Author Topic: Repeatedly faulty B&M light  (Read 1472 times)

fd3

Repeatedly faulty B&M light
« on: November 16, 2019, 12:12:44 pm »
I bought an IQX from Rose which stopped working entirely after three weeks' use.  The replacement is also faulty (it doesn't hold charge, won't switch on half the time and will change to daylight mode in the middle of a dark unlit cycle path in the middle of the night).
I am considering asking for an 80lux Cyo instead of a third replacement IQX, but I am not sure that I can trust B&M's QC if they manage to serve me up two lemons.  What is everyone else's recent experience?
[/I could be wrong]

Re: Repeatedly faulty B&M light
« Reply #1 on: November 16, 2019, 12:27:08 pm »
Persist with the IQ-X until you get one that isnt faulty.

Mine has been rock solid for several years and it is great.

Kim

  • Timelord
Re: Repeatedly faulty B&M light
« Reply #2 on: November 16, 2019, 12:33:09 pm »
I've got two which are now about 3 years old, one of which is a replacement for one which had the not-switching-on-unless-in-motion fault.  As I operate them from an inline switch, I can't vouch for their continued correct switch behaviour, but since they seem to be doing the producing light (and switching betwen night/day mode) things properly, I'm not particularly bothered.

There does seem to be a serious quality control issue.

I'm happy with the Cyo Premium on my Brompton, but the extra width of the IQ-X beam is invaluable on a recumbent.  I found myself riding on an unlit cyclepath by the light of the Cyo-R on my hybrid recently, and was distinctly underwhelmed (it normally gets used on urban roads with streetlighting).
Careful, Kim. Your sarcasm's showing...

fd3

Re: Repeatedly faulty B&M light
« Reply #3 on: November 18, 2019, 11:41:53 pm »
Worked today, wonder whether it can magically fix itself?  It appears to switch itself on when I start moving, is this normal?
[/I could be wrong]

Kim

  • Timelord
Re: Repeatedly faulty B&M light
« Reply #4 on: November 19, 2019, 12:06:21 am »
It appears to switch itself on when I start moving, is this normal?

It is if it was switched on when you stopped moving...


IIRC Cudzoziemiec has one that likes to switch itself on at random.
Careful, Kim. Your sarcasm's showing...

Re: Repeatedly faulty B&M light
« Reply #5 on: November 19, 2019, 07:41:03 am »
Worked today, wonder whether it can magically fix itself?  It appears to switch itself on when I start moving, is this normal?

Bumm considers this a safety feature. I consider this a fault.

JonB

  • Granny Ring ... Yes Please!
Re: Repeatedly faulty B&M light
« Reply #6 on: November 19, 2019, 08:34:12 am »
I've got two which are now about 3 years old, one of which is a replacement for one which had the not-switching-on-unless-in-motion fault.  As I operate them from an inline switch, I can't vouch for their continued correct switch behaviour, but since they seem to be doing the producing light (and switching betwen night/day mode) things properly, I'm not particularly bothered.
I think mine has that fault, have to spin the wheel and then hit the switch to get it on or just push it when I start to move. It will hold the standlight and turn off when stopped but won't switch on again until on the move.  It's a good light and works ok in other respects which is why I've not bothered to return it, I've got Cyo premium's on other bikes which work as they are supposed to - these are great value for money and functional.

Re: Repeatedly faulty B&M light
« Reply #7 on: November 19, 2019, 11:57:07 pm »
The reason you can't switch it on is because the switch needs to have POWER to operate & seeing as it's a DYNAMO light guess where that comes from when the capacitors are dead?

Yep! you guessed it The DYNAMO which only produces POWER when the wheel rotates.

So you have to be moving before you can switch on the light.

NOT a very clever design, but apart from recalling all the IQ-X's and redesigning with a physical switch, there wasn't much they could do.

So they declared it to be a design feature. :facepalm:

I refuse to call it a "Safety" feature because it's daft.

It does light up the road nicely though on my ICE Qnt. :smug: And YES, mine does have the "fault".

Kim

  • Timelord
Re: Repeatedly faulty B&M light
« Reply #8 on: November 20, 2019, 12:24:17 am »
The reason you can't switch it on is because the switch needs to have POWER to operate & seeing as it's a DYNAMO light guess where that comes from when the capacitors are dead?

The fault isn't that it can't bootstrap from a fully discharged state, it's that they aren't using stored charge to maintain the switch functionality for a reasonable period (at least several days) after switch off.  I've no idea if that's due to the capacitor discharging faster than anticipated (leakage?  unexpectedly high quiescent current?) or because it's failing to reserve sufficient stored charge to preserve the switch operation (standlight failing to switch off at some voltage threshold?  assumptive time-based switchoff?), but it's clearly a fault.

