Cycling UK Forum

B&M will start shipping a new dyno light at the end of the year,
so lots of used B&M 100lux and 70lux lights will be on the market.
Just in time for night time club runs.

scottg wrote: ↑5 Sep 2024, 5:34pm B&M will start shipping a new dyno light at the end of the year,
so lots of used B&M 100lux and 70lux lights will be on the market.
Just in time for night time club runs.

After catching up on this thread I'd just been checking the range! I'd guess that this is the "IQ-XL Highbeam":
https://www.bumm.de/en/products/dynamo- ... di-01.html?

All of our tourers now have dynamo B+M headlamps and I'd strongly recommend them for on-road use. Pre-loved should be fine.

Only a couple of problems: two failures of the model with built-in USB charging, and an impenetrable system of naming.

Jonathan

..I like the page which shows the differences in lux output.. and again drawing on my cynicism from the time spent learning marketing... its interesting that unlike the real world there is no other light source (car lights, street lamps, moon, etc) in the lux photos, and that whilst it's underground the pillars and the ceiling have all been painted white to reflect as much light back as possible.

Every day someone comes in and waters my cynicism...

cycle tramp wrote: ↑5 Sep 2024, 7:06pm Every day someone comes in and waters my cynicism...

It's impossible to represent in a photo the way the eye would see abeam of light, I don't think there's any fraud intended, and I think the photos still have validity as comparisons. No one is claiming you should use them a basis to judge lights than haven't been included, that would be daft.
Maybe this attempt to show different beans would be more to your liking, though it doesn't include some of the recent options:
https://www.peterwhitecycles.com/headlights.php

Using multiple LEDs is common practice in battery headlights. I don't know why it's not done in dynamos. Nor do I know if it really produces a wider or more even beam, considering the emitters are all behind a lens of say 5cm x 2cm. Tiny compared to the old (and fairly useless) Ever Ready Nightriders, let alone motor vehicle lights!

PH wrote: ↑5 Sep 2024, 7:40pm

cycle tramp wrote: ↑5 Sep 2024, 7:06pm Every day someone comes in and waters my cynicism...

It's impossible to represent in a photo the way the eye would see abeam of light, I don't think there's any fraud intended..

Maybe this attempt to show different beans would be more to your liking, though it doesn't include some of the recent options:
https://www.peterwhitecycles.com/headlights.php

I have to agree, I don't think there's any fraud intended, and I recognise its impossibility hard to photograph a spread of light from any lamp, accurately without the image being affected by the camera. However saying that, the light beam/spread shown in the b&m website is the optimum conditions for l.e.d s, which is why I love Peter White cycles website - as it gives people a 'real life' impressions of the light which is thrown and personally i feel that Cycling UK, should be taking up the baton and providing an equal critique of front lights which are available..
I also have to admit that I am sceptical of B&Ms pricing. I'm not sure why it costs 35 pounds to make a headlamp which produces 25 lux and almost 3 times as much to make a headlamp which produces 60 to 80 lux - yes, I understand the component parts would be more expensive.... but the construction time, packaging, transport costs are all the same.
I'm also surprised that they're still using one LED per headlamp. Around the fairly rural area where I live, several 4x4 vehicles have been fitted with additional led lighting, and in each case, it's a long thin narrow strip of leds.
..going back to rjb's experiments with household leds i'm also disappointed that so far there's not a manufacturer which has created a proper headlamp, with a focused cut off using these household leds..
Whilst I appreciate that leds have made cycling more accessible, more fun, and for many people, less hazardous, I'd be disappointed if the thrust of bicycle lighting continued down the "max power" route without addressing things like colour wash out, hot spots, price and ease of repair and replacement.

cycle tramp wrote: ↑5 Sep 2024, 7:06pm Every day someone comes in and waters my cynicism...

Maybe this would be more realistic for you?

https://road.cc/content/feature/roadcc- ... est-296975

It's a bit outdated, they tend to revisit it when the clocks go back and every cycling magazine / website starts running "what lights...?" grouptests.

rareposter wrote: ↑5 Sep 2024, 9:19pm ...
https://road.cc/content/feature/roadcc- ... est-296975

It's a bit outdated, they tend to revisit it when the clocks go back and every cycling magazine / website starts running "what lights...?" grouptests.

Thankyou. I don't think that I've seen that before.

Jonathan

cycle tramp wrote: ↑5 Sep 2024, 9:17pm I also have to admit that I am sceptical of B&Ms pricing. I'm not sure why it costs 35 pounds to make a headlamp which produces 25 lux and almost 3 times as much to make a headlamp which produces 60 to 80 lux - yes, I understand the component parts would be more expensive.... but the construction time, packaging, transport costs are all the same.

In the case of a dynamo, they're eking out more light from the same power, the higher powered light is likely to have more complex circuitry, it'll also do a better job of cooling, it's no coincidence that the better lights have metal cases. The original Edelux produced something like 30% more light from the identical diode and reflector in the B&M equivalent. Then there's volume, I suspect they'll make considerably more of the lower spec lights and as always there's an economy of scale. There is more to a light than it's illumination, the B&M IQ-X is IMO a better beam than the Edelux II, but it's spoilt be a horrible switch and a poor bracket. The SON lights have a better reputation for reliability, the reed switch is clever and adds to that, and it looks and feels like a quality item.

