Normally I frown on buying anything for bike. Off of Ebay, Amazon, etc.

But what is everyone's opinion on this helmet light: Amazon.com : CycleBeam(TM) 700 Lumen Helmet Light Small Size Light Weight Bike Light | Rechargeable Bike Headlight | One Year Warranty | 30 Day No Question Asked Return | 100% Satisfaction Guarantee : Sports & Outdoors?

Unfortunately, you won't find lights that are that bright for that cheap anywhere else. I don't have direct experience with the CycleBeam but I have other lights that use the same emitter. They are good rugged lights for dirt cheap. You can probably find others that are about half the price of the CycleBeam that are marginally larger. It does come with a USB charger adapter if that is important to you but it also uses the normal cylinder plug you find on other light. That's a nice feature as well since it make replacement batteries easier to find.

On the plus side, the light is small and cheapish. On the negative side, it's more expensive than other offerings. Roll your dice and move your mice.

My reason for asking. Is because it doesn't look gargantuan. Yet has the same power as my headlight. I normally don't use a headlamp. Until I saw this. But, I am not fan of buying from non-'brick n' mortar' businesses. Where there is no real guarantee.

Let's compare this light to a brand name top end light like from light and motion -
https://www.amazon.com/Light-Motion-U...S1JAG7QF0BYDXC

Most likely:
1. The cheaper light usually puts out about 50% of the light the brand name light does despite similar lumen ratings (cheap lights list the theoretical maximum, brand name lights list the actual output)
2. The cheaper light is far less likely to actually be waterproof
3. The cheaper light is far more likely to come with a substandard battery that doesn't last nearly as long as claimed, and will wear out sooner
4. The cheaper light is likely to use a led with a color temperature that's more purplish and harder on the eyes
5. No warantee (though let's be fair, a lot of times warranties on brand name lights are not phenomenal either, requiring proof of purchase and sending the light in and being without a light for weeks, and often paying the shipping yourself)

On the other hand:
1. You could literally buy 3 of the cheaper lights for 1 of the brand name lights because of the cost difference

Agreed, though I'd offer to compare that light to the $86 Cygolite Expilion 850 USB Light with Helmet Mount or the $69 Cygolite Expilion 680 in addition to the $135 Light & Motion Urban 800.

Thanks for pointing those other ones out. I made a mistake in my post as well, didn't read "helmet light", if you wanted a helmet light from Light And Motion it would probably be the Stella:
https://www.amazon.com/Light-Motion-S...+motion+stella

$100, 500 real lumens. It's actually somewhat closer in cost, as the cheaper "700 lumen" light probably puts out around 350 lumens for $45, the Stella puts out 350 real lumens for $100. Other points are the same.

Cheap Light: $45, 350 real lumens (most likely)
L&M Light: $$100, 500 real lumens

Your list of "most likely" is either over stated or just plain wrong. I've had Magicshine...which was the first group of cheap LEDs...and other LEDs over the years and few of your points hold up to my experience. About the only one is your first point which I'll admit is mostly valid for a lot of lights. The Cyclebeam isn't claiming 1200 lumens, however. The 700 lumens claimed for a Cree XML-L2 is right in the factory spec.

As for your other points, All of the lights I've used are waterproof. All of the batteries I've had have had run times well within what I would expect given their Ah rating. All of them have had bright white light output. And I haven't needed a warranty in around 8 years of using the lights. Frankly for $30 or less, I don't need a warranty.

I do have a Cygo Expilion 800 (which is very similar to the Light and Motion) that I paid way too much for that does not in anyway put out 800 lumens as claimed, is dimmer than the $30 Magicshine clones I own, doesn't have nearly the run time as the clones and, at $130 I paid for it, would be prohibitively expensive to have a second one as a helmet light. I only use it this time of year when I don't need a light for more than a few minutes each morning.

Before you go saying that I (or anyone) only need one light, I'll tell you that I've had too many failures from many different incidents to depend on only one light. That includes an icy crash that left me with 2 completely broken light mounts and one helmet mount that was only mostly broken. Without that only mostly broken mount, I would have been looking at a long cold walk home.

You are guessing on the output of the Cyclebeam. It's claims aren't over that top as many other lights are. 700 lumens isn't an outrageous claim and they do have a new Cree emitter that has about a 40% higher output than the old XM-L.

And, if you look at the link, there is only one Stella for $99. The usual cost is $199 which is the price that Chris516 would have to pay if he bought it at a brick and mortar store.

I doubt that you are going to get ripped off. There is a guarantee, however. Says so right in the title "100% Satisfaction Guarantee". Read the reviews as well. They seem to say that it is a pretty good light at a very good price.

I'm not going to get into a "try to turn it into a black and white decision" debate.

There have been some problems with waterproof and battery runtimes and reliability with brand name lights as well, but they tend to happen a lot more with cheap lights. The magicshine battery went through a whole series of battery drama incidents including catching fire, but more often just shorter runtimes than claimed. I remember one guy bought 3 of them on amazon, found 2 of them lasted 1 hour and one of them last 2 hours on high.

You can still buy 2-3 of them for the price of another light though, so it's a tradeoff not an easy decision one way or the other.

I don't have time to write out the difference you get in light output between different led's and manufacturers. It is true that several brand names also put out light that has more of a blue/purplish hue, but Light and Motion and also Phillips have put out some really nice light output at night that my eyes like a lot better than the cheaper led's with a purpleish/bluish hue. It's a hue, not an actual color, the light still looks whitish. But some whitish is easier on the eyes than other whiteish.

The Light And Motion products I've purchased have always been very good, and also very expensive. There's good reasons to buy them, or not to buy them and get something much much cheaper.

Some helmets don't require any additional adapters and straps to fit the light. The Bell Sweep is a fine example because it has a horizontal rib running though the center vent that will position a light with the correct loft for riding. All you need to do is wrap the o-ring from the light around the center rib of the helmet and route the wire through the helmet to the battery. Using whatever method works for you, stow the battery off the helmet. I just use the standard Magicshine style light with the updated XM-L T6 emitter and stow the battery in a camelbak. At 10 bucks for the whole shabang, what else do you need? The light itself only weighs 112 grams, about the weight of an iphone 5S.

[h=1]"30 Day No Question Asked Return | 100% Satisfaction Guarantee"
[/h]
Why all of the drama?

I am very happy with the Searfas Thunderbolt as a helmet light. It has a very wide beam pattern to accomodate your head moving around, and it is very light. The light output in lumens is not real high, but if you see it in action you would think it is much brighter than the rating states. It has a whole bunch of micro LEDs arranged to appear as a much larger source. It also throws light down your back so your body is lit up as well which helps a motorist get a depth fix on you and see you are a biker, not just a bright spot.

I'm not sure which Serfas Thunderbolt you are talking about. This Serfas Thunderbolt has 15 micro LEDs but I wouldn't call it a "helmet" light. At least not for the kind of application that Chris516 and many others want a helmet light to do. This might be a good "be seen" light but I doubt that it would work very well as a light to illuminate the road to avoid road obstacles. For that most people want a brighter light with a more coherent beam.

The twin rubber straps are very versatile and my whole faamily uses these strapped horizontally to the rear helmet adjusting strap. This positions it very nicely to shine relatively straight back and illuminate your torso from the rear.

And I just realized you guys are talking about a helmet mounted headlight. I thought you were looking for a helmet mounted tail light. My bad! I should have checked the link first before responding.

Well if you are looking for a helmet tail light, check this one out...

That makes a bit more sense. Serfas also makes a white front facing light in the same configuration which is what I linked to.

And you didn't paste the link.