Dynamo lights

[Kim]

Oops, I appear to have just accidentally ordered an SON Edelux II.

    

[Aushiker]

Cyo Premium (80 lux not lumens) - I wouldn't bother with the daytime running light version. Cheap and good, but plastic.

I am curious as to why you wouldn't bother with the daytime running light version.

[Aushiker]

Sort of related to the topic I notice that Supernova now have a GroPro mount available.



Does anyone know if this will work with a Busch & Muller Lumotec IQ Cyo Premium or an Edelux II for that matter? It looks wide enough at the light end from the photo but of course that is not definitive.

The bike I wish to mount the light on, a 2018 Giant Defy Advanced 2 is rather limited in mounting options [no fork mounts, disc brake only, has an interesting hydraulic/mechanical reservoir off the stem] but comes with a GoPro mount specifically for the bike.


Giant Conduct Brake System - GoPro Mount by Andrew Priest (Aushiker), on Flickr

[Kim]

Cyo Premium (80 lux not lumens) - I wouldn't bother with the daytime running light version. Cheap and good, but plastic.

I am curious as to why you wouldn't bother with the daytime running light version.

I've got that version, simply because it was in stock at the time.  It's on my Brompton, so DRL suits how the bike mostly gets used, and it *is* and improvement in off-axis visibility.  (The DRLs also give lots of bonus nearfield spill for pothole dodging, when mounted at Bromtpon fork crown height.)

The disadvantages as I see it are:

A) The non-DRL version uses the light sensor to switch on and off, rather than between modes, making the sensor function more useful.

B) The DRL LEDs are tiny point sources with a horrid blue colour temperature (presumably to get as many lumens/watt as possible), so not particularly pleasant to look at.  (The beam itself is a much warmer white.)

C) The lamp draws more current in DRL mode than in illumination mode (up to the maximum the dynamo will supply at normal speeds), so there's a (barely measurable, certainly not perceptible) increase in drag.


Basically, I'd suggest getting the version that suits whether you're planning to routinely use the light in daylight or not.

[Aushiker]

Basically, I'd suggest getting the version that suits whether you're planning to routinely use the light in daylight or not.

That is my plan and it is likely I will get an IQ-X so it's a given anyway.  That said I was just curious as to the reasoning behind the comment.

[Kim]

The IQ-X's DRL is the upper half of the main beam.  It's a sensible colour, and appears as the entire lens evenly illuminated rather than a tiny point source, so it's much nicer to look at.  Haven't measured the power.

[Samuel D]

I don’t think DRLs are a good idea and also don’t want to waste energy powering lamps when I don’t strictly need them. For I do notice the drag of my Cyo Premium when it’s on, despite using arguably the lowest-drag dynamo hub available (SONdelux in full-size wheel). Maybe that’s because I’m a light cyclist with fast tyres.

Anyway, I wondered if all dynamo lamps cause the same drag. In particular, would the Eyc create less drag than the Cyo Premium? What about the Luxos B? Sounds like something Kim might know!

[quixoticgeek]

Cyo Premium (80 lux not lumens) - I wouldn't bother with the daytime running light version. Cheap and good, but plastic.

I am curious as to why you wouldn't bother with the daytime running light version.

Because maybe during daylight you want the power from the dynamo for something else... like charging batteries.

J

[Aushiker]

Because maybe during daylight you want the power from the dynamo for something else... like charging batteries.

In that case you simply turn off the light. Either way that does not explain why they the person I quoted wouldn't bother with them and to be honest with the exception of Kim's response there hasn't been a credible reason, to me at least, to not go with the option, more so if one's riding conditions at times could benefit from them. 

Both my Luxos lights have them and I cannot notice any issues with them and if charging is more critical I simply turn off the light; I just make that decision based on the riding conditions at the time. To me having the option is better than not having the option. Each to their own of course: I was simply curious as to the reasoning behind the comment. 

Thanks anyway.

[Aushiker]

The IQ-X's DRL is the upper half of the main beam.  It's a sensible colour, and appears as the entire lens evenly illuminated rather than a tiny point source, so it's much nicer to look at.  Haven't measured the power.

That is good to know; thanks. Given the bike that the new light will go will be primarily used for endurance/audax rides I like the DRL option ... that extra bit of visibility sits well with me.

[Kim]

Anyway, I wondered if all dynamo lamps cause the same drag. In particular, would the Eyc create less drag than the Cyo Premium? What about the Luxos B? Sounds like something Kim might know!

Not without doing measurements, I'm afraid.

I've only noticed the current draw of the Cyo T because I was curious about the difference between the daylight and non-daylight modes, and hooking it to a bench power supply and aiming it at a wall made it easy to see the change in controlled conditions.  The Cyo is rated for DC operation, though - The IQ-X manual specifically warns you not to do that, and I've no idea about other models.

If you were going to get scientific about it, step one would be bodging up a truing stand and a power drill to spin a real dynamo wheel.  Even a constant-current AC power supply isn't going to be entirely realistic.

[quixoticgeek]

In that case you simply turn off the light. Either way that does not explain why they the person I quoted wouldn't bother with them and to be honest with the exception of Kim's response there hasn't been a credible reason, to me at least, to not go with the option, more so if one's riding conditions at times could benefit from them.

Mostly this is me confusing this feature with some of the always on lights that don't have a switch. One of the reasons I didn't like the idea of the Supernova E3 pure is that I can't turn it off during the day when I want to charge stuff. For a lot of my rides I don't go near mains power for several days on end, and solar is not reliable enough. So the idea of being able to get 3Wh for every hour of cycling for charging my devices (camera, phone, gps, lights, PLB etc...) rather appeals.