Evidence:  Having owned two IQ-Xes that are (or at least were when new) able to switch back on after being switched off and the bike stopped for several days, and an email from B&M saying that this behaviour is a fault, and that I should return the light to the retailer for a replacement.


On that basis, I suspect it's a quality control of components issue, rather than a fundamental design flaw.  Which isn't to say that a hard switch wouldn't neatly avoid the problem (while introducing the usual mechanical ones).  My guess is that they've been caught out by a batch of capacitors not performing long-term like they did in the lab, and hand-waved the issue to avoid a recall.
Careful, Kim. Your sarcasm's showing...

Re: Repeatedly faulty B&M light
« Reply #9 on: November 20, 2019, 06:54:27 pm »
I have fitted a Cyo premium senso plus light to my recumbent today. It has a switch for off, senso, on ,  daylight running LEDs, stand light and 80 lux. Comes on tonight as soon as you spin the wheel if in senso or on mode. Seems remarkably good value as well compared to the Luxos and iq-X lights.

Kim

  • Timelord
Re: Repeatedly faulty B&M light
« Reply #10 on: November 20, 2019, 07:16:38 pm »
I reckon those are the sweet spot for bang-per-buck, and they're a proven design.  The IQ-X beam is wider (and slightly brighter), though.
Careful, Kim. Your sarcasm's showing...

fd3

Re: Repeatedly faulty B&M light
« Reply #11 on: November 20, 2019, 11:46:37 pm »
I wonder whether the low light could be due to low capacitor charging - but then I would expect that if I pedal over 10mph that should power the light without needing to cycle for a couple minutes with the light off.

I am rather stuck as the light has now functioned for the last three days with no issues.  On the other hand it did fail epicly and the previous model (that I sent back) did so too (but that time 7 miles from hoke on low lit roads).
[/I could be wrong]

Re: Repeatedly faulty B&M light
« Reply #12 on: November 24, 2019, 04:09:47 pm »
You can turn the light on when stopped if there is residual charge in the capacitor.  This lasts for a while but will probably leak away overnight.  In contrast, the Cyo capacitor holds charge for weeks and weeks.
Never tell me the odds.

fd3

Re: Repeatedly faulty B&M light
« Reply #13 on: November 25, 2019, 09:55:26 pm »
Well, it went off while riding in the dark again tonight ... twice (both times at speed).

F- it, I'll ask for a swap to a Cyo Premium.
[/I could be wrong]

Re: Repeatedly faulty B&M light
« Reply #14 on: November 25, 2019, 11:25:11 pm »
FWIW I don't feel a burning need to have a standlight, auto-on off, daytime running lights, or any similar gimcrackery in a dynamo front light. Unfortunately most of the brighter B&M lights (like the IQ-X) come with these things whether you like it or not, and (to my mind) this is bound to decrease reliability.   I'd far sooner have the nice housing with just a reliable light (and good optics) within it.

I have recently made an observation about cheap dynamo lights which may be of interest.

In days past, if you wanted more light at speed you could run two 6V lights in series and you would (given a few givens) get about twice the light at speed when using many different generators. However this did come with less light at low speeds. This approach still works with LED lights.

The alternative approach was to use two lights in parallel; however this usually does not result in more light because the current is simply shared between two lights. If LED lights are used, and all the current is passed through the LEDs, pretty much the same thing is true (give or take a bit of efficiency variation with current, which is slight).

However cheap-ish LED type dynamo lights are (usually) designed to use 2.4W @6V (so as to comply with StVZO standards) but do not pass all 0.4A through the LEDs.  The LED devices used may have a rating of 1W or less, which means that the current going through them (when warm especially)  may only be 0.2A or so; the rest is just wasted. Note also that such lamps are often capable of reaching full brightness at low speed, often when the generator is only producing about 5V or so.

I also note that quite a few hub generators will happily produce a bit more than 0.5A when driving loads which draw current at about 5V or so.  This varies a bit but 0.6 or 0.7A is often on the cards. It is also possible to get a rear light that only needs about 30mA or so, which leaves a bit more for the front light(s) too.

The net effect of all this is that if you attach several such LED lights in parallel (I have tried up to three) then you do seem to get more light. [ I also plan to try four lamps in two pairs, both series and parallel. ]

So one scheme is to run the lights as 'normal' most of the time, i.e. with a standard rear light and just one front light, when conditions are mostly such that a 'be seen' light would be adequate. Then, should more light be required (e.g. on an extra-urban night-time ride) then a pair of extra front lights can easily be added (eg on a QD handlebar mount of some kind) and connected by  simply by piggybacking on the rear light terminals.

