M820 Bafang - CEF50 frame (lightweight)

TCFlowClyde

Active member
Feb 26, 2022
851
492
Mesa, AZ
See the M820 motor discussion for preliminary details...just making a specific CEF50 frame owners topic.

Total cost with shipping for me was $1750 US. Production starts this February. So, I put down a $500 deposit for a L-size hoping I don't get burned. πŸ’ΈπŸ˜πŸ»

Screenshot_20221215-142403.png Screenshot_20221228-235225.png Screenshot_20221215-215348.png Screenshot_20221216-084950.png Screenshot_20221216-085220.png
 
Last edited:

TCFlowClyde

Active member
Feb 26, 2022
851
492
Mesa, AZ
Here's the 720Wh in-house, bigger battery option. The smaller is the 410 Wh Bafang battery. Both are integrated (motor dismount required) in order to save weight on the frame cutout, cradle hardware, and key latch system. Purportedly, this strategy can save 2-3 lbs off the total build. We'll see! πŸ’ͺ🀞

No range extender is planned. So, I opted for the bigger one knowing the 75Nm/95Nm peak motor power will inherently consume more battery range. Plus, I'm a heavy Clyde-rider.

Screenshot_20221229-232156.png
 

TCFlowClyde

Active member
Feb 26, 2022
851
492
Mesa, AZ
What does CEF50 stand for?
C = carbon
E = electric PAS.
F = Freeride?
50 = under 50 lbs?😁

Or it's just probably a random engineering tag?🍻
 

TCFlowClyde

Active member
Feb 26, 2022
851
492
Mesa, AZ
So, simply why not await the stealthier, swappable 430 Wh battery of the Transition Relay? (Which I've been drooling over since I the rode the lesser powered/suspension travel of Trek Fuel Ex-e and ironically timed, Transition Relay public announcement!)

πŸ’ΈπŸ’ΈπŸ’ΈπŸ’Έ Is the answer. Especially, since, I found out that the Relay will likely not offer a frameset option (spoke to Transition last week) as lowest price point...I kinda killed it as the go-to-rig-in-waiting! They teased at the frameset option, but that seemed to be disconfirmed as time passed.

Logic: What I lose, in stealth and convenience of the trail-side swappable spare battery (Fazua is late with their 250 Wh range extender according to Pivot in last week's conversation) I'll gain in M820 beefier 75Nm/95Nm peak torque with the heavier 720 Wh battery.

Overall, I'm shooting for 42/43 lbs full wet-weight: pedals, higher end spec with thicker, heavier carcass, 27.5er plus 3.0" incl. sealant/foam inserts, and lastly a slighter heavier 180 Zeb Ultimate fork/ 160 ish RS ultimate coil rear shock.

Note. I rode a friend's Fuel Ex-e and luv'd the lightness and agility, and impressive low silhouette leading to the uncanny stealthness. He should be able to ride all mtb singletrack in North America relatively worry-free. I also luv the TQ50 small design, but it should be enhanced to the future TQ65 with the short super-turbo burst mode for my needs. And I need the Enduro suspension 170+f/150+t travel, with an easily removable battery...like the Transition Relay Fazua60, in order to pack a spare as I'm a heavier rider.

But alas, The Relay dream is not likely for this year's budget...maybe next year's. Plus, I really didn't want to sell a kidney to help finance it.😁 Consequently, I'm giving the M820 CEF50 a try with less economic risk. 🀞🀞🀞

It'll be interesting to see who else is willing to Beta-test their CEF50 rendering for the Bafanger community at large!πŸ’ͺ

Here's to a higher mid-powered, semi-stealthy, 42/43 lb build. Bravely done if you buy one too!🍻
 
Last edited:

thaeber

Well-known member
Jan 26, 2021
830
728
Bruchsal, Germany
Great plan, and I think You will not be disappointed. May be You can overstroke (210x55 / 216 x 63 shock?) the frame a litte to get more travel and better matching Your 180mm ZEB.
Would be very interesting to know if the battery supports CAN communication with the motor controller and display. If not, it would be easy to add a DIY battery pack as range extender by using a split / parallel connector. Cant wait to see first pictures!
 

TCFlowClyde

Active member
Feb 26, 2022
851
492
Mesa, AZ
Great plan, and I think You will not be disappointed. May be You can overstroke (210x55 / 216 x 63 shock?) the frame a litte to get more travel and better matching Your 180mm ZEB.
Would be very interesting to know if the battery supports CAN communication with the motor controller and display. If not, it would be easy to add a DIY battery pack as range extender by using a split / parallel connector. Cant wait to see first pictures!
Yeah, I thought about the 216x63.5 RS coil, but I went with 210x55 to "overstroke" the rear within the manufacturer's eye-to-eye spec...I was afraid to truly size up for fear of the full carbon swingarm and my heavier weight. The kinematics may get me closer to 160mm. It should be more than 155 mm and much more than the 150 mm spec.🀞

Plus, the RS 210 x 55 coil was on sale for $300 USD....$200 off my limited, overall suspension budget for the '22 model...so bonus savings!πŸ˜„πŸ’Έ

I also wanted the newer RS coil upgrades, especially the purple button bottom-out adjustor. But I'm playing it safe. However, if others go for the bigger coil successfully, I'd definitely spend the extra money on those upgrades and bigger stroke later on!πŸ€™

Screenshot_20230102-163537.png
 
Last edited:

thaeber

Well-known member
Jan 26, 2021
830
728
Bruchsal, Germany
Yeah, I thought about the 216x63.5 RS coil, but I went with 210x55 to "overstroke" the rear within the manufacturer's eye-to-eye spec...I
Be careful, the additional 5mm stroke will give You 10-15 mm more travel depending on end of stroke ratio / progression. Good that there is no bridge between the seatstays, but worst case the tire may hit the seattube. Did You consider a mullet setup with 27.5 rear wheel to be on the safe side?
 

