Author Topic: Dynamo lights  (Read 10874 times)

quixoticgeek

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Dynamo lights
« on: 08 November, 2017, 07:15:06 pm »


I was thinking of treating myself to a supernova e3 pro 2 dynamo light. But comments in a recent thread have given me doubt.

In the upto €150 area, what are the best dynamo lights? As I'll be cycling year round, I'd like one with a capacitor for stand light, rather than chemical battery, and it needs to be legal in germany. Other than that I don't have many requirements.

What do people recommend?

J
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BrianI

  • Is it a bird? Is it a plane? No, it's Lepidopterist Man!
Re: Dynamo lights
« Reply #1 on: 08 November, 2017, 08:32:06 pm »


I was thinking of treating myself to a supernova e3 pro 2 dynamo light. But comments in a recent thread have given me doubt.

In the upto €150 area, what are the best dynamo lights? As I'll be cycling year round, I'd like one with a capacitor for stand light, rather than chemical battery, and it needs to be legal in germany. Other than that I don't have many requirements.

What do people recommend?

J

Something from Bumm.de? e.g Cyo Premium? https://www.bumm.de/en/products/dynamo-scheinwerfer/produkt/1752qtsndi.html?  Will you be using the light on or off road mainly?

Re: Dynamo lights
« Reply #2 on: 08 November, 2017, 10:10:30 pm »
Edelux II
Fab light and able to colour code with bike!

quixoticgeek

  • Mostly Harmless
Re: Dynamo lights
« Reply #3 on: 08 November, 2017, 10:20:45 pm »
Confusingly some manufacturers measure their output in lux, some in lumens. The supernova claims 205 lumens. The b&m claims 80, and the edulux ii I can't find a number on...

As for use. I'll be using it for both road and off road. I currently use a hope vision 1. Which is a bit under powered down hill in the dark.

J
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Beer, bikes, and backpacking
http://b.42q.eu/

Re: Dynamo lights
« Reply #4 on: 08 November, 2017, 10:41:45 pm »
Cyo Premium (80 lux not lumens) - I wouldn't bother with the daytime running light version. Cheap and good, but plastic.

B&M IQ-X 100 lux. Not cheap and good.


Schmidt Edelux 2 90 or 100 lux, doesn't matter. Not cheap, good and beautiful.

Kim

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Re: Dynamo lights
« Reply #5 on: 08 November, 2017, 10:56:31 pm »
Lux is a more meaningful measurement (in as much as you can sum any of this up in a single number), but it assumes a specified aim, and is generally only used by the German manufacturers following the StVZO requirements.  Lumens are simpler to calculate, and are generally bigger numbers, so tend to be the headline figures that most manufacturers use (in a manner comparable to cameras and megapixels, where the performance of the attached optics are disregarded).

Pragmatically, the best way to compare lights is by riding on an unlit road with someone who's got one.  Failing that, decent photos of beam shape like those at http://www.peterwhitecycles.com/headlights.php

Features other than performance are somewhat easier to compare, though it's always hard to judge reliability.  I'll generally trust the opinions of audaxers and all-weather commuters who say a given light is reliable, but selection bias makes it hard to draw conclusions (other than probable failure modes) from negative reviews.


As for specific recommendations, I'll second sojournermike on the Cyo Premium series.  It's a substantial LED/optics upgrade on the non-premium Cyo, which is a proven design.  It probably represents the best price:performance ratio.

I also have the IQ-X, and while it certainly gives you more light than the Cyo Premium, it's a lot more expensive.  For me, the killer feature is a beam wide enough that you can safely ride recumbents round tight corners with.  There's a known switch problem with the IQ-X, though so far this seems to be a fault that's sometimes present from new, rather than one which develops over time.  Otherwise, it's still a bit new so hard to judge long-term reliability.  I think the IQ-X's double-articulated plastic bracket is stupid (unless you're trying to weasel round a rim brake), and have used the much simpler Cyo bracket on mine.

Hard for me to justify the cost of the Schmidt stuff over the equivalent B&M for something that - no matter how well-engineered - is likely to fall victim to Moore's Law.  Your shiny things budget may vary.

Re: Dynamo lights
« Reply #6 on: 09 November, 2017, 12:23:38 am »
Edelux II
It's basically a slightly souped up Cyo Premium in a shiny, weatherproof housing.

Lumens are simpler to calculate
Ho no they aren't!