An attraction of this scheme is that your eggs are not expensive eggs and they are not in one basket either; any one lamp could fail and it wouldn't be the end of the world.   I don't know how the end result compares (in terms of overall light output) with just one bright light, but I suspect it may not be that far off.   

cheers

Cudzoziemiec

  • Dormant but requires tea
Re: Repeatedly faulty B&M light
« Reply #15 on: November 26, 2019, 08:49:56 am »
It appears to switch itself on when I start moving, is this normal?

It is if it was switched on when you stopped moving...


IIRC Cudzoziemiec has one that likes to switch itself on at random.
I do. Nowadays I never turn it off because there's no point and because there's a slim chance of its suddenly turning itself on being misread as an invitation to proceed (like flashing headlights). Fortunately it's never turned itself off.

Both that and the other one have the won't turn on unless moving fault, which I'd be inclined to say is a faulty capacitor; if you turn it off while the standlight's going then immediately on again, it works, so my deduction is the capacitor isn't storing whatever it needs for initial illumination. But please don't trust my electrical "knowledge". I've taken a similar attitude to JonB on this.
The unwilling rider and the one who leaves each control in turn without reluctance, with no desire to come back, obviously cannot be making the same journey, even though their brevets are identical.

fd3

Re: Repeatedly faulty B&M light
« Reply #16 on: November 26, 2019, 11:18:28 pm »
FWIW I don't feel a burning need to have a standlight, auto-on off, daytime running lights, or any similar gimcrackery in a dynamo front light. Unfortunately most of the brighter B&M lights (like the IQ-X) come with these things whether you like it or not, and (to my mind) this is bound to decrease reliability.   I'd far sooner have the nice housing with just a reliable light (and good optics) within it.

The net effect of all this is that if you attach several such LED lights in parallel (I have tried up to three) then you do seem to get more light. [ I also plan to try four lamps in two pairs, both series and parallel. ]
I mostly agree with the first paragraph, though I would like a standlight.
I thought that a luminosity-or-is-it-lux-log-thing meant that two identical lights only give 10% more light (or summat).
[/I could be wrong]

Kim

  • Timelord
Re: Repeatedly faulty B&M light
« Reply #17 on: November 26, 2019, 11:47:18 pm »
I thought that a luminosity-or-is-it-lux-log-thing meant that two identical lights only give 10% more light (or summat).

The eye's response probably factors in there?  Certainly adding a second identical light source doesn't result in all that much perceived difference.  The main advantage of having two lamps is that you can point them in different directions, though that's an advantage that's been steadily decreasing as beams have got wider...
Careful, Kim. Your sarcasm's showing...

Re: Repeatedly faulty B&M light
« Reply #18 on: November 27, 2019, 12:39:57 am »
I think the eye is differently sensitive in a kind of logarithmic way, so if you want something to subjectively appear to be 'about twice as bright' you need ~x10 the instrumented brightness.

BTW I have tried a few more experiments and it turns out that the cheapo lights I am using get pretty bright when the measured AC voltage (on my DMM) is only about 3.5V. I have not checked it with a 'scope yet but I expect the voltage waveform to be pretty much flat topped. 

This means that running such lights in series does not result in much loss of brightness at low speeds; most generators produce ~7VAC (peak) at quite low speeds and as soon as they do there is some light rather than none.

The shimano hub generator I am using will power four of the cheap lights (to a good brightness, possibly not full) even with all four in parallel. With the four in pairs, parallel and series, there is 'really quite a lot of light'.  However it is going to be a bit OTT to have four separate lights on the front of the bike!

cheers

Cudzoziemiec

  • Dormant but requires tea
Re: Repeatedly faulty B&M light
« Reply #19 on: November 27, 2019, 09:11:07 am »
FWIW I don't feel a burning need to have a standlight, auto-on off, daytime running lights, or any similar gimcrackery in a dynamo front light. Unfortunately most of the brighter B&M lights (like the IQ-X) come with these things whether you like it or not, and (to my mind) this is bound to decrease reliability.   I'd far sooner have the nice housing with just a reliable light (and good optics) within it.

The net effect of all this is that if you attach several such LED lights in parallel (I have tried up to three) then you do seem to get more light. [ I also plan to try four lamps in two pairs, both series and parallel. ]
I mostly agree with the first paragraph, though I would like a standlight.
I can't see the point of not having a standlight. It adds the very useful, reassuring function of being seen when stationary at junctions or just stopped at the side of the road for a banananana or whatever, as well as a little light for searching in saddlebag etc. But the fact that we have the word standlight at all says something about attitudes; it's just German for parking light or side light, or to use the modern terminology position light (Standlicht).
The unwilling rider and the one who leaves each control in turn without reluctance, with no desire to come back, obviously cannot be making the same journey, even though their brevets are identical.

