My Lightcarbon LCE930 build with Bafang M820

TobyB

New Member
Aug 26, 2023
27
37
Seattle WA
Regarding the alignment, when the bottom bolt is done:

On non drive side:
View attachment 122360

And on the drive side:

View attachment 122359

It is a little bit to one side, but probably less than half a mm from center. I think it is good.

Regarding the spacer length:
When I do tight only one top bolt (bottom also unbolted, to see the movement), this is the result:


The bolt is tight, but there is still a bit of play between the shock and the shock and the rocker arm. IMO, this indicates, that the spacers are a bit too narrow (considering I measured 45mm distance between the two) or (and?) bolts are a bit too long.

When you do both bolts, there is no play, because in a sense, shock is then suspended in the middle of the rocker arm, because rocker arm is very rigid.

As is, I don't think it is a big issue. Currently, I put few 10mm x 18mm x 0,1mm shims between the rocker arm and the shock, to take up the slack. I put more on the drive side, to help with the very slight misalignment, and shock is not pulled in the middle unnecessarily.
There is a company out of Italy (dhsign.it) doing some bushings that work like a spherical bearing, that might not be a bad idea if there is some alignment issues?
 

clix

Active member
Jul 24, 2022
185
206
EU
I recently put in an order for a frame and motor. Could i ask which cassette you put on here? And how does it pedal with no motor? I have a 2021 Norco range VLT with an Ep8000 and it is quite draggy. Also did it come with the bottom shock bolt? I have ordered the shock and hardware for the bushings but i'm not sure if i need the bolt and if so which size. Thanks
I have this cassette:

But if I would be buying it again, I would go for this one:

The one I have, LG400, is really heavy, 717g. Lg700 in the same range is 100g lighter.

IMO, the bike pedals well without the battery. If you remove the chain, and pedal by hand, you can feel some drag, but compared to the force produce by legs, needed to move the bike, it is relatively miniscule. While riding, additional weight is probably more noticeable than motor drag.

Regarding the battery, last week I recieved information from the seller, that it should be available at the beginning of the September. Fingers crossed!

The frame came with the shock bolt, yes.
 

clix

Active member
Jul 24, 2022
185
206
EU
There is a company out of Italy (dhsign.it) doing some bushings that work like a spherical bearing, that might not be a bad idea if there is some alignment issues?

IMO, this is mostly beneficial for standard mount shocks (non trunion). There might be a great solution, even without the misalignment, due to the frame flex and bending. The trunion mount is basically rigid, and even spherical movement in the lower mount wouldn't help that much.

Considering how small misalignment is, IMO I currently don't have a problem. But only time will tell, I guess. :)
 

clix

Active member
Jul 24, 2022
185
206
EU
Here is current build kit of the bike:

wheelsDT swiss E1900 29
tiresContinental Xynotal Trail and Xynotal Enduro
forkRockShox Lyrik select 2020
shockRockShox Super Deluxe Ultimate RC2T 2023 185x55
shock springRockShox 450lbs/inch
cassetteShimano LG400-11 11-50
derailleurShimano XT linglide RD M8130
shifterShimano XT linglide SL M8130
chainShimano linglide cn LG 500
dropper postOneUp components 210mm 31,6mm
dropper leverShimano SL MT500 ispec-ev
brakesShimano SLX M7120 4 pot
brake discsShimano RT66 220mm fron, 203m rear
stemNukeproof neutron AM 31.8mm, 35mm stem
barSpecialized 31.8 780mm riser bar
gripsESI extra chunky
saddleBrand-x cut out saddle
pedalsOneUp composite pedals

Fork will be changed between the two bikes, for 2023 Lyrik ultimate, once the battery arrives.
Last week I also received bushing calibration/burnishing tool and I burnished bushings of both forks. It does make a difference in the "car park test". Will see, how it will feel on the trail.

This is first coil shock for me. I chose this one, because it has hydraulic bottom out, additional damping during the last part of the travel, to prevent any harsh bottom outs, handy with coil shocks. Will see how it works.

Drivetrain is Shimano linkglide, to improve longevity. As I have already stated, I would go for Lg700 cassette now, instead of LG400.

For the brakes, I nearly went for Deore, but decided on SLX, to gain the knob for "tool free reach adjust".

Wheels should be budget, reliable, no frills option.

There is quite a bit of hype surrounding the new Conti tires, so I was keen to try them out.

