Cycling UK Forum

On ebay I stumbled across some old adverts for British dynamo lamp companies:

so why did the UK settle on battery lamps?

and, why not at least, settle on hybrid systems like the SA dynohub with its filter unit (a bridge rectifier with battery fill in via a diode); that would at least save some battery cost and leave lights available when moving even if battery was flat?

CJ wrote:I am even more sorry that the work I put into the old website (that provided most of most-viewed pages on that site), was not transferred

Could you get the website authors to extract your old technical pages from their "code source history", rea-add to new website, and place a link within the new website to it:

the simpler layout wouldn't matter to most and probably loads faster.

Alternately, the wayback machine will have archived the old website at various dates, e.g.:
http://web.archive.org/web/20120106202607/http://www.ctc.org.uk/DesktopDefault.aspx?TabID=3331

Also, is the extra info on hub dynamos available?

It would be better if it was just a 6V generator allowing use of normal LED dynamo lamps.

I always thought It would be nice if a "hub" dynamo did'nt need a wheel build but just attached to the side of the hub (eg to a disc mount); a front hub could then have double disc mounts, one of which could be either be used for a dynamo or for twin front brakes on a tandem (and avoid dishing)----

a gernerator only version using either the rim or a disc rotor would have the same effect.

If people are too nervous to brake from the speed they were doing on main beam to an appropriate speed for dipped headlamps
then maybe there should be a night time speed limit for non motorway roads:

it seems the maximum range of dipped headlamps doesn't quite allow 40mph using highway code braking distances, so

max 45mph / 50mph at night?

EDIT: I think the difference between 50 and dipped is too big: 40 limit?

I was asking about the situation where the front driver has to use dipped headlamps due to oncoming traffic, or to switch to dipped headlights early e.g due to an oncoming corner, especially on twisty roads, where this will happen a lot:

in these cases the range of the dipped headlamps should cause them to slow(limit) their speed, but most people just seem to blindly follow the dotted lines/catseyes as fast as they like.

(I know the IAM response to tailgating is to essentially place the trailing drivers missing gap in front of you by doubling your gap, but I don't drive anymore so having to do an IAM test just to get an argument listened to seems rather extreme )


(NB I wasn't asking about the situation of motor vehicles deliberately "blocking" a person behind from overtaking, just the one where they drive faster than they should (can see) because of what the driver behind might possibly do)

Sometimes when suggesting correct driving, like driving within the range of your dipped headlamps, I get an annoying response along the lines
"yes, but if I slow down to suit the range of my dipped headlamps then any following driver will just overtake me".: (implied so there's no point in driving properly)"

Are there any good responses to this other than pointing out that the driver(s) behind are responsible for their own driving and won't go to court for you if you hit someone because of the above idea.

CJ wrote:

ISO are working on a new international standard and I did try to steer it in the direction of simple performance requirements, that the better 'non conformist' manufacturers might possibly like to conform to. But that was scuppered by a Franco-German alliance.....(...German traffic law, which this ISO is an enhanced copy of)

Are the Germans/French speculatively derailing that standard just for an unlikely economic benefit to themselves?
if there is little chance of the derailed ISO being used by even themselves, isn't that rather inconsiderate?

EDIT I think it is so that the French can indirectly use the German standards because directly requiring German standards would presumably be politically unpalatable. I suppose the UK could adopt it too.

The "warmer" phosphor converts the unwanted excess blue light into extra desirable colours, a filter just gets rid of some colours: hence I want a warmer phosphor, I have no interest in the excess blue light of a cold white LED, filtering it away would simply cost me some good colours, so I would rather have a neutral or warm white LED.


It seems the B&M Luxos is still a cold white LED: Bahhhh.

CJ wrote:

ISO are working on a new international standard and I did try to steer it in the direction of simple performance requirements, that the better 'non conformist' manufacturers might possibly like to conform to. But that was scuppered by a Franco-German alliance.....(...German traffic law, which this ISO is an enhanced copy of)

As the Germans/French presumably hope/think someone will use the ISO (and thus create a market), but the ISO seems unattractive to other countries/manufacturers, does that mean perhaps one of themselves intends to use it?

