Dji avinox- Amflow

Lexle

Member
Jun 4, 2023
71
67
Germany
Amflow first needs to prove itself IRL usage in all conditions. As It's a trail bike I am pretty sure people will want to overfork it to 170+ mm with a beafier 38mm fork, as a 36 is a bit lackluster on an emtb unless you buy it for cross country. A bigger fork will cause the back end with the tiny shock to suffer. A beafier suspension needs stronger brakes, there is the possible issue with the rear sensor disc not allowing a thicker brake rotor to be mounted due to clearance issues. The biggest hurdle and a tough one will be providing local support/service for the users. I know I definitely don't want to call an online support service or drive/ship the bike 300km+ to the first offical dealer/service.

Owning an emtb only two seasons, some electrical/electronic issues, a warranty motor replacement, the extra hassle of changing the brake lines, dropper lines, etc(all go under the motor with the majority of bikes), I came to a conclusion that, no matter the revolution, Power or Nm numbers I would never buy an emtb online or from a brand that doesn't have a reputable local dealer/service with a partnership of the chosen brand emtb.
An online chat line(most likely AI based on the start level, like a lot of brands choose to do) saying stuff like " turn of the bike for 10s and then back on" doesn't help when you start having water ingress or other electronically related issues on an ebike.

Owning a machine(what an mtb with a motor actually is) without local support and service is a Big NO GO.
-----------------------------

Also a bit about electric motor power and the 250W nominal power limit in the EU, as I see there seem to be some misconceptions about how an electric DC motor works and how the 250W limit is imposed on manufacturers.》》》》

The power output of an electric motor is a complex measurment:

P(Watt) = V(Volt) * I(Ampere)is only true in special circumstances eg when the load is a resistor.
It is not true in cases of an electric motor, whose real output depends on its Q factor, switching control, load etc.
This is because a motor gets pushed around its axle by solenoids, whose voltage across their terminals varies with time, the intensity of the current flowing through it is also a function of time, the output power is also a function of time with more variables than just V (voltage) and I (current Intensity).
Each function has also its harmonics, the resultant P is a complex function and it can be only measured in a lab environment.
The power is usually measured while the motor reaches its thermal equilibrium in a room at 25°C. Then there's also the factor of internal transmission that needs to be taken into consideration when looking at the final crank output numbers, if you look at some test diagrams from a german test lab the real crank Nm outputs are far lower than the speced motor are...


Also as I see a lot of people are confused about the 250W Power limit in EU, I did a little bit of online research about the European legislation EN15194, it is the standard that is most commonly applied, so maybe the bottom description will clears things up why such differences between brands.>>>>

There's effectively no limit in the European legislation EN15194, which It's all about the words and test methods, neither of which pin it down. The rules are that the manufacturer must not label the motor with more than 250w and a motor with a 250w label mustn't overheat when running at 250w continuous. You have to be careful about terminology and calculations. If you have a 20 amp controller and a battery at 40V, you can take as much as 800W from the battery, but at the low speeds where the controller will allow that current, efficiency will be as low as 25%, so the output power will only be 200W. When the motor is spinning fast enough to reach its 80% efficiency, the back EMF from the motor cuts down the current, so the maximum current from the battery might only be 10 amps max, so output power will be 10 amps x 40v x 0.8 efficiency = 320w.


From the attached diagram it can be concluded that the maximal torque of the motor is at very low speed. This is advantageous because it gives very good starting behaviour, but also means
high values of the current and the efficiency is small. So we have to deal with heating problems. The power reaches its maximum at the midle value of the speed, but here the efficiency of the motor is still very small and the problem of heating still persists. The highest value of the efficiency is at 4000 RPM close to the maximum value of the speed. This could be a good operating point, but here both the torque and the power of the motor are rather small. There are also some mechanical constrains to be taken into consideration. The shaft speed of the DC motor is 4000 RPM. This corresponds about an 80 km/h speed of the vehicle if the shaft of the DC motor is connected directly to the shaft of wheel. At a such kind of speed the power need to drive the vehicle would be much higher than that DC motor could deliver, that's where the internal motor transmission comes into play.

View attachment 148187
Regarding the Discs I will let you know when I Change them to Swissstopp Rotors, I‚m pretty sure It will fit. Regarding service, I have a lot of Dealers for Amflow within 10-15 Km around my home and I buy it at a dealer. So if there will be a problem it will be his Job to fix it :) and yes the Amflow is a Trail bike exactly like a Levo
 

Lexle

Member
Jun 4, 2023
71
67
Germany
I didn't expect most people to understand, but it was a try to give at least some insight...as written it's not as simple as a number on paper, really. Good points, would probably be the only real measurement that would bring all vehicles to the same final level, but that will probably never happen.