Dropper is right now shorted to 190mm. Will see how it will work, and if maybe 200mm is possible.

Bar, stem and saddle I already had at home.
 

Goff

Member
Mar 2, 2023
76
83
New Zealand
Nice build! Hope you get a battery soon!

I am thinking about a custom battery, I know the bafang battery is 63x53x450mm and i can measure from drawing, but when you have the motor off, could you measure the actual space inside the downtube?
I am building my own battery too, that size is correct you won’t get anything bigger than that, it’s tight

3BC9ADB8-6D67-4298-99E7-05AC3F6CC57D.jpeg
 

clix

Active member
Jul 24, 2022
185
206
EU
Just received the same message 😄
But shés talking about the btf014 ans not the btf100, while we had a big discussion on the fact that I need the 36v and not 43v… I think I gonna have a surprise…
Huh, hope you recieve the correct one!
 

brbr

Active member
Dec 28, 2022
471
252
France
Huh, hope you recieve the correct one!
the messages were kind of crazy, she will finally send me the 43v, I think the package was already done, even though I asked for the 36v many times... well, I will change the firmware, not a big deal but the communication is annoying
 

clix

Active member
Jul 24, 2022
185
206
EU
That sux. Will they provide the besst tool, or give you discount or something?
 

clix

Active member
Jul 24, 2022
185
206
EU
I assembled the bike a few days ago and did the first shakedown run on the trails:

- through headset cable routing is really really annoying. I have 5 cables going through it, and it was a pain to squeeze the cables to the side and install the fork.
-there is not a lot of space for the cables just above the motor. I had to tape some to the side, so I was not pinching them too hard with the motor. I was still required to push the motor quite hard into the frame to squeeze the cables a bit. I use a full-length sleeve for the cables, to dampen the rattling noise. I am sure, that this didn't help in this case.
- I didn't want to use the spoke magnete, that came with the motor. I use the Sigma Sport one instead. I had to space out the sensor a bit(because the magnet is not that strong), so it looks quite janky, but I prefer this to the included magnet:
1695544730146.png


After all this, the bike works!

I set the speed limit with BESST tol to 32km/h for now.
Did the first run of 20km and 400m of elevation. On the flats I used eco, and on the hills, I mostly used sport (middle one).
I finished the ride with the indicated 69% battery left.

This is my first eMTB, so I can't compare it to other offerings on the market. But I can compare it to the TSDZ2 converted city/gravel bike that I use quite a lot.

Compared to the TSDZ2, the optimal cadence range is quite different. TSDZ2 feels like it has a lot of low-speed grunt, but at cca 80 crank RPM, it is completely out of puff. OSFW improves it quite a bit, but it is still not for higher cadences. It really is not for "sport riding" but for commuting, it is great.
M820 comparatively has lower torque at lower cadences, but I didn't manage to "spin it out", or find the high cadence limit. I believe this is much better, for actual mtb. The FW could be improved a bit, though. It feels like the torque sensor input has a bit of limited range, so you too quickly reach full power in a given mode. Will have to do more riding to confirm it.

Motor noise at lower cadences is not that loud, but at higher ones, it is quite pronounced. Even with the slim downtube, you are not fooling anyone, you are on the "normal bike" at this point. :D

Riding on the speed limit is implemented quite well. There is no jerkiness. The motor smoothly completes your power input, so the total required output power is just enough to ride at the limit.

On the downs, my motor has a loud and annoying rattle. When I was ordering, I was under the impression that these motors are quiet on the downs. I purposely went for DT350 hubs, with low POE number, because on the trail hubs are very quiet. But my motor isn't. :(

As for the whole bike, I didn't push it too hard, have to get used to to it. As far as the ride itself, I was quite surprised how a "few kg" from my normal MTB changed the ride. It is cca 5kg heavier. It feels much more planted and stable. Suspension is performing a bit better(less feedback to hands and feet), due to the higher sprung weight. Direction changes require a bit more effort. And bunny hopping is quite a bit harder. Will have to get used to this, and to some purposeful training. :)

Will report back, after a few more rides.
 

Zimmerframe

MUPPET
Subscriber
Jun 12, 2019
13,907
20,614
Brittany, France
On the downs, my motor has a loud and annoying rattle.

