anyone know anything about this thing?

900 Lumen LED Bike Light

Looks like chinese stock. Even so, how much could if be overspec'd for? I would find it hard to believe that it is less that 500 lumens. and with a battery the price tag seems pretty good.

It is Chinese junk, it will put out about 300 (give or take 50) lumens of actual light. And if your lucky it will last just barely past the warranty period, then you can buy another one. And the battery will last half as long as they claim.

Remember, you get what you pay for. I'm too cheap to buy cheap products.

Cygolite makes great lights that put out true lumen and battery life quotes...but yeah, you do have to pay more.

Yes, they're a dime a dozen coming out of the Chinese factory...
Here's the manufacturer's link from alibaba
https://magicshine.en.alibaba.com/pro....html#products

You can find some comparative beam shots here next to a more realistically rated light. Keep in mind Lumen vs. Lux, where Lux takes into account the surface area over which the light is spread. So rekmeyata's estimate is probably pretty close.
https://sites.google.com/site/design...ot-comparisons

An interesting video comparison here:
https://sites.google.com/site/design...ght-ride-video

I don't have any plans on buying it, as it doesn't work into my budget. I already have some lights that work fine for general road use. Eventually I plan on fabricating some high powered LED's on my own for riding on trails and such.

Mainly just curious. 900 Lumens seems like a lot, at "0ver 3 hours" and under one pound including battery. Trying to get that sort of power over 3-10 watt LEDs without beefing up the batterys would sound implausible.

900 lumens is a lot to have just riding at night with. I have a Cygolite MityCross 480 and I rarely ride with it on high.

I had a MagicShine, it lasted 2 months, I sent it back to Geoman and never heard anything more about and that was after 4 or 5 dozen e-mails, now 14 or 15 months later nothing. They only have a 3 month warranty because they know how cheap it was. And that was my mistake for buying such a thing, but I ignorantly thought that since all LED's come out of China anyway that maybe they can make them that cheap and last...nope. And that Magicshine was no brighter then a Cygolite ExpiliOn 350 I also bought and the ExpiliOn lasts longer in battery usage, as does the the MityCross.

Someone here tested i with a meter a year or so ago and the light puts out a real 380 to 450 lumens. The latest version with the Cree xm-l emiter will be much brighter.

I don't think the term "much brighter" is very accurate. And at the price mentioned you could almost get two old lights for the price of a new X-ml version.

I do agree that the "lumen" count is a tricky issue. The MS 900 uses a "floody" reflector makes brightness comparisons with many lights difficult.