I wanted to get something which can be taken off the bars and carried along, as well as work well during the ride. After studying some of the light candidates, I decided that the Lumapower D-Mini VX Ultra using the SST-50 looked like a very good light choice. It offers 550 lumens on the high setting, and around 200 lumens on the medium setting. For the short rides I do at night, the ~90 minute runtime on the high setting is more than enough for me.
I chose the Twofish Cycleblock mount. It is a good secure universal strap mount for about $12.
All in all, I am very pleased at the lighting this provides on an 18650 battery, and for only $112 with mount. The SST-50 with this reflector offers a great floody beam. It offers a good balance of throw and coverage for a bike ride.
Edit: Sorry for posting here, this isn't exactly a DIY light setup!
Mtbr's 2016 Winter Biking GearReviews and Roundups
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