DJI from China caused a stir in the bike scene. Seemingly from a standing start, the Chinese drone manufacturer presented an e-bike motor that outperformed all conventional motors. How was it possible that even the industry giant Bosch from Stuttgart was taken by surprise?
We spoke to Ferdinand Wolf. Ferdinand was a drone expert at Skynamics, switched to DJI and is now the front man for bike motor development. We spoke to him about charging times, the competition and what electric motors can't stand.
BIKE: A drone manufacturer from China comes along and mocks renowned motor manufacturers like Bosch. How can that be, please explain?
Ferdinand Wolf: Well, DJI is not a small company. We've been around since 2006 and there are around 14,000 people working at DJI, well over 3,500 in development, and the products we have on the market so far are technically very sophisticated and very successful. They are absolutely high-tech products. In short, we have an extremely high level of development and a lot of knowledge in this company.
But a drone is not an e-bike.
Drones and e-bikes are not that dissimilar. An e-bike has a battery with a battery management system. You have a motor that is controlled via ESC, i.e. an electronic speed controller. And you have sensors and software. All of this is also in a drone, which we have been developing for almost 20 years.
Maybe so. But Bosch laughs at 20 years of development experience. Bosch has been around since 1886 and today employs 420,000 people in 60 countries. The list of Bosch inventions is impressively long. And now rumour has it that DJI also wants to shake up the camera business and compete with giants such as Canon, Nikon and Sony.
DJI has been in the camera business for a long time. The Netflix series "Adolecence", which is currently taking off, was shot entirely on DJI cameras. There are Hollywood productions that film exclusively with DJI cameras. But to your question - I don't know if you've ever been to China - the development clock works a little differently here.
In China, the development clock ticks a little differently - in fast motion
What makes her tick?
In fast motion. One year of development in China is 4 to 5 years in Germany or Europe. When it comes to drones, the layman may think: it's a plastic box with four propellers. But drones are highly complex, high-tech products.
You say that drones and e-bikes are similar. Both should be light, robust and powerful. What is the biggest challenge if you want to build a good e-drive?
With drones and stabilisers, you have brushless motors. So-called direct drives. The challenge with the bike motor was that we needed a gear reduction stage. But our engineers were quickly able to solve this with a planetary gearbox. Another challenge was that the motor had to respond to the rider's input. In other words, the interface between rider and bike.
This is exactly where it is decided whether an engine is rated as good or not.
That's right. We are particularly proud of this interface. Everyone talks about the performance of our motor, but riding enjoyment depends more on how sensitive and natural the motor assistance is. This is where we can show off our extensive experience in the field of sensor technology. Thanks to our high sampling frequency, we know exactly what the rear wheel is doing. We have developed special software that can react extremely sensitively. You can adjust the support levels precisely to your needs.
Is this the real strength of the DJI motor?
Yes, because it's no use having the best hardware if the software isn't good - and vice versa. I like to compare this with Tesla or Apple. Because they build the hardware and the software. And we do the same with our bike drives. We do everything in-house. The person who develops the hardware sits a few desks away from the person who develops the software. We are hard to beat in that respect.
And what can Bosch do better than DJI?
You'll have to ask Bosch (laughs).
One thing was particularly surprising about your drive - the extremely short charging time. With competitor engines, you have to eat five Kaiserschmarrn at the hut and still nothing is charged. With you, on the other hand, charging takes no time at all. Why is that?
I suspect that the manufacturers have rested on their laurels. Since no one else has tackled the issue, they probably didn't feel compelled to do so. Everyone else has access to the cells we use in our battery. The charging technology is also known. All our products have it. And these charging technologies can be accelerated.
I would have thought that the war in Ukraine would have accelerated the development of drones.
The technology already existed before. It has nothing to do with the war in Ukraine.
But drone development was driven by the war.
That may be true, but DJI does not build military drones. We only make products for the civilian sector. The war hasn't really changed much for the civilian drone world.
Before DJI, you worked for the drone manufacturer Skynamic. Are you a mountain biker?
I grew up in the Odenwald and practically grew up on a bike. I started with BMX, then MTB, and now I'm on my bike almost every day.
What is important to you about the EMTB?
I want: 1. ease of use. It used to be cumbersome. Thanks to our system, it is now state of the art. With a touchscreen and self-explanatory use and good readability. 2. fast charging technology. I live in Germany. You never know what the weather will be like tomorrow. I often don't fully charge my battery - it's not good for the battery if you leave it full. With our charging technology, I can charge the battery to 85% in 1.5 hours. 3. i want a powerful but quiet motor with a sonorous motor noise. 4. i want to configure the system without using my mobile phone.
You're a mobile phone grouch.
In nature, yes. I don't want to have to use my mobile phone there. I'd prefer to leave it at home; I only take it with me to take a group photo at most. I often ride with friends. To do this, you have to synchronise the engine power. I can do this very easily on the touchscreen of our drive - without having to pull my mobile phone out of my pocket.
"A huge block as an engine and another block as a battery - I never liked that."
Does the weight of an e-bike play a role for you?
Not just the weight, but also the dimensions. The first e-MTBs were bulky hulks. I come from organic biking, like all of us who have been mountain biking for a long time. That's why aesthetics play a decisive role for me. A huge block as a motor and another block as a battery - I never liked that.
This is why minimal-assist bikes are so attractive.
Exactly. Before the E-MTB project at DJI, I wanted to buy an e-bike. And I was flirting with the minimal-assist bikes, after all, I wanted to ride a bike and not a motorbike. I like to jump a lot - a bike weighing 25 kilos behaves very differently to a bike weighing 20 kilos. But the limited range of the light eMTBs bothered me. Not the weaker motor power, but the limited range.
