Probably enough to be seen.... Might not be enough to actually see the road though (depends on your riding conditions
).
I ride with a 4 LED blackburn headlight (with collimation lenses) mounted to the front of my bike and a 10W halogen on my helmet.... Then a 7LED chasing red rear light (apparently blinking lights attract drunk drivers).
Part of my route home is at night on a road without street lights :/
My bike is also bright yellow
And, my tires have reflective sidewalls. AND, working on my
I'm trying to find a suitable lens for a 5W luxeon LED so I can project light ~30 feet in front of me
Be sure to use rechargeable batteries
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EDIT
I also agree, lights are not something to skimp on.... Recently, someone that goes on a ride I do got hit by a car.... He was in ICU for something like 1.5 weeks, now is in the progressive care unit and apparently, will need to go through speech therapy (brain damage - how much he recovers is still unknown). This is second hand info, but the fact is - it wasn't exactly daytime....