To get Lux, you just stick a light meter in front and make a direct measurement.
To get Lumens, you've either got to measure them, which means measuring Lux in all directions and integrating up, or measure the current you are putting through the LED and looking it up on the LED manufacturer's spec sheet, making assumptions about emitter temperature and how much light gets lost inside the light and never makes it out the front.
Most makers (including Supernova) take the second approach, dealing with the assumptions by ignoring them, and consequently very frequently quote lumen numbers that don't stand up to checking.

Kim

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Re: Dynamo lights
« Reply #7 on: 09 November, 2017, 12:25:32 am »
To get Lumens, you've either got to measure them, which means measuring Lux in all directions and integrating up, or measure the current you are putting through the LED and looking it up on the LED manufacturer's spec sheet, making assumptions about emitter temperature and how much light gets lost inside the light and never makes it out the front.

Like I say, simpler to calculate.  You can do that without measuring anything.  Sure, it'll give largely meaningless numbers, but for marketing purposes they just need to be nice and big looking.

quixoticgeek

  • Mostly Harmless
Re: Dynamo lights
« Reply #8 on: 09 November, 2017, 09:43:24 am »
Edelux II
It's basically a slightly souped up Cyo Premium in a shiny, weatherproof housing.

Are the Cyo lights not so weatherproof? Given the Dutch weather I should have perhaps listed weatherproofness as a requirement.

I like the look of the Edulux II, based on the photos from the peter white site. That's now top of my list...

J

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LittleWheelsandBig

  • Whimsy Rider
Re: Dynamo lights
« Reply #9 on: 09 November, 2017, 09:54:51 am »
The Cyos last for many years (I've not killed one yet). The water drains out faster than it gets in. The black paint eventually bubbles off the aluminium heatsink though.
Wheel meet again, don't know where, don't know when...

Dave_C

  • Trying to get rid of my belly... and failing!
Re: Dynamo lights
« Reply #10 on: 09 November, 2017, 10:03:21 am »
Another vote for B&M lights. The meet German regs, work for years (excluding earlier models with USB charging - where the USB stopped but the light continues to emit light), bright enough for riding in the darkest places in Scotland, but also bright enough for the street lit roads of Edinburgh, they have a shaped beam, so direct the light where it is needed, not wasting it shining up at the sky.
@DaveCrampton < wot a twit.
http://veloviewer.com/athlete/421683/

Karla

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Re: Dynamo lights
« Reply #11 on: 09 November, 2017, 12:05:15 pm »
they have a shaped beam, so direct the light where it is needed, not wasting it shining up at the sky. which is a poor design feature that makes the light appear brighter than it is by directing all the light into one little box in front of you, so you can't see round corners and can't even see someone's feet if they're above the beam throw.  The lights are all the worse for it, despite being loved by people who have a pathological fear of directing even a single photon into someone else's eyes, because they're ignorant of physics and don't realise that's how we actually see things.

FTFY

Kim

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Re: Dynamo lights
« Reply #12 on: 09 November, 2017, 12:18:10 pm »
Edelux II
It's basically a slightly souped up Cyo Premium in a shiny, weatherproof housing.

Are the Cyo lights not so weatherproof? Given the Dutch weather I should have perhaps listed weatherproofness as a requirement.

Between us, barakta and I have had 4 Cyos of various specs.  One of those eventually broke at the plastic where the mounting bolt attaches (but is electronically fine), after about 10000 miles (of which a significant proportion was typical British cyclepath style off-road, on a bike with a nasty rigid fork).  Over-tightening cant' be ruled out.  The other three are still going strong.  None have ever had a fault due to water ingress.  The one that was until recently on my tourer, in particular, has been exposed to serious rain for prolonged periods, both while riding with the light on, and while parked outdoors.

Kim

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Re: Dynamo lights
« Reply #13 on: 09 November, 2017, 12:37:38 pm »
they have a shaped beam, so direct the light where it is needed, not wasting it shining up at the sky. which is a poor design feature that makes the light appear brighter than it is by directing all the light into one little box in front of you, so you can't see round corners and can't even see someone's feet if they're above the beam throw.  The lights are all the worse for it, despite being loved by people who have a pathological fear of directing even a single photon into someone else's eyes, because they're ignorant of physics and don't realise that's how we actually see things.

