.5-2 hrs.
My terrain consists chunky foothills, short, steep ups out of washes and ravines, and soft, loose rolling flats.

Quick-burst power for my area mostly. Nothing huge like the Alps or Rocky Mtns or coastal mtn ranges like on the west coast of the US. Big, mountain climbs, when I go to California to ride, I'd need more battery on the CEF50 for those long, protracted, adventurous ascents! Or I would just ride my M600 with the 1000 Wh battery. 👊
You’re reading my mind.
 

TCFlowClyde

Active member
Feb 26, 2022
1,347
870
Mesa, AZ
You’re reading my mind.
That's why the CEF52 would be attractive...elevation gain with the EP8-85NM. Like you said more efficient for the power tradeoff. And you only gain a pound moving up the full powered motor with 720 Wh battery! But then if the EP801 is really that efficient, you wouldn't need the extra battery extender (2-3 lbs).

So overall with the 52 you gain a pound for the EP8 motor weight, but don't have to add more battery (theoretically) and it's additional weight. So win/win for the CEF52-85Nm!

However to be fair, the smaller, lighter M820 has less surface area and could be added to a lower profile frame design, and stealthier, more aesthetically pleasing, pose like the Forestal Siryon (front triangle part). Although, I'd rather have it look like the Transition Relay (PNW version) instead!🤟

More to my point. I think the engineering limit is 75 Nm for the M820's lighter, more compact build over the EP8. For example, the TQ50 and Fazua60 would have to grow larger to manage the heat and power output I suspect if it was to get to 75 Nm. I'm guessing this why the M820 is kind of a unique engineering feat!
 

TCFlowClyde

Active member
Feb 26, 2022
1,347
870
Mesa, AZ
Any update from Linda on this? I’d heard that they’re waiting on batteries.
Not from Linda. All my info was from Eason Li at SZZS.

Eason was saying that the 720 Wh was being used in Japan. I don't know If that meant simply configure their battery with the EP8. I assume that as long as the connectors are compatible with the motor, a third party battery should be good to go!

Here's what he told me last week:👇
Screenshot_20231230-173122.png

I didn't inquire further due to lack of interest. Also, why Mike started the CEF52 thread to direct traffic over there.
 

92se-r

New Member
Dec 23, 2023
161
60
United states
For those of you running mullet, do any of you run a 170mm fork? Do you know what the bb height is with a 160mm fork vs a 170mm fork on a mullet setup?

Also, has anyone successfully run a Fox Float X, especially on a size small?
 

calvintys

Active member
Sep 12, 2023
255
256
Malaysia
For those of you running mullet, do any of you run a 170mm fork? Do you know what the bb height is with a 160mm fork vs a 170mm fork on a mullet setup?

Also, has anyone successfully run a Fox Float X, especially on a size small?
You should not have any problems if u wanted to mullet as its BB height are pretty high 360mm and if u convert it mullet u be getting somewhere 342 bb height if u are using 160mm fork. As for ur float x will fit perfectly. If you thinking for a new frame, contact linda to v2 cef50 as its coil shock competible
 
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92se-r

New Member
Dec 23, 2023
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United states
No, if you have two 500whr batteries they have the same power output at 48v or 36v.
That may be true for instantaneous peak power, since the motor controller will have peak current limits. I would wager a guess that for the sake of production efficiency, the 36v, 43v, and 48v versions of the m820 motor are exactly the same with just different firmware between the 3 for voltage cutoff and power limits to protect the battery below certain soc levels. If that is true, 48v packs will probably see longer durations of peak power on the m820 due to not hitting thermal protections on the motor and motor controller. I^2r losses between 36v and 48v are very significant since current is squared. Say for a given 500w peak load, you would have to dissipate almost double the heat load at 36v with the same metal case compared to a 48v system. Again, this is with the assumption that the bafang motor construction is the same between 36v versions and 48v versions.
 

mike_kelly

Well-known member
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Aug 11, 2022
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Yes if the company does not take advantage of the opportunities to reduce winding size etc etc then the differences can be negated. Economy of scale rules.
 

92se-r

New Member
Dec 23, 2023
161
60
United states
Yes if the company does not take advantage of the opportunities to reduce winding size etc etc then the differences can be negated. Economy of scale rules.
I just cant imagine the volume is there to optimize for 48v. If there are no weight deltas between 36v and 48v, they most likely did not imo. China usually designs to the lowest common denominator to hit a price point.
 

mike_kelly

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Well if they made them the same, for economy of scale, it would have to be for the 36v which would require higher ampacity wires. It would be interesting to calculate what the weight savings would be for the 48v motor.
 

92se-r

New Member
Dec 23, 2023
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United states
Well if they made them the same, for economy of scale, it would have to be for the 36v which would require higher ampacity wires. It would be interesting to calculate what the weight savings would be for the 48v motor.
Agreed, that is why i said they did not optimize for 48v, which would be lighter.
 

TCFlowClyde

Active member
Feb 26, 2022
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Mesa, AZ

calvintys

Active member
Sep 12, 2023
255
256
Malaysia
If where
Here it is peeps!😱 Finally, a $400 wireless remote dropper that plugs into the motor battery? It's OEM currently, but will be available next year for general retail.

How would this likely wire into our current CEF50 frame configuration?

It will be great if bafang integrate sram AXS or shimano automatic shifting into their system. I will definitely get it.
 

TCFlowClyde

Active member
Feb 26, 2022
1,347
870
Mesa, AZ
If where

It will be great if bafang integrate sram AXS or shimano automatic shifting into their system. I will definitely get it.
Nah, not me. I've seen both. They work as advertised. But riding techy uphill, I'd always want manual. I don't think most mtbers would find it useful enough to pay the extra costs and have that extra thing to troubleshoot it if/when it goes wrong.

However, this new wireless dropper is half the cost of AXS, runs off the motor which works well with the bigger 720Wh battery, and doesn't have the bulkier battery behind the saddle to tire rub! 3 positive things!

I assume there is a universal method to wire the plug in? Thoughts on the dropper...
 

calvintys

Active member
Sep 12, 2023
255
256
Malaysia
If
Nah, not me. I've seen both. They work as advertised. But riding techy uphill, I'd always want manual. I don't think most mtbers would find it useful enough to pay the extra costs and have that extra thing to troubleshoot it if/when it goes wrong.

However, this new wireless dropper is half the cost of AXS, runs off the motor which works well with the bigger 720Wh battery, and doesn't have the bulkier battery behind the saddle to tire rub! 3 positive things!

I assume there is a universal method to wire the plug in? Thoughts on the dropper...
If riding on our regular trail, regular shifting should be fine but i always encounter problem with new trail, especially during race, when i dont have enough practice run.
 

calvintys

Active member
Sep 12, 2023
255
256
Malaysia
I am still using OneUp dropper so i don't have much experience on electronics yet but if the new dropper its a carthage type. and the response its good why not give it a try as it will make my cockpit look clean.

As for AXS dropper, i worry my tire night hit the battery as my tire rubbing my waist water bag.
 

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