Bike lights - what is bright?

giantsasquatch

You could do what i've decided to do, make your own light very cheaply using a 20W MR16 12V halogen light and get approx. 800 lumens running off 12V which would be brighter than a Magicshine(approx 700 true lumens.)

20W halogen £2
plastic piping £2
battery pack £20
cables and connectors £2
bar clamp holder £2

No soldering required.

Total cost approx. £25 + suitable charger

Goto a diy store for the halogen and clamp,for piping goto the plumbing section. Goto a radio controlled model shop for the battery back and leads. There is a lead you can get that fits directly onto a MR16 lamp.

http://www.reuk.co.uk/MR11-and-MR16-12v ... ectors.htm

You can make it alot cheaper if you buy your own nimh batteries and buy a 10 battery holder which costs less than 1 pound, but then you would have to do your own soldering. You get more loss this way, so less battery life.

I got the idea from here.
http://www.instructables.com/id/BIKE-LI ... 10-bucks-/

giantsasquatch

Strictly you cannot convert watts to lumens as there is no relationship.

Lumens measure the brightness,

Watts measure the amount of power consumed, not light emission.

It fine to use watts if you comparing the same kind of bulb. Using lumens means you can compare the brightness between different bulb technologies.

When you see them compared, it is approximate.

Generally

1W LED = 80 lumens
1W Halogen = 30 lumens

Lumens is the newer term to use.

Also good to note amps and voltage.

These 2 bulbs produce the same 33 lumens.

4.8V 0.50A 2.4W
4.0V 0.75A 3.0W

The 4.8V would be the better choice as it uses less amps,longer battery life.

.

pastryboy

brownleather wrote:

Do you have to pay any extra sort of important taxes when you ordered the Magic shine from Deal Extreme?

Tucked away in the big thread in the mtb section someone posted a link that said they don't apply to purchases from Hong Kong (and a few other countries).

Loads of people on the boards have bought them and not aware of anyone who has paid any extra.

Burghley

Hi

P7 has arrived! Initial impressions off the bike are very good, considerably better than my old Electron setup.

Roll on Monday morning to test in real life...

Rgds

Pete