Just out ofcuriosity as these things interest me, I am still waiting to see what a real lab test of the Avinox will show...the mass of the motor is small, so thermal stability is a question here...

Everyone thinks the new Bosch BDU38 is a miss, I don't think so, I think this motor is just a base for the next step.

The most interesting improvement i think is that the Bosch gen5 has a significant improvement in the thermal stability area, it's thermal stability was high before but now it's really high and longer lasting as can be seen in this diagram.

View attachment 148220
Derating starts massive after 13 Minutes, this is no real benchmark , how many steep HM can you go in 13 Minutes?. The test ist done with an uncovered Motor with a big fan below. Something that is not happening in reality (Velomotion is only doing that, to have a neutral view for comparison, not being affected by different frames or covers)

Gen 5 falls down below brose after 13:30 minutes rapidly and is below Pinion.. so don‘t know where you base on the „thermal stability“ of Gen 5
IMG_1517.jpeg
 

Lexle

Member
Jun 4, 2023
71
67
Germany
Two test benches, nearly same results input 250 watts.. So Bosch above 600 watts peak seams to be a fairytale


IMG_1515.jpeg
IMG_1514.jpeg
 

Bengy22

Member
Aug 25, 2022
125
80
USA
Two test benches, nearly same results input 250 watts.. So Bosch above 600 watts peak seams to be a fairytale
Does seem to depend on the publication though, as Ebike-mtb's testing shows a different result. Unfortunately I don't speak German so it's not easily for me to follow exactly how they do their testing, so maybe the testing method is different, giving different results. I do see in the comments though they are planning on testing the DJI soon, so it will be good to directly compare results to the Bosch along with the thermal tests they do.
1729438881216.png
 

Rob Rides EMTB

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Jan 14, 2018
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Surrey, UK
Does seem to depend on the publication though, as Ebike-mtb's testing shows a different result. Unfortunately I don't speak German so it's not easily for me to follow exactly how they do their testing, so maybe the testing method is different, giving different results. I do see in the comments though they are planning on testing the DJI soon, so it will be good to directly compare results to the Bosch along with the thermal tests they do. View attachment 148546

Is it that one is measuring Electrical output and the other is measuring mechanical output at the rear wheel?
 

Shark58

Active member
Mar 5, 2023
231
167
Germany
Is it that one is measuring Electrical output and the other is measuring mechanical output at the rear wheel?
To my understanding ebike-mtb is measuring electrical output and the others mechanical output at the chainring.

In their technical data Bosch states 600 W max motor power for the CX motors measured at the chainring.
 

emtbeast

Active member
Jan 10, 2022
282
326
Slovenia
Two test benches, nearly same results input 250 watts.. So Bosch above 600 watts peak seams to be a fairytale


View attachment 148533 View attachment 148534
Yep u are right they are different, are u surprised, well I am not.

Do you know each test bench standards(cadence, test duration, input power, tires, bike gearing, point of measuring(wheel or crank), is it electrical or mechanical power, weight, room temperature, etc..., most probably they aren't the same...

Yep the Brose almost doesn't derate, why don't you tell the reason also (it's in the video) let me say, because it has set an extremely high temp limit(can confirm myself) riding along my budy his levo motor heats up all the way to 89°C(we checked in app after a 1000m average 9% climb)...you could fry an egg on his motor.

Look, thanks but I don't need any info about the bike, I am not interested as there are no dealers no where near me, and even if there were,...

The trail geo just isn't my thing(it reminds me on the yt jeffsy), kinked seat tube is a no go, a phone display on an ebike, no thank you, if I ride I ride, I don't need a gazillion information when riding a bicycle and several remotes, all this and apps etc... it's just extra distraction and stuff that can break.

IMO an emtb only needs:

An ergonomic(towards the fingers tilted) simple small remote with haptic and/or audio feedback that has buttons for assistance levels and a on/off button, just dead simple and user friendly.

A simple small(Shimano like) display tucked away behind the handlebars with a max of 3 bits of information on screen at a time(there is a limit for the human brain). Battery level in %, Assistance level color coded, My input power, the rest of other info by choice on other possible screens.

I ride an emtb with the main info displayed on the downtube, It's one of the most uncomfortable places on an emtb to look at your information, it's also dangerous as it takes away your focus of the trail,...so this is a huge miss on the dji for me, not sure but It looks like no one is paying much attention to human ergonomics.

