Bump!

Project completed! I will try to post some pictures & beam comparisons if I get a chance.

The adaptation of the Cateye HL-1600 went more or less exactly as anticipated. The bulb holder reflector and lens assembly was removed and a new back plate made from sheet aluminium to replace the reflector, and offer a mounting surface for the LED. The LED used has built in beam forming optics (see picture) and is mounted to a heat sink plate. The heat sink was reshaped slightly to permit positioning and alignment within the clear lens from the lamp and secured to the new backplate using 2mm nuts and bolts. Wiring was completed with a 10 ohm series resistor to take care of the excess battery voltage (around 6.5V in practice) and ensure correct current supply to the LED.

A quick check in the darkroom here at work suggests that this setup has the potential to outperform the 4.2W halogen setup in the "turbocharged" HL1600 that is my main lamp (regular spec was ~2.4W). A few tests on the road will show up any differences. I'm impressed with the brightness and also the blue-wight hue that seem more noticable in traffic, when seen on other bikes, compared to the yellow tones of the halogen illumination.

I'll post back with a ride report soon.

Cheers,

Ed