I agree with one of the other observations about disc brake systems, my work bike is a hydraulic disc system, which has no cable movement to trigger a switch, this bike is the one that I would be wearing the helmet on for the vast majority of my riding time. Hydraulic disc brake systems are becoming much more common on many types of production bikes, which could mean many riders Lumos brake light operating systems may not be compatible. So for me the options are to either drop the braking feature entirely or work on perfecting the current system.