That's a harsh but not entirely untrue assessment of the original IQ reflector (IQ Fly, Ixon IQ, 60Lux Cyo and derivatives) when mounted at 700c fork crown height or above (it fares somewhat better at folder/low recumbent height).  The design is a consequence of trying to put as much light down the road as possible while conforming to the letter of the extremely strict StVZO regulations, rather than ignorance of physics.  As a first attempt at designing optics that use an LED light source effectively rather than treating it like an isotropic source, I reckon they did pretty well physics-wise.  It was a step-change in cooling the LED effectively without cooking the electronics/battery.

More recent models have improved matters by spreading the beam much further horizontally (and to a lesser extent vertically), so you don't get the same 'hotspot' effect that causes the area outside the main beam to be perceived as darkness, and you get more light where you need it on corners.  The 'T' model Cyos, Luxos and IQ-X use various strategies to provide an additional wider spread of 'be-seen' light outside (including above) the main beam.

I'll agree that StVZO-compliant lights aren't perfect for everything, in exactly the same way that a car's dipped beam (the optics of which are very similar) isn't perfect for everything.  If you're going off-road, then a wide conical beam is much better.  A tight conical beam can be useful on fast descents.  Head-mounted lights are always handy for reading maps and road signs.  There are even daylight conditions (I'm thinking heavy rain or time trials) where an obnoxious strobe might be appropriate for increased visibility.  But as a default option for road riding, the StVZO beam shape is is ideal.

An StVZO-compliant dynamo light, supplemented by some kind of conical-beamed torch (which you'll want anyway on a night ride to see with while stopped) is a good general-purpose solution.

Re: Dynamo lights
« Reply #14 on: 09 November, 2017, 01:15:58 pm »

Are the Cyo lights not so weatherproof?
 
As I understand it, the IQ Cyo and eg, the SON Edelux have different strategies against rain and condensation: The Edelux relies on tight seals and is protected from water ingress in any direction, while the Cyo have an actual drainage hole in the bottom while being waterproof everywhere else. So while the Cyo have a slight risk of water ingress, it isn't a real problem unless it is installed on a bike without mud guards. The huge advantage with the Cyo design is that it makes the light and its electronic parts, extremely well protected against even extreme swings in temperature and humidity since moisture can easily escape. The SON Edelux design can be problematic if the sealing fails since the condensed water have problems escaping which can cause corrosion of the electronic parts. SON consider water ingress a failure that is covered by their 5 years warranty.     
 
I think however, that there is very little practical difference between the IQ Cyo and Edelux design; both lights have proven to be very, very reliable, even when used in adverse weather.

IMHO, the IQ Cyo Premium is still the best value-for-money dynamo light (around 50 Euro).
The Edelux II is actually based on the B&M Cyo's reflector and electronics, but with better LED cooling and therefore higher lumens output. It also have a glass lens with optical coating and is overall clearly a more  luxurious design. Whether those improvements are worth the extra money is probably a personal matter depending on budget and usage.
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Samuel D

Re: Dynamo lights
« Reply #15 on: 09 November, 2017, 01:34:43 pm »
I have an unused Cyo Premium with a large crack in the plastic lens, just about visible in the photo here. (I nearly sold it to a forum member but noticed the crack when packing it for shipping.) It must have happened either in shipping from Germany (it was terribly packed by Bike24) or in my parts box. Either way, does anyone know if the lens can be economically replaced?

Re: Dynamo lights
« Reply #16 on: 09 November, 2017, 01:45:58 pm »
No problems with my Edeluxes, even when running underwater in a flood

Cyo weatherproofing topic:
https://yacf.co.uk/forum/index.php?topic=47502.0

A Cyo should be OK with its drain hole unless you run with no mudguards and/or mount it in a particularly spray-prone location. I'd expect wheel spray to be a worse problem than rain, not least because of added salt (in the near future).



Re: Dynamo lights
« Reply #17 on: 09 November, 2017, 01:53:23 pm »
Either way, does anyone know if the lens can be economically replaced?
I doubt it, unless you can persuade Bike24 or B+M to replace it for you.

A new lens won't be available without buying another Cyo, and I'd expect them to be glued in so that getting a lens off another Cyo would be liable to break it, at least as far as detaching fragments off the fit line.
You could try putting out a call for a non-working Cyo and try getting the lens off it.

I'd probably just use it as is, crack and all, so you could try putting it back on the market at a lower price, with crack advertised.

