Just find this bike link on youtube , it said have 900lumens , was it really have 900lumens?
Anyone who every buy this bike light , and what do you think of this bike light ?

This is the video from youtube : http://www.youtube.com/watch?v=mLjGUFSZKWg

Bought it for my wife, she can't see well when it's dark. Now she is driving like mad in the night.
It is very very bright, usual Bike Lights are like a candle compared to this.

The only weakness so far: the O-rings are very poor designed, both broke within 2 weeks here. So it is a good idea to get an alternative early.

Do you mean this one?
It's pretty bright. A lot of german mountainbikers bought this and are satisfied. The battery is not the best, but for this price ok. Someone made measures with that and found about 500 Lumes what is a lot.

If it can output 500lumens , it also OK , it seens this bike light are very popular, and discount for this light if buy it now ?

Two people I know bought such a light and both had problems.
One had an inexplicable failure after three months (I guess it was the known
problem of not enough thermal paste under the LED), the other had water in the housing
after an exceptionally heavy rainfall after a year of use.
Still, it is a lot of light for little money and if you are careful,
it is a decent short-term investment. Not my personal style, tough.

i'm happy with it, so far.
good light.
i haven't test it on realy bad weather. many friends have, so far no one complained.

Quite simple plug socket, if you're asking me. But for this 78.- bucks copycat it is apt. You got the idea.

Its awesome bvut quiet expensive

It looks really cool and its not that expensive anymore. There are many Shop in the city that provides all these kind of lights now.