Both my Luxos lights have them and I cannot notice any issues with them and if charging is more critical I simply turn off the light; I just make that decision based on the riding conditions at the time. To me having the option is better than not having the option. Each to their own of course: I was simply curious as to the reasoning behind the comment. 

Thanks anyway.

Misunderstanding on my side.

Apologies

J

[sojournermike]

Cyo Premium (80 lux not lumens) - I wouldn't bother with the daytime running light version. Cheap and good, but plastic.

I am curious as to why you wouldn't bother with the daytime running light version.

Because maybe during daylight you want the power from the dynamo for something else... like charging batteries.

J

This, an I know you can turn it off, but sometimes it's easier to just leave it in sense and leave everything plugged in.

Agree with Kim re IQ-X

[Manotea]

Another vote for the B&M IQ-X 100 lux. I've now got two for around £85-£100 a pop incl postage from German Distributers, the second this summer (GBP=1.10 EUR)

[jsabine]

For I do notice the drag of my Cyo Premium when it’s on,

I am not sure how you would practically conduct a double-blind test of this (well, I've got some ideas), but I'd be interested to see the results ...

My perception is that, over several lights, and several wheels, I don't notice any difference whatsoever.

(I am happy to concede that I am almost certainly slower, fatter and less attuned to my bike than you, but still ...)

[zigzag]

6w is certainly noticeable, most telling test is when one is on an ergo trainer which increases the resistance automatically while pedaling at a constant cadence. when you have ample energy reserves and riding well within your limits 6w are neither here nor there, but at higher intensities (ftp or thereabouts) or when tired extra 6w will feel like a massive drag!
the phenomenon where riders say they don't notice the drag could be due to a simple fact that they drop their cadence slightly and go a bit slower - the effort stays constant therefore it seems that it isn't any harder to ride with the dynamo light on.

[jsabine]

It may well be that (for me) it's reasonably constant effort and no attention paid to speed, so I'm simply unaware - but as I say, I'd be more interested in actual double-blind testing rather than self-reported perception. I suspect that even on an ergo trainer, your perception of effort will be coloured by any numbers you see in front of you.

[Kim]

I've noticed the drag from a dynamo hub exactly once, when freewheeling down a long gentle slope at about 15mph on a still day.  Switching the lights on consistently reduced the speed by about 0.1mph (which is the resolution of the bike computer I was using, so there's a fairly wide margin of error).  Changing my hand position from the flats to the bar-ends (flat-barred bike) make a much bigger difference.

What's more noticeable is vibration from the dynamo (if it's a particularly buzzy dynamo - most aren't) when it hits a resonance frequency, but I don't believe that translates into a significant loss of power.


Zigzag's point is interesting.  As ever with cycling, real-world conditions are dominated by the effects of weather and psychology, so it's hard to draw meaningful conclusions.

[Aushiker]

Mostly this is me confusing this feature with some of the always on lights that don't have a switch. One of the reasons I didn't like the idea of the Supernova E3 pure is that I can't turn it off during the day when I want to charge stuff.

I noticed that about the Pure and dropped it off my short list. I have pretty much decided to stick with Busch & Muller and will go with an IQ-X I think. Too much hassle with Supernova and having to use their rear lights [I have a couple of spare Secula's which I can mount on the seat stays].

Interesting discussion anyway about the DRL.

[Aushiker]

Another vote for the B&M IQ-X 100 lux. I've now got two for around £85-£100 a pop incl postage from German Distributers, the second this summer (GBP=1.10 EUR)

Good to know. I can get one from http://bike24.com for EUR 67.14. Sometimes there is an advantage to living down under

[Butterfly]

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.

And even then, I have cyos on several bikes, including one fork mounted with no mud guards and one on the hoop of a low rack and I've never had one fail. I comuted for several years in all weathers with no issues.

[Samuel D]

It’s hard to separate the feeling of extra work from the increase in vibration/noise and knowledge of the drag that must be there when the lights are on. But I am confident I notice it on familiar roads in two cases: (1) when just rolling along at low speed, and (2) when pushing hard, like zigzag on his trainer.

Regarding case (1), my bicycle, like any with good tyres and efficient transmission, wafts along with unbelievably low effort below 20 km/h. With the lights on, that feeling changes slightly, a bit like the change caused by fitting a slower tyre.

It is interesting that Peter White warns about an incompatibility between the IQ-X and the USB-Werk (find “werk” on that page). I wonder if that implies that the IQ-X uses a different (more power-consuming?) driver.

Butterfly: nice to hear that the Cyo doesn’t necessarily die if exposed to water from below.

[Kim]

It is interesting that Peter White warns about an incompatibility between the IQ-X and the USB-Werk (find “werk” on that page). I wonder if that implies that the IQ-X uses a different (more power-consuming?) driver.

The IQ-X is noticeably more flickery than a Cyo at very low (ie. about to stop, rather than climbing hill) speeds.  I assume because it draws more power.

[Samuel D]

I see. By the way, why do they flicker at all? With my negligible understanding of electronics, it seems like you could just add a bigger capacitor. It’s odd that when slowing to a stop the lamp works better when stopped than very slow.

[Kim]

I see. By the way, why do they flicker at all? With my negligible understanding of electronics, it seems like you could just add a bigger capacitor.

You could, but it's a tradeoff with cost, weight and physical volume.  As long as it gives a smooth light at the lowest realistic steady bicycle speed, it's probably good enough for most purposes.

It's probably reasonable to assume that most cyclists who are interested in high performance lights don't spend much time riding at 3mph.  I'd certainly have given it a bit more smoothing, but I'm used to thinking tricycle.