A typical week has me finishing a century ride, and, coming home a few miles after a group ride in the dark. Most of the time, most of my bikes have lights mounted on them. Including my weight weenie bikes.

I was bored a couple of days ago, so I bought one of these.

$4.16 really !!

FJQXZ Red Light Water Resistant LED Warning Tail Lamp for Bicycle - Blue - Free Shipping - DealExtreme

It's been running 8 hours so far with no noticeable change in brightness.i rode with it for maybe four hours. It's not quite as bright as my 1 watt Radbot 1000. It's close to the same as my Planet bike Superflash .5 watt. It's noticeably brighter than my brand new Planet Bike Superflash mini USB, which is not bad. It uses two cr2032 batteries, I can get them on line for less than a dollar. The rubber strap may break, but if it does not damage the light I will put velcro on it. If it smashes to the concrete, I will just pull another one from bag and put it on. They say waterproof, I have not used it in the rain yet. I ordered a white one for the front.

Four friggin' dollars, yeah .............

Soooo, what's the actual weight? I recently got a USB Axiom Pulse 60 that's considerably brighter than a Radbot with a broader beam and totals 55gm with mount. It's great for broad daylight and bright sunlight but too bright for night use IMO, even in one of the lower power steady modes.

My cheap plastic scale says 20 grams. Not sure how accurate that is. I'll have to look at the specs for the Axiom. I never heard of it. Sounds great.

Ok...that just cost me $39.

Do you have the Radbot 1000 or the 500?

You can get 2032's in bulk for a lot less than $1. If not, the cost of fueling this light negates the savings from the purchase price.

I said "less than a dollar". Without going back to the page, I think they were from around $.75 down to $.55. Without testing a batch of batteries it's difficult to know the quality of any batch of batteries.

The cost of the batteries still may be too much, but it's got about 14 hours on it right now and still going. The run time will determine if the battery cost is too high. I have no preference which way it goes. It is what it is, as they say. If it uses too many batteries I may keep one in my bag as a backup.

I would say I average about 5 hours a week in the dark. if it goes 15 hours, and the batteries are $0.55 that's $1.05 every three weeks. All my other lights use rechargeable batteries. I would have to go back and look up the prices of all my lights and all the Eneloops I bought to compare properly. I think the rechargeable lights still are ahead, but the light is still going. The poorly translated specs on the internet go from 2-6 hours up to 35-160 hours for the same light.Who knows what will happen? I thought it would have died by now. ??? If there are other small bright lights out there than are better, please tell me.

The 1000 is one watt, the 500 is .5 watt.

I have a couple of these on the back of my helmets as auxillary lights. You can get them off eBay as well for about half that price. IMO they aren't bright enough to use as a primary stand-alone light, just as an emergency or backup.

There is a much brighter (40 lumens) USB version out now which I have just bought recently - Cycle Design Safety 40 Lumen Rear Light

I just tried to order one, they are out of stock.

Try this link - Rear Lights | Sprockt.com.au

I just got in a couple of white ones for the front. They came from DealExtreme and were less that $4.00. They had different packaging. The package says "steady 50 hours, Flash 150 hrs". I tested the red one for about 16 hours and got tired of testing it. I'll assume the 150 hours is to when it goes dark. So a very conservative guess, based on my testing, would be possibly, 50 hours on flashing? say 25 hrs flashing, and then it's weaker. I bought 20 cr2032 batteries, they were $0.55 each. The light takes two batteries. For me if I'm riding a lot, I might do 5 hours a week in the dark on average.
With my estimates all leaning a little to the worst possible battery life- 25 hrs / 5 hrs a week = 5 weeks for two Batteries That cost me $1.10.

Making all the estimates way worse than what they claim, this will cost me $1.10 for 5 weeks. Realistically probably longer run time. I'm going to ride with them and see how they hold up. The packaging says "waterproof". At this point they seem to be cheap, bright, good run time, and lightweight. The front or back can be used as a flashlight to see something on the bike, or riding walking speed in an emergency. I would expect steady to the chew up the batteries pretty fast ??