And the DJI motor is supposed to do that?
That is our goal: we want to combine the look and weight of a light eMTB with the power of a full eMTB. I believe that we have succeeded quite well. That's why the DJI has caused such a shockwave in the market. We have shown that it is possible to build a lightweight motor that develops enormous power. So 1000 watts with an 800 watt battery. That's why the Amflow has generated such headlines and now other brands are equipping their bikes with our motor.
Is this the death of light eMTBs?
I think so. Because that means there are no longer any arguments for doing without engine power.
And arguments in favour of a normal bike? Make a prediction, will developments like yours reduce organic bikes to a niche existence?
The light eMTB market will indeed have a difficult time in the future. People have no desire for reduced performance and range. Extenders are too cumbersome. People want a bike that combines decent performance with range. Biobikes will become niche. But for bike park riders, for example, biobikes will remain interesting. Personally, if there's a lift, I prefer to ride an organic bike, a Propain Spindrift. And for everything else I use my EMTB. Especially here in the Rhine-Main region, trail parks without lifts are springing up everywhere. You have a lot of fun there with an EMTB. That's brilliant. I can ride for as long as I want. The battery lasts. I'm flat before the battery is flat.
You are known as a tech nerd. What is particularly hard on an engine?
Anything that happens suddenly puts a strain on the structure. Imagine a rusted screw. You can't loosen it with high pressure alone, but with a jerky movement. This is why we have focussed on particularly sensitive motor control. Because then even high motor power can be easily controlled. A sensitive motor protects the drivetrain, even at high power.
Even with 1000 watts?
Even with 1000 watts. Our tests have shown that the motor is robust enough to deliver 1000 watts of power continuously - without causing any problems.
The fear: E-MTBs could be categorised as motorbikes
Keyword: 1000 watts of the DJI motor . Other manufacturers reacted as if they had slaughtered the sacred cow. In other words: DJI is jeopardising the status quo of E-MTBs. The fear: With more power, e-MTBs could possibly be categorised as motorbikes.
We want sport to remain safe and for everyone to be able to enjoy it. We comply with all current laws. For us, the biggest safety factor is the speed limit. That is 25 km/h. The power peak of the motor is not so important for safety. After all, we primarily ride fast downhill. That's where we often get into trouble with hikers. You can ride downhill just as quickly with 500 watts as with 1000 watts. And when it comes to safety, it doesn't matter whether you go uphill with 800 watts or 1000 watts.
And the torque?
The torque would be more relevant than the wattage. But again, it's more about the motor control than the peak power. You can have a system with 750 watts, for example, but if it is not sensitively controlled because it only has one sensor that comes through per wheel revolution, then the wheel will jump away from you. And there are these systems on the market. We, on the other hand, have integrated many safety systems. By the way: If the 1000 watts are too much for you, you can turn the motor down - with just one click.
So far there was only the Amflow with DJI. When will other brands be available with your motor?
The first smaller brands are already equipped with DJI, such as Unno, Forbidden and Megamo. And now, for Eurobike, more partners have been added that use the DJI Avinox drive, such as Commencal, Rotwild, Crestline, Crussis, Steppenwolf and Olympia. And of course there will also be new motor models.
Where do you see potential for improvement?
Everywhere: engine noise, interfaces, performance and, of course, price. We want to offer a favourable motor alternative so that manufacturers can lower the entry-level price. In short, we are looking in all directions to make complex technology accessible to everyone.
That sounds like an advertising slogan.
Maybe, but that's the way it is. The best example: our drones. We were the first to succeed in building a drone for everyone. The motto: open the box, charge the battery, fly away. You didn't have to read through a thousand instructions, watch tutorials, screw, solder and train.
What about the competition?
Perhaps she had rested on her laurels. (laughs). But competition stimulates business and drives innovation. I strongly believe that the competition will follow suit. Personally, I'm pleased that the fire of innovation, which had burnt down a little, is flaring up again. It's certainly great for the customer.
What innovation would you like to see in biking?
I find an integrated gearbox interesting. Like Pinion. The classic cassette gear concept annoys me. Even if Sram and Shimano have developed it further. Nevertheless, the rear derailleur gets dirty and clogged with mud. After a day in the park, the gears no longer run smoothly. Or the rear derailleur takes a knock - also annoying. Nobody likes cleaning the chain, and cleaning the cassette is just as bad. That's why integrated shifting concepts are exciting in my eyes. I would like to see this innovation. But at the moment the solutions are not ideal. The chain and cassette are still ahead.
Many push aids on E-MTBs are laughable. You almost break your fingers, yet they don't work properly.
Have you tried ours yet? Our pushing aid is much better. We have a tilt sensor, which is helpful. Or the function that allows you to change gear quickly by double-clicking. You just have to lift the rear. If I get stuck on a hill with a gear that's too high, I don't get off, I pull the front brake, lift the rear wheel up and with a double-click I can let the motor spin so that it shifts to an easy gear.
Yes, sometimes you get the suspicion that the engineers don't even try out the functions of their engines themselves.
We listen to the bike manufacturers, the OEMs (Original Equipment Manufacturers). This is very important to us because they know the feedback from buyers and know what customers want in practice. We have also implemented feedback that came in via our Facebook page. In the next update, you can set the battery to only charge to 80 per cent so that you don't have to get up at night. Or you can set the support modes directly on the display, without a mobile phone or app.
What else might interest you
Dimitri Lehner
Editor