Carlosfandango

  • Yours fragrantly.
Re: Repeatedly faulty B&M light
« Reply #20 on: November 27, 2019, 10:42:38 am »
They're great when they're working, but.....

I've got an old B+M Luxos, it's been good, but then one of the tangs to connect the rear light broke off, it's corroded. I contacted B+M and they sent me some new tangs and I've managed to solder the new one in place.

However, the components are densely packed inside the casing and not positively located, so getting the light back together with everything in the correct position is very, very difficult. I haven't achieved it yet.

Deep breath, calm, try again.

Re: Repeatedly faulty B&M light
« Reply #21 on: November 27, 2019, 10:53:55 am »
The most likely point of failure on a dynamo setup is the external wiring, followed by the headlight bracket. Worrying about the complexity of the electronics inside the box* is madness, especially something as simple as a standlight.

(* unless it's a Luxos U, because they're shite)

Re: Repeatedly faulty B&M light
« Reply #22 on: November 27, 2019, 11:45:43 am »
I can't see the point of not having a standlight. It adds the very useful, reassuring function of being seen when stationary at junctions or just stopped at the side of the road for a banananana or whatever, as well as a little light for searching in saddlebag etc. But the fact that we have the word standlight at all says something about attitudes; it's just German for parking light or side light, or to use the modern terminology position light (Standlicht).

you are not legally required to show any lights when the bike is stationary. The advice is that you shouldn't be out in the road, stopped, e.g. when  making a right turn if you are running dynamo lights but that is all.


In terms of 'not being seen' when stationary and therefore being run into, I don't think you have much to worry about there, not unless you go out of your way to dress bike and self like a stealth ninja. Modern cycle kit is liberally decorated with reflexite and the biggest risk of anyone running into you is because folk don't always look where they are going; you could be lit up 'like a ****ing Christmas tree' and it wouldn't make the slightest difference.

There is a small risk if you pull across an unlit junction from a standstill; you might not have been seen by (say) a car turning right across your path.   Here a front reflector is useful (a legal requirement in Germany and other places) and I usually run with a few spoke reflectors on the front wheel too; they show up very well and when there are only a few of them it often causes most other road users to do a double take which is no bad thing.

But for the most part a front standlight is a palliative for the mind rather than a practical help with being seen by other road users.


The downside to the standlight is that it is a device which is inherently prone to failure; 'supercapacitors' are not, er, that super in fact.  If the light is well designed, it still works as normal when the standlight takes a dump. However not all lights are like that and it often causes other problems. 

If you wish to avoid problems with corroded wiring and brackets breaking etc, just corrosion proof the wires properly and don't use shite brackets. A well-set-up system ought to be free of that kind of fault for decades, even if it sees all the weather.

cheers

Re: Repeatedly faulty B&M light
« Reply #23 on: November 27, 2019, 11:57:42 am »
I was thinking of:
- Wire headlight brackets snapping at the base where the sharp bend is.
- Plastic headlight shells snap around where the bracket lugs stick out.
- Wires break (or more likely the connectors) when they get snagged on things, or short where cable ties wear through the insulation, etc.
- Ripping the plug off when you get a front puncture while tired.

None of these are avoidable with corrosion proofing.

Cudzoziemiec

  • Dormant but requires tea
Re: Repeatedly faulty B&M light
« Reply #24 on: November 27, 2019, 12:31:49 pm »
I can't see the point of not having a standlight. It adds the very useful, reassuring function of being seen when stationary at junctions or just stopped at the side of the road for a banananana or whatever, as well as a little light for searching in saddlebag etc. But the fact that we have the word standlight at all says something about attitudes; it's just German for parking light or side light, or to use the modern terminology position light (Standlicht).

you are not legally required to show any lights when the bike is stationary. The advice is that you shouldn't be out in the road, stopped, e.g. when  making a right turn if you are running dynamo lights but that is all.
Legally if you have a dynamo without standlight, you're supposed to only stop on the left, which makes right turns a bit difficult. I don't suppose anybody actually paid any attention to that rule even back in the pre-standlight days. But legality isn't my concern, it's that we're no longer in the pre-standlight days. You'd nowadays have to deliberately search for dynamo lighting without standlight. Why would you do that rather than choose one of the many easily available, brilliant (pun intended) and efficient dynamo systems with standlight?
The unwilling rider and the one who leaves each control in turn without reluctance, with no desire to come back, obviously cannot be making the same journey, even though their brevets are identical.