Re: Dynamo lights
« Reply #18 on: 09 November, 2017, 06:06:57 pm »
Quote
.... some manufacturers measure their output in lux...
NB When manufacturers of Stzvo compliant lamps quote lux ratings for their lamps, they actually mean X lux when measured at 10meters because a lux measurement needs a corresponding  'distance from lamp source to where measured'  value to be meaningful.*

Lux measurements can be converted to  BS6102/3's unit of choice, the candela (cd), with the following formula:
           Candelas = (lux * (DistanceFromSourceToMeasurementDeviceInMetres)^2)

so an 80lux Stzvo lamp has a max brightness of 80 * (10)^2 == 8000cd.


* for some reason  car headlamp lux values are usually  specified at 25m so such values are not directly comparable to Pedal-Cycle Stzvo ones  ???

Re: Dynamo lights
« Reply #19 on: 10 November, 2017, 10:28:55 am »
Another vote for B&M lights. The meet German regs, work for years (excluding earlier models with USB charging - where the USB stopped but the light continues to emit light)

Nope, the Luxos U is prone to the electronics failing as well, which causes the light to be difficult to switch on or to go flickery. It has some very complex fragile electronics (including a huge 32 bit CPU) and isn't particularly well sealed.

Samuel D

Re: Dynamo lights
« Reply #20 on: 10 November, 2017, 11:32:29 am »
What does it need a 32-bit CPU for?

By the way, the Busch + Müller lamps may be poorly sealed in part to promote air cooling. Effective LED cooling, however that is achieved, is critical to good performance.

Dave_C

  • Trying to get rid of my belly... and failing!
Re: Dynamo lights
« Reply #21 on: 10 November, 2017, 12:51:33 pm »
Nope, the Luxos U is prone to the electronics failing as well, which causes the light to be difficult to switch on or to go flickery. It has some very complex fragile electronics (including a huge 32 bit CPU) and isn't particularly well sealed.

I stand corrected.

I will clarify that I own only Cyo lights. But talking to friends who have had Luxos, they have reported problems with the USB output, which led to them sending them back for replacement. I use a Cyo on my Audax bike with a separate PSU for USB charging.

https://www.kemo-electronic.de/en/House/Home/M172N-Bicycle-Power-Charge-Controller-USB.php

This means I have a less complex bike light. One which has a god reputation for reliability. The USB PSU is a cheap, separate system so if it brakes I can go on using the light. The Kemo is cheap, and although large, sits in a stem pack. It is water resistant, and sits in a water resistant bag. I have had it for nearly 4 years and it has never stopped or required replacing.
@DaveCrampton < wot a twit.
http://veloviewer.com/athlete/421683/

Re: Dynamo lights
« Reply #22 on: 10 November, 2017, 01:27:10 pm »
What does it need a 32-bit CPU for?

It has push-button on-off, push-button high beam mode (if charge is available in the internal batteries) and needs to enabled/disable the USB output based on charge level. I can see why you'd use some sort of microcontroller to do all that, but not such a big one, and the robustness of all that electronics clearly isn't good enough.

Quote
By the way, the Busch + Müller lamps may be poorly sealed in part to promote air cooling. Effective LED cooling, however that is achieved, is critical to good performance.

On the Luxos U the entire top of the light is an aluminium heat sink for the main LED (which is mounted at the top, pointing downwards). I don't think it's putting out enough watts to need more than that.

Kim

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Re: Dynamo lights
« Reply #23 on: 10 November, 2017, 01:51:19 pm »
TBH, I don't think there's going to be anything in it between one microcontroller and another reliability wise, other than those with really small pins being more susceptible to moisture-related faults (which ought to be eliminated by a conformal coating anyway).

The economics of micros are unintuitive, and it probably makes sense to use one chip and software development process for all their products (including those to be designed in the foreseeable future) than to chose something specifically appropriate for each task.  Perhaps they want to build up some real-world experience with a given platform before venturing into ebike controllers or navigation systems or something?

Not to say the Luxos U doesn't have a serious water ingress problem, that's down to mechanical design rather than the complexity of the electronics.  There are plenty of cheap bike lights that demonstrate that simplicity is no protection from waterproofing problems, and plenty of GPS receivers that demonstrate that complex electronics can be waterproofed successfully.

quixoticgeek

  • Mostly Harmless
Re: Dynamo lights
« Reply #24 on: 10 November, 2017, 03:47:23 pm »

Oops, I appear to have just accidentally ordered an SON Edelux II. Should arrive next week.

Thanks everyone for your helpful replies.

J
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