I'm also surprised that they're still using one LED per headlamp. Around the fairly rural area where I live, several 4x4 vehicles have been fitted with additional led lighting, and in each case, it's a long thin narrow strip of leds.

For most applications there just isn't the need, or advantage, where there is there are multi LED lights available.

cycle tramp wrote: ↑5 Sep 2024, 9:17pm ...
I'm also surprised that they're still using one LED per headlamp. Around the fairly rural area where I live, several 4x4 vehicles have been fitted with additional led lighting, and in each case, it's a long thin narrow strip of leds.

..going back to rjb's experiments with household leds i'm also disappointed that so far there's not a manufacturer which has created a proper headlamp, with a focused cut off using these household leds..
...

LEDs are not like filament bulbs, which throw out light in most directions. LEDs are very directional because they are made of flat layered semiconductors: less like point sources; more like blocks. LEDs have become much more powerful over time. They also need to be kept cool, so heatsink design has had to improve.



With those basics it is easy to understand why LEDs are the way they are. The first feeble ones used multiple emitters with simple hemispherical packaging pointing in slightly different directions to cast a diffuse beam. Then various people tried to design reflectors to deal with an emitter from which light emerges mostly forwards. These work poorly. You can add lenses, as Supernova does. Some people have diffusers, Fresnels and so on. B+M's breakthrough was to use a reflector that works well with a forward-emitting LED: the clamshell. With ray-tracing software you can design any beam pattern you like, and it is particularly well-suited to beams with a sharp cut off. The hot LED is at the top, which makes cooling a bit easier too.

LED vehicle lights are used for the non-directional day-running lights, decorative do-dahs and the indicators, I think. The focussed beam is usually a discharge lamp but you can buy parts with a few LEDs arranged in the form of a filament. Correct me if I am wrong.

Motor vehicles have two lights about 2m apart. That gives useful shadow cancellation. Two lights on a bike are so close together the advantage is small, unless you just want more light or it shining in a different place of course.

cycle tramp wrote: ↑5 Sep 2024, 7:06pm Every day someone comes in and waters my cynicism...

Eventually you become cynical about cynicism.

Bmblbzzz wrote: ↑5 Sep 2024, 8:36pm Using multiple LEDs is common practice in battery headlights. I don't know why it's not done in dynamos. Nor do I know if it really produces a wider or more even beam, considering the emitters are all behind a lens of say 5cm x 2cm. Tiny compared to the old (and fairly useless) Ever Ready Nightriders, let alone motor vehicle lights!

I have two Cateye front lights, one rechargeable and one battery. They both have a single led but give completely different beams. The rechargeable is rated at 100 lumens and gives a very even wide beam while the battery is 50 lumens and concentrates the beam in the centre. They both feel about the same brightness despite the rechargeable being double the lumens of the battery. So it seems that they can manipulate the beam to be wide or narrow. I assume that the battery light concentrates it's beam in the centre for the sake of efficiency.

Multi-LEDs for the dipped beam would add unnecessary complexity. As Plancashire notes, in cars these are usually the daylight running lights.

A reason why StVZO lights have avoided multi-LEDs may be because most of them have origins in dynamo lights. Early LEDs had a forward voltage in excess of 3V to light properly, while StVZO requires operation at 6V. Once you factor in voltage drop from a bridge rectifier, a simple series circuit of 2 LEDs would require too high a voltage (although, in practice that is no problem for the dynamo). In parallel would require some balancing circuitry, such as resistors, which would be inefficient. More complex circuitry could be used, such as boost converters or multi-LED drivers, but these add cost and are more for the expensive lights.

In any case, the main driver of the beam shape is the lens or reflector.

Regarding the higher power lights and B&M's marketing, I doubt they would lie about the actual lux measurement. A higher lux measurement can always be made by tightening the hotspot, but I don't think that's what the pictures show.

There is still quite a bit of leeway for manufacturers to optimise dynamo light output, and some of this is natural, as LEDs become more efficient (lumens per watt) every few years. Many lower to medium range dynamo lights still only produce 100-150 lumens which, at over 100 lumens per watt available nowadays, is not really using the 3W that the dynamo is specified for (and that doesn't necessarily mean they pull less power). Some of this is doubtless deliberate, as they need to maintain a product range.

Talk of multiple LED's has sent me down memory lane...
Does anyone remember the Solidlights? As far as I'm aware the first of the quality LED dynamo lights, these used multiple LEDs. Very niche small scale production, but the must have Audax light for a while.
https://www.meiring.org.uk/pdm/Audax/So ... view.shtml

Then the first of the reflected light type was from Inoled, a couple of years before B&M started doing so. I had one, but it wasn't without issue. I just googled them but one of the few hits was my own post from 2007!
viewtopic.php?p=59533#p59533

When did the big manufactures get interested? I'd swapped the Inoled for a Supernova by 2008, the original one with an unreliable toggle switch on the back, it spent more time back with them than it did on my bike, eventually they replaced it with the push button model.