They may have a quality problem, down the road. Pun intended. If they don't break I like them. At the very least, a good thing to have in your bag on a night ride.

As I mentioned in a previous post, I have a red one strapped to the back of my helmet. Does everything it says it does, good value for the money. I've never used mine on constant, only flashing, so couldn't say how long the batteries would last. Never had a problem regarding quality though a mate of mine has with his switching off randomly mid ride.

Also, regarding the USB version I posted further back up the page, I've now found yet another version of it. Not sure if it's the same one rebranded but the original one I posted the link to claimed 40 lumens and this latest one from Tioga is only claiming 15 lumens (run times are same for both)

Tioga RC100 Ruby 15 Lumens USB Rechargeable Rear Light 2014

A white front version is also available but claims 40 lumens

Tioga DC100 Diamond 40 Lumens USB Rechargeable Front Light 2014

Have him take a small piece of paper fold it into a very small shim and put it between the top of the battery and the case. Thick enough to work when it is screwed together. NO this is not a current path for these lights. I did it on a couple.

$3.80 lights.....

yeah, I noticed the first link you posted offered 40 lumens for both, which made me think that, at a minimum, the rear rating was off, since almost always when looking at front/rear designs of the same light, the rear is lower rated (presumably due to red lens).

40 lumens for a rear light is fairly reasonable, similar to say a Moon Comet. 40 lumens for a front light is very average and is just a "to be seen" light, not one you could use to see with. 15 lumens is probably the rating for the cheap $3.80 battery versions.

There are so many different rating methods used for lights, I wish there was some regulation that forced manufacturers to standardize. Some measure in Watts, some in Lumens others mention Cree.

LightSKIN puts the taillight within the seat post itself, so just the Battery and the LED array is added to the seatpost,
you need A Seatpost on your bike? , right? .

Built-in Bicycle Tail Light - LightSKIN

Between Amazon and Deal Extreme there must be 20 different companies selling the same light. And a couple selling something that looks identical, but has different programs. I read the details and, it seems like except three models that are different, the sellers are making up the run times and the lumen ratings. They're all made in the same place, and sold by many names. Just like all the Magicshine copy lights, and every one of the 30 or more tail lights I have used in the last 22 years. I had one favorite years ago, I found 5 brands selling them, I bought one of each to see the difference. Then only difference was one company had different settings.

I found a two setting model of the one we are talking about, a three setting model, and the usb models that Falchoon linked us to.
The other problem is that LED's get brighter every year and we don't know how new the led's are in each light offered, or how hard they are being driven. Maybe some of the different brightness claims are true, but I think not all.

No good when you have 2 many bikes. A good light for me has to fit most of them.

I have 3 bikes with Dynohubs . upgradeitis.. this one has some appeal SON rear light

41 euros is $61. Uh, I don't think so. I think the most I've paid for a tail light is $30.

fietsbob usually recommend products with piss poor value or utility. Take that lightskin seatpost tailight, you have to take the seat post out to replace the battery, and what if you have different bikes with different seatpost diameter? You have to buy more than 1.

As for that SON taillight, DIY tail light is brighter and has a better beam shape, and it cost $10.

I was referring specifically to the non-variance of rated output between white and red models of the same brand, which is itself enough to raise a red flag to me, nevermind the issues of spec variance between brands.

I have a few old bullet headlights and various stuff lying around to build as tail lights that I got in piles of stuff, trades, etc. for waaaay less than that. Since you aren't worried if it makes your bike a RAT, improvise...go nuts.

The only thing I have to wonder is what cold weather does to your batteries. Don't use NiCads, they will turn to MUSH *from experience.

I'm also not sure what benefits are to be gained at NIGHT with a flashing light...and I want to build a coaster brake trigger to light an extra lamp when I stop, of course.