M820 or M510 ?

[souftosouf]

Hello everyone,

I previously owned a Bulls EVO AM1 Bosch Performance CX (GEN 4) with a 650Wh battery, 140mm travel, 203mm discs, and Sram GX Eagle transmission. It was perfect. It got stolen. Since then, I've been using a TSDZ2B for commuting and sometimes just cruising around. It has 85Nm of torque but isn't as powerful as the Bulls.

I want to build a bike, but I can't decide between the M510 and M820.

Pros of M820:

• Lightweight in general, with good-looking frames available (CEF50)
• Newer

Pros of M510:

• More torque and power (711W peak power)
• Standard batteries and removable battery on many frames (DENGFU E82)

I'm seeking advice from people who have owned both a Bafang and a Bosch motor. My questions are as follows:

1. I was in eco mode 95% of the time with the Bosch. But I loved the fact that tour and turbo modes were available if I needed to rush somewhere. Is the M820 much less powerful than the Bosch on max assist? Does it require a lot of input to get the max power?
2. Is the M510 a good motor relative to the Bosch? Does it still have the issues it had at it beginning?
3. What is the feeling with Bafang motors? Does it feel natural when pedaling?

My TSDZ2B is quite good, but I'm looking for much more power on max assist.
I dont know if i care that much about weight, 2kg more is that bad if i get a lot of power

Thanks for your advice.

 

[lkdoido]

Hi, I'm about to enter the world of EMTB, but my wife has a Shimano E7000 with a 504W battery. I believe that the m820 is for enthusiasts who like to have control of the rhythm and will only use ECO, while the m510 is for those who want to enjoy TRAIL without worrying, the removable battery is a very interesting plus. I'm riding the m820 because I lose to the boss on the climbs, but flat, descent or technical sections still dictate the pace. Here in Brazil it is difficult to access most ebikes, some local alternatives and large specialized and trek brands.

 

[Bengy22]

My TSDZ2B is quite good, but I'm looking for much more power on max assist.
I don't know if I care that much about weight, 2kg more is that bad if I get a lot of power

I'm not able to answer most of your questions as I've never ridden both motors but from what I've read / watched online the Gen 4 CX is a beast of a motor if you are expecting the m820 or the m510 to blow it out of the water power wise (as you can tell with your TSDZ2B experience torque figures are not everything) I would say you are going to be disappointed. The m820 is a lightweight motor that doesn't have the power to compete in the full power class. The m510 seems to be close though, I've seen some still claim the CX still felt more powerful but overall very close. I believe Rob and Neeko Devinchi have videos discussing these two motors. If you want a jump in power you might need to go M560

 

[Chris999]

I've recently purchased a M510 Bafang based bike after having a Gen 2 65Nm Bosch for 8 years. Both hardtail bikes and like you I ride predominantly in ECO on the Bosch. I drank the Kool aid when buying the Bafang as it seemed very powerful but after a number of rides decided it was way over the top and I wanted to dial it down. The default m510 has 140% assist on level 1, similar to Tour mode on Bosch. There is no Eco mode on the default tuning. Ended up buying a Bafang Besst tuning kit and set the levels down. Level 1 is now 60% assist with max of 25% motor power (default 50%) and acceleration of 2 (default 4). It is like a different bike to ride. Hence if you go with the Bafang I would factor in the price of a tuning kit.

 

[souftosouf]

Thanks everyone for your replies. I wanted to correct some things that I haven't made clear yet:

My TSDZ2B is really good; I can climb 3% hills at 25kph with almost no effort. If the M820 is as good, I'm fine with that. Buying the best tool is part of the plan. I want a Bafang so I can configure it myself.

So far, the information that I understand:

1. M510 is too powerful out of the box.
2. M820 can't compete with CX Gen 4.

And the question that I have now:

1. What's the purpose of the M820 when the M510 is more powerful for just 0.600g more?
2. Is the M510 reliable?

 

[patdam]

My opinion. After several month of ride with the M820, i have taken the M510 for a week of ride in spain. Finally I love the 2 bike/motor, the only criter of choice will be the guys who will ride with me. if they are assisted, the M510. Unassisted the M820. And when i'm alone, depending the track or my spirit. The M510 is more enduro with 160/170 travel, the M820 more "trail" with 150 travel. For speedy flow tracks, the M510. For slow technical, the M820. The M820 can't climb as slope so step that the M510 as able. The M510 as more hard to drive in down single, slow and hard technicaly. It's also take a little more space when braking. About capacity of the M510 regarding the other major brand motors, nothing less (may be few more ?). With my 100 kg i can follow my friends with a yamaha and shimano sin any problems. A few more consumtion, compasate by larger battery (17Ah/48V in regard of 17Ah/36V). It provide exactely the same result on the batery decreas.

 

[patdam]

About of the interest of M820 regarding M510. It's not only 0.600 gr less, but mostly 2kg. The battery needed to do +- the same thing is also more light (+- 1.5 kg).

 

[Adam Anderson]

CEF50 starts from 17.75KG according to the suppliers. They have the battery option 43v 11.4ah at 2.6kg. It's a great choice to get a super lightweight emtb.