Everyone likes different things, wish you all the best with the bike, I will keep riding my enduro until there is something new that fits the box. 🫡✌️
 

Bengy22

Member
Aug 25, 2022
125
80
USA
Is it that one is measuring Electrical output and the other is measuring mechanical output at the rear wheel?
From my understanding ebike-mtb power figures were either at the wheel or tested at the wheel but then because they calculated for drive train losses removing them in their figure. I'm not sure which one they are referencing for there figure though. I don't know what the German testers use, maybe they are quoting at the wheel with losses and thus the large power loss? Here's the quote from the ebike-mtb site:

The laboratory test procedure​

There are different ways to test motors. For us, there was just one option worth considering: to test the motor system as a whole, i.e. in a complete bike, because that is the most realistic. And we were able to do just that at Velotech! Below, we’ve outlined the lab test procedure for all the nerds amongst us.

To prepare for the laboratory tests, we fitted all bikes with control tires running identical pressures, checked the drivetrains, and lubricated the chains. As a result, the energy losses incurred by the rear wheel and drivetrain should be similar. Then the bikes were clamped to a test rig, which looks a little bit like a large, industrial roller trainer, with a roller resting on the rear wheel. The cranks are turned by an external motor, with a continuously variable speed and power. The speed and power of the external motor simulates the rider’s pedalling power and cadence. Drivetrain losses and rolling resistance can be calculated and accounted for by pedalling the bike with the motor switched off at a certain input power and then measuring how much of that power is transferred to the roller. For practical purposes, however, it’s important to understand that the actual mechanical power put out by the rear wheel is what counts.

First, Velotech project manager and physicist Florian Edelmann helped us determine the power and support ratio of the motor. To do so, the pedals were turned at a fixed cadence while simulating a linearly increasing rider input power, allowing us to measure the electrical and mechanical power. We also had the motors in our eMTB motor comparison set to the highest support mode. Why? Only the highest mode is comparable, because this is where the motor performs at its maximum. All other modes differ from manufacturer to manufacturer, or may be tuned by the bike brand, and therefore don’t allow for an accurate comparison. In addition, the various modes offer numerous customisation options, which makes them even less comparable. The power curves we obtained during this test provide information on how much the electrical and mechanical power output increases, what the ratio is between rider input and motor output, how many watts of rider input are needed for the motor to unleash its maximum power, and, finally, at what power it reaches its limit.
 

Lexle

Member
Jun 4, 2023
71
67
Germany
Yep u are right they are different, are u surprised, well I am not.

Do you know each test bench standards(cadence, test duration, input power, tires, bike gearing, point of measuring(wheel or crank), is it electrical or mechanical power, weight, room temperature, etc..., most probably they aren't the same...

Yep the Brose almost doesn't derate, why don't you tell the reason also (it's in the video) let me say, because it has set an extremely high temp limit(can confirm myself) riding along my budy his levo motor heats up all the way to 89°C(we checked in app after a 1000m average 9% climb)...you could fry an egg on his motor.

Look, thanks but I don't need any info about the bike, I am not interested as there are no dealers no where near me, and even if there were,...

The trail geo just isn't my thing(it reminds me on the yt jeffsy), kinked seat tube is a no go, a phone display on an ebike, no thank you, if I ride I ride, I don't need a gazillion information when riding a bicycle and several remotes, all this and apps etc... it's just extra distraction and stuff that can break.

IMO an emtb only needs:

An ergonomic(towards the fingers tilted) simple small remote with haptic and/or audio feedback that has buttons for assistance levels and a on/off button, just dead simple and user friendly.

A simple small(Shimano like) display tucked away behind the handlebars with a max of 3 bits of information on screen at a time(there is a limit for the human brain). Battery level in %, Assistance level color coded, My input power, the rest of other info by choice on other possible screens.

I ride an emtb with the main info displayed on the downtube, It's one of the most uncomfortable places on an emtb to look at your information, it's also dangerous as it takes away your focus of the trail,...so this is a huge miss on the dji for me, not sure but It looks like no one is paying much attention to human ergonomics.

Everyone likes different things, wish you all the best with the bike, I will keep riding my enduro until there is something new that fits the box. 🫡✌️
I’m still riding a Kenevo with SMag and the derating Strategy Starts much earlier (1st step around 70 degrees ) than at 89 degrees in several steps and you can feel it significantly . I didn‘t write that the Brose isn‘t derating. I just showed up that the Bosch is not better than the others. Hence not having more power than species. Hence no “derating reserve “ to be pushed to 100 NM or 700 Watts.

As I’m a real heavy rider I get every motor in Derating.. and 13 minutes are a joke in any way


I Like Top Tube Displays. Everything mounted near Bar End or left or right beneath the stem distracts much more and the tiny Button of the Shimano is the biggest fail ever.. :)
 
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Lightme

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Jul 17, 2020
207
205
Sydney
Does anyone have any info on whether a range extender will be made available for this? Can't find anything online about it. It'd make the difference to me between ordering to 600Wh or the 800Wh.
 

