With LEDs there is always something new just around the corner, and the new stuff creeps up very quickly. I had heard about COB LEDs but only started researching them last week. COB stands for Chip On Board LED. Rather than go into an explanation here I recommend that you have a look at this link: CLICK HERE. That should give you an over view.
I was on ebay like a rabbit and came up with some COB strips 15cm long and advertised as being 6 watts. A pair was less than four pounds sterling (5 Euros). I ordered a pair of white and a pair of red to play with. the red ones came with a black aluminium frame and the white with a silver frame. The frames can be removed and swapped around or they can be used without the frames.
The explanation to the picture as as follows: On the left is a frame that I have removed from the first COB which is a white COB despite being yellow when switched off. The second COB is also a white one with the frame still attached. The next two are red COBs with black frames. These can ba attached with any modern waterproof double sided tape. If they are to be used where the rain could get to them then I will take all the frames off and cover the soldered terminals with a blob of silicone seal.
This is one of the white ones and it is even brighter than the red. These are such a leap forward that I would imagine that using one of these as a DRL on the front of the bike will make you very noticeable. I do not believe that they use as much as 6 watts, but they seem to be very efficient. You could not use these as an aid to driving in the dark, they are not designed for that.
The red one fits perfectly onto the rear of the standard ST pannier as an auxiliary brake light – it is far too bright to be a rear marker light. If you want it to function as both then a small 510 ohm resistor will dim it down enough to operate as a rear light and then bypassing the resistor restores it to full brightness.
I have considered fitting both the red ones into the ST standard rear light with one row coming on dim through a resistor, and then both rows coming on bright when the brakes are applied. I will look into that and report back.