Note: The Suicycle bike shop in Hamburg contacted me and offered me a demo sample of the SON Ladelux for testing. Of course I did so and then returned it. Thanks again for that!
A note in advance: I am not an expert when it comes to electrical voltage, power, lumens or lux. For me, these are numbers that I am happy to take note of, but I can’t really do much more with them. I look at the subject of lights on bicycles purely from a practical point of view and therefore also judge light output and lamps according to their practical use for my type of cycling.
If you are interested in measurement curves, voltage overviews and laboratory reports, then you need to look elsewhere. For example, in the magazine Fahrrad Zukunft (in German only), which discusses such topics in a very nerdy and competent way and whose credibility is also demonstrated by article titles such as ‘Bicycle headlights – spectral properties and effects’. You’ll have to rummage through the issues. It’s worth it in any case.
Or at Fahrradbeleuchtung.Info (in German only), where Stefan deals very competently with bicycle lighting and power supply on bicycles and tests a lot.
And also at Torsten Frank, who has tested a few lights in the last few weeks and will certainly be writing a lot about them on his blog soon (German and English).

But at least I would like to clarify the terms lumen and lux, because they often appear in the following text. And manufacturers sometimes use one, sometimes the other. Or both.
Lumen essentially means the total amount of light emitted by a lamp. Put simply: the more lumens, the brighter. But: a lot of lumen does not mean that the lamp is bright enough for the application. Simply having a lot of light doesn’t help much. It therefore depends on the optics of the lamp in question and how it focusses the light beam and directs it onto a specific surface.
And this is measured in Lux. There are often specifications such as 1 lux corresponds to 1 lumen per square metre. So if a lamp has 170 lux, that would be 170 lumens (light intensity) per square metre. But that doesn’t really help me, because I can’t imagine that, especially as I don’t know how far away the illuminated area is, what the angle is, how the light is distributed and how much light is ‘swallowed’ by the surroundings.
Therefore, any discussion about light is actually very subjective from the outset and you would first have to get a personal impression of each light.
In the run-up to this post, I also did a survey on Instagram and asked, among other things, what is important in good light:
- That it is properly bright.
- Wide and uniform light distribution.
- Little scattered light upwards.
- Good illumination.
- A nice large, even carpet of light.
- Uniform illumination.
- Plenty of light.
- Uniform light pattern.
- It should be damn bright.
This clearly shows that the requirements make it difficult to assess a light correctly, because all of the above are very subjective statements and what is good illumination for me may not be optimal for someone else.
So much for the preliminary remarks.
My long road to light
As a touring cyclist, light was not an option for me for many years. I simply didn’t need any light, because I was usually only travelling in daylight on my tours and when it got dark, a torch helped. Today, of course, I see things differently.
Then I had a Norwid touring bike built and naturally opted for lights and a hub dynamo. I chose the SON Edelux II as my light, which was the non plus ultra at the time. And its light was sufficient for travelling on roads and paths. However, I mainly used it when commuting to the office to see and be seen.

However, the first time I really got to grips with lights was during the Atlas Mountain Race. As we had to ride through the dark a lot back then, I needed a light. I decided in favour of the Busch & Müller IQ-X. With its 100 lux, it wasn’t bad and I found it better than the Edelux. This was mainly due to the fact that the light field was not quite as angular as the SON and simply offered me better visibility off-road.
And that brings us to the topic and, so to speak, the final enemy of any good light: off-road riding. This is simply subject to different requirements than when riding on roads and paths. Here, you need a lot of light in the immediate area in front of the bike as well as illumination beyond it in order to recognise what is coming and where the track is heading.
Off-road, however, often means pushing. And this is where the IQ-X naturally reached its limits, because as soon as you stop or push slowly, the light is gone. In addition, the IQ-X (like the Edelux) tended to flicker at low speed, which of course doesn’t help anyone when you’re slowly cranking up a mountain in the dark (and it was often very dark in Morocco) and trying to find the best line between the stones in the flickering light.

