I'm trying to determine the relative suitability of LED, Xenon,
halogen and krypton bulbs for use in cycle headlights for use on unlit
roads. I hear people say that LEDs are the most efficient, but I also
hear people say that it's difficult to focus them into a long enough
beam for use on dark roads. I hear people say that Halogen lamps are
more suitable because they give longer beams, but are not as
efficient. I hear people say that krypton bulbs are better, and I hear
people say that xenon bulbs are better still. Anyone agree?

What I want, personally,  is a front light that is *inexpensive* and
will give a long and sufficiently wide, bright beam for 2-3 hours on 2
or 4 rechargeable NimH 'AA' batteries - and isn't likely to blow its
bulbs. Is that feasable? Which of the above bulb types is most likely
to be in such a lamp?

Thanks...

Jim D

Hmm, not quite inexpensive at 40 quid, but the Cateye EL530 is getting
some very good words.

-Alex

I have two now, scorchingly bright.  Oh, you can get them from the US
on eBay for around £25-£27 delivered, try geargurl and zbikenut.

Yes, but not by much at the moment (the technology is improving rapidly
though).

This might have been true for a cluster of 5mm LEDs, but it's doesn't apply
to the high-power (i.e. >= 1W) LEDs that are now available.

Not really. I think you'll find different manufacturers using various terms
to claim that their bulbs are better than others, I wouldn't take much
notice.

If you're worried about blowing bulbs, just go with LEDs. These are now
available for both battery and dynamo powered systems, but if you really
want inexpensive you're pretty much limited to battery powered. There have
been lots of discussions about lights recently (it's that time of year),
you can use Google Groups to search the archives. I'll just say I like my
Trelock LS-600, and were I not able to get another one of those I'd go for
a B&M Ixon, but YMMV depending on what your priorities are.

Anthony

On Wed, 01 Nov 2006 13:28:14 +0000, Anthony Jones

Thanks for the informative reply. Yes, there's a lot to be said for a
(LED) bulb that won't blow at an inconvenient moment.

Jim D

That's nowhere near enough battery power to run a halogen or any filament
bulb sufficiently bright for so long.  You'll have to either spend a lot of
money on a new-generation LED light or change your mind about the battery
size (if not getting a dynamo) and use halogen lamps.  Why not use a
separate battery strapped under your top tube or in a bottle cage?

~PB

Bulb blowing is no big deal if the bulb is easy to change* and you have a
backup LED light.  Don't let this factor put you off halogens.  MR11 halogen
bulbs, for example, even when over-volted, actually last ages anyway.

* eg. with Lumicycle lamps, the front ring unscrews and the bulb plugs into
the holder.  All done in a few seconds without removing the light from the
bike.

~PB

Jim D said the following on 01/11/2006 15:08:

Does this mean you have a problem with blowing bulbs, or just that you
would rather avoid the risk?

FWIW, I bought my current lighting set-up nearly 10 years ago, and
bought a spare halogen bulb at the same time.  I haven't used the spare
yet!  The bike is used for daily commuting, and that means lights in
both directions very shortly.  Mostly been driven off a bottle dynamo,
but changed to a dynohub a couple of years ago.

However, I bought a cheap LED set from Halfords at the weekend to make
my MTB legal (more or less), and I was stunned at the LED brightness.
If Withington Cycles don't hurry up and deliver my B&M light to replace
the one I broke (bulb still OK though!!), the order will be cancelled
and I'll get an LED front light instead.

The Halfords one, if anyone is interested, is on wiggle as "Smart
Polaris II Super White 5 LED Front Light" at £20.

--
Paul Boyd
http://www.paul-boyd.co.uk/

That Polaris light is great for being seen by and as an emergency backup to
see by, but not good enough for routine use for more than a few minutes on
unlit roads, IMO.  That is if you like to /comfortably/ see where you're
going and to see well ahead.

I'm guessing you'd agree, Paul, but I just wanted to clarify.

~PB

Pete Biggs said the following on 01/11/2006 15:40:

I dunno - it's pretty bright.  I haven't used it for unlit roads though,
or unlit off-roads for that matter, but that wasn't the intention.
There is only one bit of my commute (where I also use this light as a
backup to my halogen light) that doesn't have streetlights and is a bit
dark, but there's so much light pollution that it isn't really an issue.
  These lights were really bought to take with me on my MTB in case I
get caught out so that I was at least showing willing!  If I'd planned
to cycle off-road at night (which is actually great fun, but  my local
woods is probably full of doggers and druggies at night!) I would
probably get something like the EL530.

--
Paul Boyd
http://www.paul-boyd.co.uk/

It's not fair (stamps foot)

Following up to my "SON dynamo, bulbs keep blowing" post. The bulb I
put in on 16th October failed on 27th October.

So I managed something of the order of 7 hours with that bulb :-(

I'm now using a Cateye Opticube. I may not get time this weekend but
I'm going to see about putting in a rectifier and running it off the
dynamo instead and see what happens.

(I've already done a few tests and it draws 240mA @ 5.97V so hopefully
a 22R 3W wirewound resistor in parallel with the light will be all that
is required. - will up the resistor if the light is too dim)

Just have to hope that the rear light doesn't mind being driven from
DC.

(The brompton can't fold with the light on the handlebars and removing
it won't be an option when it's wired into the dynamo but I'll work
something out)

Tim.

