On Mon, 22 Sep 2008 08:36:29 -0700, Richard strung these words together:

Can anyone recommend me some lights please that are powerful enough to
use along the unlit part (how many watts / lumens do I need for this?)
and also legal for the road, and given this as cheap as possible.
Ideally they should be easy to remove from the bike when not in use and
use a power source that can be recharged easily.

Some of the lights I have seen use LEDs, some traditional lightbulbs. Is
there any advantage to either?

LEDs are much more efficient than incans but the high output ones (Cree
XREs, SSC P7s, comparitatively old-school Luxeons) need quite a bit of
heatsinking to keep from frying if they're being run at anything like
nominal output for any length of time.

A word on output.

For a seeing-where-you're-going light on (for example) a stretch of
pavement that's not completely pitch black, but not deliberately lit, I'd
say you need at least 120 lumens to cast a pool of light about three
meters in front of you (assuming a handlebar mount)

For less than £45 you will be able to find a torch (and mounting bracket -
twofish lockblocks are good) with about 130 - 200 lumens of output and
over one hour of runtime and (probably) enough heatsinking to cope /and/
that runs on AA cells (though you're better off going for a R123 setup for
200lm plus), that'll fit in your trouser pocket.

Or, there are LED dropins with PR-bases that'll probably fit straight in
your existing light (just pick one for the right number of cells), from
SMJLEDs (I have one of these and it'll put out the same pattern and amount
of light as a standard Xenon 2 cell bulb for 20 hours or more, though it
has a pronounced blue tint) to CREE/Seoul dropins (again, heatsinking can
be a problem), all of which, you'll be able to pick up for ~£20.


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