TCFlowClyde

Active member
Feb 26, 2022
851
492
Mesa, AZ
Be careful, the additional 5mm stroke will give You 10-15 mm more travel depending on end of stroke ratio / progression. Good that there is no bridge between the seatstays, but worst case the tire may hit the seattube. Did You consider a mullet setup with 27.5 rear wheel to be on the safe side?
Exactly, I was hoping the leverage curve might be similar to my LCES04, I think 2:1 ratio. So, I guesstimate 7-10 mm increase, 10-15 would be nicer! 🀞

It looks like this linkage will allow the back tire clear the seat tube with room to spare. Also, the other issue were seat stays becoming more vulnerable to breaking if I attempted to overstroke out of eye-to-eye spec at 210 mm to 216 mm due to creating a higher pivot point, especially carbon, with heavier riders.🀞

But, I'll ask the salesperson soon to see if their engineers will produce a chart for public consumption to better predict travel and see how progressive the frame kinematics can be.

On mixed wheelsize: I myself prefer the mullet with a longer chainstay.(450 mm). But I decided to keep with my 27.5er+ carbon wheelset to save on the cost on the front 29er. So cost limitations.

Also, I bought the 180mm (v. 170mm spec) 27.5er fork because I knew it would give a higher BB height to compensate for the slight lower 27.5 plus tire height at 28.75". Rake was still 44.4 deg offset for longer travel. Bonus, was the new 3.0 charger damper and buttercup rebound adjustments found in the Zeb Ultimate going forward. And the cost reduction was nice at $700 USD instead of $1150 for '22 model.

Together the Zeb '22 with RS ultimate coil '22, I was able to spend $1000 USD! πŸ’ΈπŸ’ͺ So, finances guided my travel and wheelsizing.πŸ˜πŸ’°
 
Last edited:

thaeber

Well-known member
Jan 26, 2021
830
728
Bruchsal, Germany
Sounds like a plan mate! I missed the info that You plan to run both wheels 27.5 somehow, but I think with the frame designed for 29 rear wheel there will be no issues with 27.5 and increased 55 stroke.
 

TCFlowClyde

Active member
Feb 26, 2022
851
492
Mesa, AZ
Sounds like a plan mate! I missed the info that You plan to run both wheels 27.5 somehow, but I think with the frame designed for 29 rear wheel there will be no issues with 27.5 and increased 55 stroke.
πŸ’― Esp. the taller 27.5 plus are 28.74", so close to standard 29" wheels on bigger 180 mm fork should yield similar angle to the front end to the spec 29/170 mm fork. Get a little more plushness on the front end with 10 mm.😁
 

LAnton

Active member
May 12, 2022
417
347
Russia
We will test together. But I want to make the lightest electric bike possible. 140mm front Pike and 140 rear sid. Since I have a set of 27.5 and 29 carbon wheels, I will choose the best option. I will also receive a frame no earlier than the end of February. I hope to get the M820 motor in the near future.
 

LAnton

Active member
May 12, 2022
417
347
Russia
It's a bad idea to make a non-removable battery. Then you will add a range Extender that weighs another 2000 g. It is better to install a removable battery bottle and you will have two spare batteries. Aliexpress has a very large selection of battery bottles.
 

TCFlowClyde

Active member
Feb 26, 2022
851
492
Mesa, AZ
Would be very interesting to know if the battery supports CAN communication with the motor controller and display. If not, it would be easy to add a DIY battery pack as range extender by using a split / parallel connector. Cant wait to see first pictures!
πŸ’― So, can likely splice this Amazon 380Wh extender in fairly easily?πŸ‘
 

thaeber

Well-known member
Jan 26, 2021
830
728
Bruchsal, Germany
Yes, but You need to be careful. You need an Y-split cable in parallel configuration. You need to install / connect the extender battery when both (frame and extender) battery are fully charged. Otherwise there will be a high current flowing from the higher voltage battery to the lower one, that may destroy something.
 

TCFlowClyde

Active member
Feb 26, 2022
851
492
Mesa, AZ
Yes, but You need to be careful. You need an Y-split cable in parallel configuration. You need to install / connect the extender battery when both (frame and extender) battery are fully charged. Otherwise there will be a high current flowing from the higher voltage battery to the lower one, that may destroy something.
Ok cool.πŸ’ͺ

I'll plan on pursuing this option after I get the build setup in a few months.🀞
 

EMTB Forums

Since 2018

The World's largest electric mountain bike community.

488K
Messages
23,630
Members
Join Our Community

Latest articles


Top