Anybody using or have a view? Am wondering if they’re any good?
Yeah I’ve often considered buying one of those Cree high powered torches. There’s probably a few things worth considering before you buy though:
-The bike mounts are pretty crap (this is a very important component otherwise all you have is a torch) My boss bought a similar one and the mount is pretty cheap and nasty.
-The battery pack is very rudimentary- no Li-Ion batteries here.
-Even with 3xNiMh rechargables, the battery life will be very short.
-Wonder how durable it is- is it waterproof do you rekcon?
Having said that there are some really cheaps ones on ebay- cheaper than $77.00 too. They’re no Ayup, but they probably do the job.
I’ve had the same reservations, so I thought I’d put it out there to see if anyone can dispel them. Currently running some old Cygolites I’ve had for years (2x10w halogen), they throw decent light but battery life is crap and SLA 6volt batteries are HEAVY and take all night to charge.
Another question - anyone know what a ‘lumen’ really means? I have JFGI for a definition but I still can’t relate how a claimed 200+ lumens would compare in the real world with my 2x10w halos on full…for actually being able to see?
Blakey?
Search yacf (yet another cycling forum), they did an exhaustive test on lights recently, dyno and battery I think, so you should be able to get some comparison shots (at fixed exposure) of different wattage LEDs / HIDs / Halogens.
Also, Peter White has some comparisons on his webpage.
Buy Ay-Ups / Dynamo + B&M IQ Cyo and be happy. The quality is remembered long after the price is forgotten.
Being a lighting designer, I should be qualified to answer this… :mrgreen:
Basically lumens are a measurement of luminous flux coming out of a lamp. Think of lumens as the quantity of light that a lamp produces. It is a useful measurement for comparing the power of lamps.
People often get confused when talking about candelas, which is a completely different measurement of intensity or brightess at a particular angle. LEDs are often measured in candelas because LEDs tend to have very high intensity at a small angle. But this tells you nothing about how much useful light the LED produces, only that it is glary… :roll:
Lumens are the only way to really compare apples with apples so to speak.
For instance, a 50W halogen lamp produces 950 lumens. Your 10W halogen lamp probably produces about 120 lumens. So two of those produces 240 lumens.
So technically, the 205 lumen Cree LED is going to produce marginally less light than the 2x10W halogen that you already have. Of course, the LED is much more efficient, producing about 60 lumens/watt compared to 10/lumens per watt for halogen.
LEDs give the impression they produce more light because they are intense, but this is only because they are ‘bright’ or have a high candela value at the centre of their beam. For instance, a generic flashing front LED probably produces only 10-40 lumens.
Another thing worth noting is that a cooler colour-temperature appears ‘brighter’ than a warmer colour temp. For instance, a 5000 kelvin white LED of the same intensity will appear ‘brighter’ than a 2800K halogen lamp. This is due to the sensitivity of the human eye.
It can get quite confusing… 
i’ve just installed a ‘900 lumen’ led setup on my bike. cost me $70. Expected battery life is around 1 hour at full steam. basically its just a torch on a mount, but should work ok. and this way i have a torch as well, and it can be removed and remounted in a few seconds.
also, while the manufacturer rated lumens is 900, apparently around half that is probably more realistic, but still good value. will post pic up tonight.
An easy way to get more light out of an LED is to over-run them. Of course this has negative impact on their lamp life, especially since they will run a lot hotter. I can imagine a 900 lumen torch will get pretty hot during use.
Crudely-painted, not-so-funny plywood cut-out folk art!
where sensitivity of the human eye is broken up into 4 parts:
red cone receptors
green cone receptors
blue cone receptors
rods
cones basically act in colour when the amount of light is reasonable. They are focused around the centre of your eye (I forget the precise term, but centre would be opposed to one’s peripheral vision) where your vision focuses. rods are evenly spaced throughout your peripheral vision.
led’s produce white light, or even wavelength across the spectrum of 400-700nm, whereas warmer light isnt as evenly spaced, and therefore isnt picked up by as many receptors.
Funnily - I’m also a lighting designer - and a good trick to use when focusing lights (especially in circus, when people are prone to being ‘dazzled’ and lose their orientation) is to put some light blue (201) in front of the light, and even though the intensity of the light is barely changed, the spectrum has, and it ‘appears’ more bearable.
rods on the other hand only pick up light (as opposed to dark) and arent really spectrum specific, they arent good at being focused, but are good for seeing (you know how you look away from what you’re looking at in the dark, and often it appears brighter/more defined then? this is because the rods are working for you, and there are no rods in the central focus of your eye)
Light’s a funny old game, really… A wave, and a particle! (any physicists here?)
Now there’s the answer I was looking for - thanks H.
Am I imagining that the ‘yellower’ light my halogens throw is more helpful for picking out detail like small rocks & stuff than the blue/white LEDs? Is that another of those ‘how eyes work’ things or am I full of crap?
Can I vote: ‘full of Crap?’ 
Buy Dinotte, commuter light 1 year going strong…
Less full than I was 15mins ago 
I’m not entirely sure- my guess would be that the cooler LED light (and the LEDs used in bike lights are always cool as the 5000+K LEDs are the most efficient per watt) would stand out more on the road compared to halogen light.
This is also enhanced because the background streetlights are usually high-pressure sodium which produce a very golden light.
The main advantages of LEDs are long lamp life, and energy efficiency (compared to halogen)
they did studies on this in england… from memory it depends slightly on atmosphere as well (ie: is it foggy/cloudy?)
with atmosphere there is a massive difference between yellow and white lights, for lumen vs Kw/H, which is why they have sulphur street lamps… the visibility you get out of them is pretty amazing, considering that they arent that bright (in europe a lot of car headlights are yellow as well, which reduces steez, but improves visibility as well)
i just hope that these folks are paying respect to the indigenous people whose name they have appropriated for their product line.
The simple answer is that for scotopic vision, the eyes sensitivity moves towards the blue end of the visual spectrum:
(right click to see larger version)
Therefore the eye is going to be more sensitive to a cooler (bluer) LED, than to halogen.
Paging Dan to the thread. the Sheldon (PBUH) of torches.
not to discredit flickr, or wherever the source is from, but the relative sensitivity of red drops to practially nothing, which would mean in low levels of light, we wouldnt see red.
It also doesnt correlate with almost every theatre in the world using backstage blues, rather than backstage reds…
I can’t remember being taught that the sensitivity of rods changes across the spectrum in lower level of light when I studied it. Will have to do some research 
Hey guys, be careful with the handlebar mounting brackets on SOME of these ‘oh wow you can have a torch AND a bike light at once!’ lights getting around of late.
The brackets tend to have less retention on the ‘torch’ especially on rougher terrain ie: hitting train crossings, harsh potholes, riding down gutters or offroad tracks etc…
Ive seen/heard of a few of the Cannondale (and generic brands) popping out of the bracket and hitting the deck.
You might want to head down to Bunnings after you purchase one of these lights to buy a couple of appropriately sized O Rings to hold them into the bracket sufficiently.
Perhaps these ‘ebay’ ones are fine, but it could be a good precautionary measure…