[Polaris 5-LED light]

Not compared to a 5W MR11 halogen, nor is the beam pattern as smooth.

Maybe two of them together would be quite reasonable, however -- perhaps
producing a more pleasing result than some more powerful single lights.

I'm just concerned about not raising people's expectations too much.

~PB

On Wed, 1 Nov 2006 15:06:50 -0000, "Pete Biggs"

I see... Thanks for clarifying.

Could do. It's just that I have a charger that charges 4x NimH AA
batteries (and 4x nIMH batteries) and was hoping to put it to good
use!  I never seem to be riding for more than 2-3 hours at night.

Perhaps a new-generation LED that runs on 4 AA batteries would be the
way to go.

I was hoping to find one that had one main-beam LED and an additional
smaller LED for use on lit streets to save power - but I've only seen
them with 'on' and 'off' options.

Still, the amount of time saved, fiddling around with battery
chargers, might justify the extra cost.

Jim D

On Wed, 1 Nov 2006 15:13:59 -0000, "Pete Biggs"

Yes, I expect you are right. I was probably thinking of the older
style non-halogen bulbs. Can you suggest a minimum wattage for totally
dark, unlit roads? I guess 1.2w is pretty useless, is it?

Jim D

You could get a battery box that takes 6*, 10 or 12* ordinary NiMH AA cells.
Doing two or three lots of charging is a bit of a nuisance but doesn't take
long with a fast charger.  Actually I do this myself sometimes to save using
my expensive battery so often (they don't last forever).

Small neat MR11 halogen lamps are available separately from Lumicycle for
about £30 or you could make your own.  This larger MR16 homemade one here on
eBay is great, though I'm not sure you'd get enough run time with a 20W
bulb: http://tinyurl.com/y9mbhk.  (MR16s under 20W tend to have very poor
beam angles & patterns in practice)

* Use with 6 or 12V bulbs respectively.  The over-volting dramatically
increases brightness, whiteness and efficiency, albeit at the cost of
reduced bulb life.  Two 6-cell battery boxes can be wired together in series
if you like.  Wrap in a plastic bag and it makes quite a neat package to
vecro-strap to the bike.

~PB

Take a look at Busch and Muller Ixon. Not cheap, but very good for LED
portable solution. Runtime fis with your need, and It's OK on it's own on
the unlit section of my route.

Just over £50 imported from Germany (several sellers on Ebay) Including
batteries and charger. This is also good because it charges the batteries
inside the lamp, without removal.

Jc.

5W minimum for halogen, is my suggestion.

It's possible to see where you're going with less than that -- but not if
you want to feel relaxed *or* want to go fast safely.  You have to
concentrate much harder than usual and also brake down the hills.

Another point regarding run time & battery capacity:  If /any/ of your ride
is on lit roads, it's well worth using just a small LED light for the lit
bits and saving your main system for the unlit bits.

~PB

Oooh, are you local? <waves>

A very well stocked website, with a not very well stocked shop behind it.  
Nice chaps there thobut - happy to fix bikes instead of just sell 'em,
unlike the one up the road (obviously making too much money to bother with
the dirty stuff).

Streuth, thats 50 euros over here.  I'm in the wrong business, I should
be shipping those things back.

On 1 Nov 2006 04:49:44 -0800, "Alex" <a...@greenbank.org> wrote:

Any idea how it compares to the B&M Ixon?

When I wrote the above I was thinking more about MR11-based systems and
forgetting about the large 3W halogen light I used to use with a dynamo.
That was quite useful on unlit roads.   So it depends on the type and size
of the lamp and bulb as well as the wattage (and the amount of
over-volting).

~PB

Which is why I bought one from Germany, but add the batteries and charger
and shipping gets you to about £50.

Buy one from a UK dealer and the battery/charger model is £75 + shipping.

Jc.

LEDs are not good when run on rechargeable batteries.  They are very
voltage-dependent.  I have done the measuring with a light meter and the
output on NiMH is roughly halved compared with fresh alkaline cells.  If
you use LEDs, I strongly recommend lithium AA cells, as they are a full
1.5V with a much flatter discharge curve (and, as a bonus, are spookily
lightweight).

As you want to use rechargeables, a reasonable 4 x AA halogen lamp will
fit the bill.  Cateye make a Micro-Halogen one and, if you can find it,
the Energizer halogen lamp is pretty good too; sometimes it comes as a
set with a halogen *rear* lamp of identical design and power, which is
probably overkill.  They both use 2.4W 4.8V bulbs.  You get just over
two hours' run time on mere 1300mAh cells, so the modern 2100mAH or
2500mAh cells will give you up to 4 hours, and just enough light to see
by.  The bulbs last a very long time in my experince - in fact, I've
never actually had one fail although they get a bit dimmer over a long time.

Krypton bulbs are just a little brighter than standard torch bulbs, and
not worth considering.  Xenon is a much-misused term, either meaning
halogen bulbs with a bit of xenon gas in them so the filament can be
burnt harder, or a full HID arc system, but you won't find xenon in any
lamp intended for 4 x AA power.

I haven't seen a EL-530, but I'd /guess/ that like most Cateye lights it's
unregulated (meaning the light output quickly decreases as the batteries
run out), and that it probably doesn't have quite as good a beam pattern on
the road.

Anthony

That's an overgeneralisation. Regulated LEDs lights are available, which are
entirely voltage-independent over the normal operating range of
alkaline/NiMH batteries.

Anthony