This is like the EP8 or Bosch Gen4. Not sure why, but I didn't expect the Bafang to be the same, but then if that mechanism is the most efficient way to do things, maybe I should have expected it. I Have the M510, but they presumably have used a similar system in the M820 ?

It's pretty easy to replicate if it's the same :


I'm not sure why, but at 400km's mine doesn't seem to do it as much. I'm not sure if something has bedded in (the whole motor is considerably quieter than it was when new) or if I'm just going faster with it and don't notice because of wind/trail noise. I actually stopped the other day and did the chain test just to make sure it still rattled - it did !
 

clix

Active member
Jul 24, 2022
185
206
EU
Another ride today.
28km and 750m of elevation. I started with 100% and at the end it was at 40% battery. 95% of the climbing was in "sport" mode, middle one. On the flats it was eco.

Still rattles, and still whiney on the ups. but it looks like I am geting used to it. :D
I have some problems with the headset, that came with the bike. Even tough it is properly set up, it is a creaky mofo..
I don't know it is related to actual headset of to the inmolded headset bearing cups in the frame.

I ordered another one, to see if it will improve:

Otherwise, bike rides great! :)
 

JimLee-Lightcarbon

Lightcarbon
Apr 15, 2022
277
317
Amoy
I assembled the bike a few days ago and did the first shakedown run on the trails:

- through headset cable routing is really really annoying. I have 5 cables going through it, and it was a pain to squeeze the cables to the side and install the fork.
-there is not a lot of space for the cables just above the motor. I had to tape some to the side, so I was not pinching them too hard with the motor. I was still required to push the motor quite hard into the frame to squeeze the cables a bit. I use a full-length sleeve for the cables, to dampen the rattling noise. I am sure, that this didn't help in this case.
- I didn't want to use the spoke magnete, that came with the motor. I use the Sigma Sport one instead. I had to space out the sensor a bit(because the magnet is not that strong), so it looks quite janky, but I prefer this to the included magnet:
View attachment 125407

After all this, the bike works!

I set the speed limit with BESST tol to 32km/h for now.
Did the first run of 20km and 400m of elevation. On the flats I used eco, and on the hills, I mostly used sport (middle one).
I finished the ride with the indicated 69% battery left.

This is my first eMTB, so I can't compare it to other offerings on the market. But I can compare it to the TSDZ2 converted city/gravel bike that I use quite a lot.

Compared to the TSDZ2, the optimal cadence range is quite different. TSDZ2 feels like it has a lot of low-speed grunt, but at cca 80 crank RPM, it is completely out of puff. OSFW improves it quite a bit, but it is still not for higher cadences. It really is not for "sport riding" but for commuting, it is great.
M820 comparatively has lower torque at lower cadences, but I didn't manage to "spin it out", or find the high cadence limit. I believe this is much better, for actual mtb. The FW could be improved a bit, though. It feels like the torque sensor input has a bit of limited range, so you too quickly reach full power in a given mode. Will have to do more riding to confirm it.

Motor noise at lower cadences is not that loud, but at higher ones, it is quite pronounced. Even with the slim downtube, you are not fooling anyone, you are on the "normal bike" at this point. :D

Riding on the speed limit is implemented quite well. There is no jerkiness. The motor smoothly completes your power input, so the total required output power is just enough to ride at the limit.

On the downs, my motor has a loud and annoying rattle. When I was ordering, I was under the impression that these motors are quiet on the downs. I purposely went for DT350 hubs, with low POE number, because on the trail hubs are very quiet. But my motor isn't. :(

As for the whole bike, I didn't push it too hard, have to get used to to it. As far as the ride itself, I was quite surprised how a "few kg" from my normal MTB changed the ride. It is cca 5kg heavier. It feels much more planted and stable. Suspension is performing a bit better(less feedback to hands and feet), due to the higher sprung weight. Direction changes require a bit more effort. And bunny hopping is quite a bit harder. Will have to get used to this, and to some purposeful training. :)

Will report back, after a few more rides.
About the M820 motor system, I contact with bafang company and they said if anyone who can post a video and tal about the problem the M820 motor ,so they will try to solve based on the problem, just like the noise, or othe problem,
 

brbr

Active member
Dec 28, 2022
471
252
France
About the M820 motor system, I contact with bafang company and they said if anyone who can post a video and tal about the problem the M820 motor ,so they will try to solve based on the problem, just like the noise, or othe problem,
I guess @Rob Rides EMTB will do it soon!
On my side, heating issues when climbing long time in boost mode, noise when climbing, and also the ball bearing or marbles noise when assistance engages or disengages
 

clix

Active member
Jul 24, 2022
185
206
EU
Another ride today.
28km and 750m of elevation. I started with 100% and at the end it was at 40% battery. 95% of the climbing was in "sport" mode, middle one. On the flats it was eco.