Lexle

Member
Jun 4, 2023
71
67
Germany
Does anyone have any info on whether a range extender will be made available for this? Can't find anything online about it. It'd make the difference to me between ordering to 600Wh or the 800Wh.
Asked my dealer .. so far no, but I already wrote DJI that there will be a demand for it 😂
 

Suns_PSD

Active member
Jul 12, 2022
522
439
Austin
Been reading some real-world weights and rider experiences.

Have to admit, the hype seems pretty real.

Shame about the trailbike frame however.
 

irie

E*POWAH Elite World Champion
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May 2, 2022
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Paranoia in the extreme
From the above link:

Suing the Pentagon is the latest effort by a Chinese firm “to weaponize U.S. legal frameworks to undermine national security,” said Craig Singleton, senior China fellow at the nonprofit thinktank the Foundation for Defense of Democracies. “Ultimately, this lawsuit is a dead-end for DJI.”
 

DirkWisely

New Member
Jun 14, 2024
96
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California
From the above link:

Suing the Pentagon is the latest effort by a Chinese firm “to weaponize U.S. legal frameworks to undermine national security,” said Craig Singleton, senior China fellow at the nonprofit thinktank the Foundation for Defense of Democracies. “Ultimately, this lawsuit is a dead-end for DJI.”
I'm not sure how them selling mountain bikes or $200 drones on Amazon is a national security issue.
 

emtbeast

Active member
Jan 10, 2022
282
326
Slovenia
Maybe unrelated entirely, maybe not.

Gist of it is that the US DoD has designated DJI as a 'Military Company' which result in at least drone exclusions, but possibly all DJI products in the USA. DJI is suing to overturn the ruling.

Didn’t want to bring it up, not to disturb the fanbase, but yeah this was in the works for a while already...I guess it's in it's final phase.
And for anyone that knows just a tiny bit about how cyberwarfare today works(just now as we speak) and a bit about how Chinese government works wouldn't be surprised about the US steps being taken. Rember Huawei in EU with their 5G technology attempts...
 

DirkWisely

New Member
Jun 14, 2024
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Didn’t want to bring it up, not to disturb the fanbase, but yeah this was in the works for a while already...I guess it's in it's final phase.
And for anyone that knows just a tiny bit about how cyberwarfare today works(just now as we speak) and a bit about how Chinese government works wouldn't be surprised about the US steps being taken. Rember Huawei in EU with their 5G technology attempts...
I don't trust the Chinese, but we kind of fucked ourselves already. Our country would collapse in under a year without Chinese imports. They make everything. If they wanted to fuck us with their exports, they don't need DJI specifically to do it.
 

Emailsucks98

Active member
Nov 12, 2020
347
406
Bellingham Wa
I'm not sure how them selling mountain bikes or $200 drones on Amazon is a national security issue.
I think the point is that DJI is knowingly supporting Russia's war effort, and could be doing more to control their supply chain.

Ukraine is using them too, so I'm not here to say it makes sense. But there is no doubt hobby drones are being used as weapons.

It wouldn't stop me from buying an Amflow. But those 28 spoke wheels with EXO casing tires might!
 

sethimus

Member
Dec 31, 2023
127
114
Switzerland
I'll do better than that. I'll provide you with an exploded drawing. It's a Shimano SHIMANO SLX M7110. I've highlighted the hub.

If you knew of a HG hub that is that shape and fits. I'd really appreciate it.

View attachment 148525

uhm, hello und welcome to last week. you do know that the ukraine is producing its own drones quite succesfully? no need for these stock ones anymore...
 

Suns_PSD

Active member
Jul 12, 2022
522
439
Austin
I don't think it's just the warfare potential of drones, I think that it would easy for the Chinese government to map every square inch of the USA, military bases, water supply, population centers, etc. and for the public to do all of the work for them.

I think it's an obvious security issue.
 

sethimus

Member
Dec 31, 2023
127
114
Switzerland
I don't think it's just the warfare potential of drones, I think that it would easy for the Chinese government to map every square inch of the USA, military bases, water supply, population centers, etc. and for the public to do all of the work for them.

I think it's an obvious security issue.

yeah, thats why they had these huge ass ballons up there a few years ago. pretty silly if they still need to rely on drones too?

also:

maps.google.com
 

irie

E*POWAH Elite World Champion
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May 2, 2022
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I'm not sure how them selling mountain bikes or $200 drones on Amazon is a national security issue.
As I see it, it's to do with DJI's activities which potentially compromise US security. Perhaps you are not aware of the potential security issues inherent in the use of microprocessors in DJIs devices and that all Chinese companies if requested by the Chinese State are required under the provisions of the (Chinese) National Intelligence Law (2017) to "support, assist and cooperate with the state intelligence work". That is to say, if the Chinese state requests the information it must be provided. For the avoidance of doubt, that can be any information of any type.
 

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