Of course, I had a powerful headlamp with me then as I do now, which made it easy to navigate.
Back from Morocco, in preparation for the Silk Road Mountain Race, the right light was of course also an important issue for me. Especially in conjunction with a hub dynamo for the power supply on the road.
The lighting solutions available in Germany at the time were not really suitable for my requirements, which is why I looked across the border to Australia. Klite, a well-known manufacturer of very powerful bicycle lights for use with hub dynamos, is based there.

With the Bikepacker Pro, the Australians had a lamp with 1,300 lumens on offer that had already proven itself in such ultra races. And it had the advantage that the lamp can be connected to a Klite USB charger. That was interesting for me, because I was looking for a powerful charger and light that harmonised with each other and could be switched.
I then bought the Klite Bikepacker with USB charger for around 450 euros and not only successfully mastered Kyrgyzstan with this combination, but also many thousands of kilometres afterwards. I was not only impressed by the light, but also by the performance of the USB charger. Even in the mountains, when things were really slow, I was always able to charge my Wahoo GPS and sometimes my iPhone with the charger. In any case, I was always able to keep the phone’s battery level stable in the mountains.

When I built myself a new bike for the Trans Balkan Race, I also wanted to test another light: the Sinewave Beacon 2. I’d had this on my list before, but it wasn’t available at the time. The Beacon also has a USB charger, but it is installed directly on board in a small and slim lamp body. It has a switch on the back that can be used to switch the light off, switch to low beam or full beam.
Incidentally, many people consider an on/off switch to be an important criterion for a good light: 83% of those I asked on Instagram explicitly wanted this.
With a maximum of 750 lumens, the Beacon is not quite as bright as the Klite, but like the Australian light, it creates a wonderful carpet of light, which also illuminates everything around it and thus provides enough safety off-road, even when things are moving faster.

But if I have to push, or if I’m going uphill more slowly, then the Klite and the Sinewave also dim. However, neither of them flicker and at least provide enough residual light for me to see enough when I’m travelling slowly or pushing.
But here too, more light would be desirable, because sometimes I just want to be able to see where I’m going when I’m standing. And a brighter parking light would of course help a lot. With the Sinewave, I can simply connect a power bank, which then provides me with the appropriate parking light. But this is also only a diversion solution.
For the sake of completeness, however, I must mention that neither the Klite nor the Sinewave are road-legal in Germany (StVZO), which is why they cannot be bought here.
For a long time, these were the two real alternatives to battery-powered lights, such as a Lupine, Supernova or Exposure, especially if you wanted to combine power supply with light on the road without having to recharge thanks to a hub dynamo.
Speaking of batteries: 35% of the respondents in my survey favoured battery-powered lights. 37% favoured dynamo-powered lights. And 28% don’t care how the light on their bike shines.
Let there be light in the country
But then things started to move in Germany and Supernova introduced the M99 DY Pro, a dynamo-powered light that was more powerful than ever before with German road approval: up to 1,000 lumens and 200 lux light output with a 6V power supply.
Another new feature was the high beam, which could first produce 1,000 lumens/200 lux. It is switched on via a button and continues to light up even when the bike is stopped (not indefinitely, of course, but as long as the internal battery lasts). In normal mode (low beam), the M99 DY Pro produces up to 700 lumens and 200 lux, which is also quite bright (depending on speed, of course).
Speaking of which: The issue of road approval in Germany is viewed differently in my survey on Instagram: for 48%, StVZO conformity is important. Not for 52%.
For the sake of completeness, it must be mentioned here that there were of course already powerful lamps with road approval – but with a rechargeable battery. First and foremost the Lupine SL-AF or the Supernova Airstream or B54. But this is about dynamo-powered lights.
The M99 DY Pro is actually a great light, especially for ultra rides and bikepacking. And so many influencers advertised this lamp and were enthusiastic about the light output and the high beam. I’m happy to believe them – but for me, there was one decisive criterion missing for a ‘real’ ultra light: the ability to charge and be combined with a USB charger.
In my survey on Instagram, 71% of respondents wanted a light with a charging function.
Unfortunately, the Supernova is not designed to be combined with a USB charger, even though DIY solutions are already available. If they were to incorporate this, it would really be a true ultra-light.
New from Tübingen: the SON Ladelux