 

[borysgo2]

I can add my 2 cents to the conversation. I have M820 motor equipped bike.
In terms of power, please BOYS and GIRLS, power is not the torque, unit of the power is Watt, the fact that motor have less torque does not mean that have less power. M820 at 43V firmware throws about 580W of power which is a lot. CX4 motor puts maybe about 100W more.

Question is how much of a time You are going to spend on max assistent mode ? If this is the main factor, than bigger, more powerful motor motor would be better.

In my case I am using only first 3 assistent modes from all 5 (M820), so the weight saved on motor can be spend on the bigger battery.

I am riding with the boys with CX4 and EP801 motors and do not feel any need of more powerful motor.

 

[patdam]

I can add my 2 cents to the conversation. I have M820 motor equipped bike.
In terms of power, please BOYS and GIRLS, power is not the torque, unit of the power is Watt, the fact that motor have less torque does not mean that have less power. M820 at 43V firmware throws about 580W of power which is a lot. CX4 motor puts maybe about 100W more.

Question is how much of a time You are going to spend on max assistent mode ? If this is the main factor, than bigger, more powerful motor motor would be better.

In my case I am using only first 3 assistent modes from all 5 (M820), so the weight saved on motor can be spend on the bigger battery.

I am riding with the boys with CX4 and EP801 motors and do not feel any need of more powerful motor.

how many wheight are you ? on which tracks do you ride (km + D+) ? In regard of my charasteristics: 100 kg wheight and moutain ride (30km 1500 d+), i'm disagre with you, i can't follow full motors with the M820. i can't climb 20% during long time, that i can do with the M510.

 

[borysgo2]

how many wheight are you ? on which tracks do you ride (km + D+) ? In regard of my charasteristics: 100 kg wheight and moutain ride (30km 1500 d+), i'm disagre with you, i can't follow full motors with the M820. i can't climb 20% during long time, that i can do with the M510.

I weight about 95kG in the pants so close to 100kG geared up.
Yesterday I have done 40km@1100m about 55% battery used (DIY battery).

''i can't climb 20% during long time, that i can do with the M510''

Please elaborate a bit if possible, is it M820 throttling and loosing power after a long climb ?
In your opinion is the m510 more battery friendly ?

Thanks.

 

[patdam]

"Please elaborate a bit if possible, is it M820 throttling and loosing power after a long climb ?"

In fact as i have quickly power variations in boost (cause too hot following bafang ?), i have adjust my level assist to 20%, 40%, 80%, 90%, 100% and as the differency between S (80%) ans S+ (90%) is very low, i mostly use S to climb hard, never boost. but M510 can provide clearly more power on high level with less torque on cranks, i could said +- 1/3 more. that allow i can climb that i can't with the M820


"In your opinion is the m510 more battery friendly ?" i don't understand that you would mean by "friendly" ? that i can said is that for same use (M820 in S 80% and M510 in T 50%), the M820 consume a lot off less. in the same travel, where i consume 50% with the M510, i consume 30% with the M820 (aproximatively)

Clearly, i can repeat several days in the row the track that your show with the M510. not with the M820, i can do that 1 time, but i need to recuperate physically in following

It's my feeling and i know, it's ofen different than other users.

 

[souftosouf]

Thanks everyone for your replies !

i think i need to try a lightweight motor to make my final decision.
I like the M510 but it seems to have a lot of problems, and i cant find a fork that allow tapered 170mm fork
CEF 50 seems to be the best frame so far

 

[Neeko DeVinchi]

Personally, I am leaning more towards the M820 system nowadays.
But I still enjoy the power and feel of the M510 when riding with other full-fat emtbs. Especially if everyone rider just sticks the bike into turbo/boost mode

Ultimately, the system is only as good as the implementation and the frame' geometry.
The above being 2 good examples.

With more options to look forward too

 

[LAnton]

Personally, I am leaning more towards the M820 system nowadays.
But I still enjoy the power and feel of the M510 when riding with other full-fat emtbs. Especially if everyone rider just sticks the bike into turbo/boost mode
View attachment 140349
Ultimately, the system is only as good as the implementation and the frame' geometry.
The above being 2 good examples.
View attachment 140353
With more options to look forward too
View attachment 140354

It doesn't seem strange to you. Earlier, dengfu wrote that the stroke of the rear suspension is 170mm. And now he writes 160mm and 150mm.

 

[Neeko DeVinchi]

It doesn't seem strange to you. Earlier, dengfu wrote that the stroke of the rear suspension is 170mm. And now he writes 160mm and 150mm.

I reserve judgement until I've built up both and have my suspension chap determine the rear wheel axle path and measure the vertical rear wheel travel

 

[souftosouf]

Thanks everyone for your reply, i think i'll get a M820 since i almost never used neither turbo with my previous bike.
I'll compensate the 75NM by getting a biger crank length if needed.
I'll update this thread once i finish my bike.

 

[lkdoido]

HI, I made the same considerations and here in Brazil, in the region where I travel, there are few climbs over 100m and a 20% gradient, today I already do these XC sections without a motor, so a little help is enough. As I'm not a jumper I'll keep the 170mm crank. Big hug and happiness in your choice.