However, would an ISO standard not then be slower to react to new technology (like LEDS) than the German approval body, which would be a large disadvantage; also, the German standard seems a bit behind even for LED front lamps, both electrically and optically:

electrically I think it makes more sense to have the rear lamp fed from the output of the front lamps power convertor as the voltage /current waveform of the dynamo can then be left to take (be distorted into) whatever form suits that power circuitry (for best efficiency/max power extraction) with that then supplying the expected 6V 0.1A to the rear lamp. E.g the dynamo could be used at a higher voltage--lower current into step-down convertor (s). for less resistive losses.

optically:
the guy at http://swhs.home.xs4all.nl/fiets/tests/ ... ex_en.html seems to think the Stvzo does not make it clear/easy how to mount a lamp to be properly dipped (eg the Trelock 885 review http://swhs.home.xs4all.nl/fiets/tests/verlichting/koplampen/Trelock_ls885/index_en.html mentions that it seems a bit easy to set as undipped but has a nicer beam colour/temperature than most )

He seems to suffer from low cycle paths (below road level) that place the cyclists eyes at adjoining car headlamp level : this seems rather blindingly non-Utopian. I wonder why have the cyclists have not demanded the paths be raised, given that they can't use the adjacent road.

Brucey wrote:....use of yellow glasses with LED lamps....

But yellow glasses will just remove the blue light, they won't replace it with warmer colours (which is what I want from the warmer LED phosphor). They might be useful from reducing glare from car headlamps with excess blue (eg HID lamps and their halogen imitators).

Apparently the Trelock 885 is slightly warmer than usual:
http://swhs.home.xs4all.nl/fiets/tests/verlichting/koplampen/Trelock_ls885/index_en.html

robc02 wrote:I am guessing that the reason, or part of it, is that bike light manufacturers want to quote the highest number of Lumens for their products - indeed they are pressured to do so by reviewers and parts of the buying public. Using warm white LEDs would lower the figure, albeit slightly.

But dynamo lamp manufacturers seem to quote lux values (inspired by the German market presumably) and the lux value will also be dependant on the area of the beams bright patch as well of the amount of lumens from LED:

so they could keep marketing happy by keeping the lux value the same but very slightly reducing the beam area to compensate for the small (10%) cost of a warm white LED. I suspect the shrinkage wouldn't be very noticable.

(Or they could try and find some (mythical?) marketing persons who can explain stuff rather than just quote bigger numbers, )

stewartpratt wrote:...I think the OP is asking about warm LEDs, which are basically normal ('blue') LEDs with phosphor added. This acts as a filter, basically clipping the shorter-wavelength output and changing the colour temperature accordingly.
...
So as far as I can see, on wet roads, a warm LED isn't going to give you back any more light than a standard LED....

No, warm LEDs have more and/or possibly different phosphor (to colder white LEDs) so that more blue light * is converted to other colours (the phosphor is not a filter: its more like a convertor). The thicker / different phosphor of a warm white LED incurs a small cost in lumens per watt, but I (the OP) am arguing that that is of less significance if a reasonable proportion of those extra lumens consists of the colour (blue) of which no more is desired (because the warmer colours are better in the rain).

*white LEDs are really blue LEDs covered in phosphor to convert some of the blue light to other colours.

Given that warm white LEDs only seem to drop about 10% in output (compared to cold/neutral) white and as colder LEDs simply output more blue light than is needed, (making the comparison slightly unfair: the colder LEDs should have their lumens reduced by the amount of "excess" unwanted blue light for an application):

why are there no warm white LED dynamo lamps?
Surely more consistent performance in the rain, is better than approx 10% better performance in the dry?

Are there any neutral white lamps (even the Philips saferide is crystal white: somewhere between cold and neutral)?

A compromise is to only fit the 'plus' style tyre to the rear and fit what you consider a better riding tyre to the front, where punctures are quicker to fix / less likely.

Having found my old Ever Ready 2 D-cell front and back lights I put a white .... LED in - much brighter and ...... The front beam spread is great even with naff bricklike retro styling!

This would suggest that for replacement white LED 'bulbs' (like those of reflectalite.com), the best host lamp is one with a narrow beam such as old battery lamps or maybe SA dynohub lamps. The large emitter size of the LED will then make the less focused beam wider, like a dynamo.