But in the middle of last year, there was first a rumour and then the certainty that SON was working on a lamp that would not only be at the forefront in terms of brightness, but would also include a USB charger that would also be particularly powerful.
The name of this innovation: SON Ladelux. And here nomen is omen, because this new lamp combines luminosity with a charging function.
The pure values promise a lot – if you can find them. SON is keeping a very secretive approach to the new lamp. There is only a thin reference to the lamp on the website and no real product page yet. In addition, it is currently only available from selected specialist retailers and is also fitted there.
Thanks again to Suicycle Hamburg for the testing opportunity.

According to the manufacturer, the Ladelux provides 120 lux in the low beam. The integrated high beam is new. You can switch it on with a switch and get an output of 180 lux. This is made possible by a 1,200 mAh battery inside the Ladelux.
This is charged during the ride and the high beam can then be switched on at the touch of a button. It takes a short time until the battery is full enough to allow you to ride in high beam mode for a long time. In practice, this lasts for several hours, as the battery is constantly being recharged.
In my survey, the high beam function was an important aspect of a good light: 61% want a high beam, 25% don’t care.

And here we can stay in practice: at first I was sceptical as to whether the Ladelux was really as excellent as I was told. But in fact, once correctly fitted and aligned, it was impressive.
In low beam mode, it illuminates the road or path normally. Just as you would expect from a normal headlight. I noticed the light field positively. It is quite wide, illuminates the edges well and, above all, does not have the hard edge at the front that the Edelux has, for example. This allows you to see a little further ahead when off-road and gives you an idea of your surroundings.

In high beam mode, the Ladelux really shows what it’s made of: the light field is even larger and wider and provides very good visibility even off-road. I was really impressed, even though I actually wanted to find my Sinewave better. But the advantage of the Ladelux is that the built-in rechargeable battery keeps the light shining brightly even when the bike is stopped and therefore provides a lot of light.
I tested the Ladelux extensively at the Leipzig Orbit in December, where I had to ride more than 100 kilometres in the dark.
You can get an idea of it here:
In this video there is a situation where the Ladelux failed and didn’t switch on for 30 minutes. I discussed this with Suicycle and it was probably still due to the old software of the test model, which had not yet had the latest update.
So you see, lamps are now also getting software that receives updates. However, this is currently still done directly via SON (via specialist dealers). But I expect that at some point you will be able to update them yourself (via computer).
After 30 minutes, the light worked again, but had problems switching between low and high beam. But that also worked again at some point.
Dennis, who is also currently travelling with a demo model of the SON Ladelux, noticed the same phenomenon with the light failing and then remaining on high beam despite the low beam being displayed. Incidentally, his weather conditions were almost the same as mine: cold, light rain/snowfall, damp. But that could also be a coincidence.

But that’s what tests are for, to find such sources of error in practice and then rectify them. And it also shows why SON is currently still acting cautiously, as they naturally want to deliver a finished and fully functional product.
So anyone who has already ordered a Ladelux can relax. It will all work and the final software versions will certainly fix this. And they should, because the Ladelux is supposed to cost around 480 euros.
But that doesn’t surprise me, because that puts the Ladelux on a par with comparable lamps and it remains to be seen what the street price will be.

But that’s not all, the Ladelux can also charge. And apparently better than any other lamp/charger to date: according to SON, the Ladelux manages to get 12 watts of power from the hub dynamo. Charging is actually very fast. I connected my iPhone with 86% battery and after 30 minutes the device was at 100%. Of course it depends on the speed, but the power is impressive, especially as you can charge and light up at the same time without any visible loss of light from the lamp. On Rennrad-News you can see a few power curves that were shown at the presentation of the SON.