Still rattles, and still whiney on the ups. but it looks like I am geting used to it. :D
I have some problems with the headset, that came with the bike. Even tough it is properly set up, it is a creaky mofo..
I don't know it is related to actual headset of to the inmolded headset bearing cups in the frame.

I ordered another one, to see if it will improve:

Otherwise, bike rides great! :)
I decided to empty the battery, that was left from yesterday. I used same modes, eco on flats and sport on the climbs.

It actually went quite quickly from 40% to 20%. I did aproximatly another 250m with "sport" mode. After that, I was limited to only cca 110-120W, of electric input power. Til 12% it went quite quickly, but aftar that, it was for a long time on 12% and 11%. While I was stationary, It sudenly jumped to 6% and than went quite linearly down to 0%. In the end, on this round I did 26km and 550m of vertical assend.

Together with previous day, 410Wh battery allowed me to do 54km and exactly 1300m of vertical elevation. But the last 300m (from 20% to 0%) were verry limited with power. Still easier than "unpluged bike" only.

So, overall, it looks like for my weigth (72kg out of shower), my riding style (climbing in sport mode, flats in eco at 32kmh) and my terain I am good for 1000m of vertical and than, cca 200m with very reduced power, if I want, and still have enoguh to come back home.
 

JimLee-Lightcarbon

Lightcarbon
Apr 15, 2022
277
317
Amoy
I decided to empty the battery, that was left from yesterday. I used same modes, eco on flats and sport on the climbs.

It actually went quite quickly from 40% to 20%. I did aproximatly another 250m with "sport" mode. After that, I was limited to only cca 110-120W, of electric input power. Til 12% it went quite quickly, but aftar that, it was for a long time on 12% and 11%. While I was stationary, It sudenly jumped to 6% and than went quite linearly down to 0%. In the end, on this round I did 26km and 550m of vertical assend.

Together with previous day, 410Wh battery allowed me to do 54km and exactly 1300m of vertical elevation. But the last 300m (from 20% to 0%) were verry limited with power. Still easier than "unpluged bike" only.

So, overall, it looks like for my weigth (72kg out of shower), my riding style (climbing in sport mode, flats in eco at 32kmh) and my terain I am good for 1000m of vertical and than, cca 200m with very reduced power, if I want, and still have enoguh to come back home.
About the head set, is there any suggestions or feedback about it?Except it's too crowded to pass five cables, Maybe it would be better to use external routing instead?
 

clix

Active member
Jul 24, 2022
185
206
EU
I did another ride today. 920m of elevation and 32km. When I came home, battery, was preaty much finished, 12%. For the climbing, this time I was in the S+ mode, 4/5. But this time, I was not pushing myself up the climbs, I was not givng a lot of effort. But the motor power was preaty much the same, regardles of my input power. I think this is quite a drawback of this motor. It gives all its power even if you are just spining your pedaly without much efort. Because of this, it doesn't incentivise you to push harder. Whitch in turn draints the small bateries even quicker. Hope there will be improved FW in the future.
 

brbr

Active member
Dec 28, 2022
471
252
France
I did another ride today. 920m of elevation and 32km. When I came home, battery, was preaty much finished, 12%. For the climbing, this time I was in the S+ mode, 4/5. But this time, I was not pushing myself up the climbs, I was not givng a lot of effort. But the motor power was preaty much the same, regardles of my input power. I think this is quite a drawback of this motor. It gives all its power even if you are just spining your pedaly without much efort. Because of this, it doesn't incentivise you to push harder. Whitch in turn draints the small bateries even quicker. Hope there will be improved FW in the future.
Yeah we need an adaptive mode such as the emtb on Bosch
 

clix

Active member
Jul 24, 2022
185
206
EU
Yeah we need an adaptive mode such as the emtb on Bosch
Yea, that would be the best. But even without it, I believe it could still be much better :)
For anyone reading, that has not tried it yet: It is not unridable or anything like that. It is still very fun. But it could be even better. :D :D :D
 

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