A SON cable with a magnetic head is connected to the button for charging. SON then offers a cable with a corresponding plug depending on the end device. I had a cable with USB-C, the length of which was sufficient to get from the button on the aerobar to the top tube pocket without stretching.

However, I also have to criticise the charging cables, as they are special and can’t simply be replaced on the go if damaged. This puts you in a proprietary system. In comparison, the chargers from Klite or Sinewave offer a normal USB connection.
The second point of criticism is the mounting of the switch itself. This is done using a metal cramp, which has a thread at the end.

This end is then screwed to the switch. A small knurled screw is used for this purpose. But be careful: this screw can also fall out if you want to move the switch. Basically, I think this solution is simply too delicate and overly complicated, as a normal fastening with a rubber or clamp would be better in my opinion.

In practice, nothing has happened, except that the knurled screw came loose once, presumably due to off-road riding. Hence my point of criticism here.
However, the button itself works well. It is not a classic button that gives feedback when pressed. The button is used to switch on the light. A green light then lights up, which stands for low beam. If you are charging a device, the green light flashes during the charging process. If you switch on the high beam, the diode on the button lights up blue. If you are charging a device and the light is switched off, the diode lights up white. Occasionally it has flashed orange, but I don’t know what that means. It was also just before it went out – which I described above.

The push-button and lamp are connected by a plug. This connection is very tight. A jack plug is used on the hub dynamo. This is then plugged into the contact adapter. Both can also be retrofitted, even if you don’t have a Ladelux.

A rear light can also be connected to the Ladelux. There is a second plug cable on the light for this, but I have taped it off.

Conclusion SON Ladelux
As you can see, I’m impressed by the Ladelux and have to say that I’m actually considering a change. In addition to the excellent power output from the hub dynamo, I was impressed by the light output and the light image.
I have travelled many kilometres in the complete darkness of various heathlands north of Leipzig with this light. And I didn’t always need the high beam, because the 120 lux of the low beam is already very good.
If you then switch on the 180 lux, it becomes amazingly bright and the carpet of light spreads out evenly. You can see this in the Instagram video above. And also in the picture here:

The SON Ladelux measures 65 mm in length, 55 mm in height (with retaining eyelet 60 mm) and has a diameter of 48 mm.
The housing is made of high-quality aluminium (which does not get warm or even hot, even in high beam mode). It is very well made, as is the switch/button, which is also made of metal/aluminium.

The shape reminds me of the design of the 1920s. It looks like part of a Zeppelin, which is also iconic. The Ladelux is larger than the Sinewave, which is 58 mm long, 42 mm high and 42 mm in diameter.

The design is an important issue, because 74% of the people I asked on Instagram said that the ideal bike light should be compact.

And the SON Ladelux certainly is, even if it is slightly larger/bulkier. But that is subjective and depends on which light you come from.
The weight of the SON Ladelux is 178g, but this includes the switch, mounting, dynamo cable and USB-C charging cable. This makes it similarly lightweight to the competition. (Unfortunately, I forgot to weigh only the lamp itself).
In my survey, only 32% said that the weight of a light is important to them. It is not important to 68%.

However, the Ladelux cannot yet fulfil one important criterion: upside-down mounting. This is important to 68% of respondents. This means that the light can also be mounted ‘upside down’. In other words, on top of the handlebars or under the handlebars. This requires an LED and mirror arrangement that allows this.

The Ladelux is currently only available in black, but I am sure that other colours will follow after a successful market launch.
So if you’re looking for a light that is not only really bright (and within legal limits), but can also charge powerfully, then the SON Ladelux is currently the only light that can do this.

I’m curious to see if Supernova will follow soon and (finally) add a charging function to their M99 DY Pro.
Have any of you been able to test ride the SON Ladelux? Please write your experiences in the comments.