I have ridden with my Niterider Storm HID mt bike light for about 5 years. I’ve tried it in both locations: handlebar mount and helmet mount. Let me tell you what light location works best for mt biking at night.
Handle Bar Mount:
Pro: the light and battery are not on your body, so you feel more comfortable
Con: the light is only pointed where your bike is facing so switchbacks, looking over your shoulder, etc are not lit up.
Con: if the terrain is bumpy the light beam with shake all over the place
Helmet Mount:
Pro: you’ve got a bright beam anywhere you look and it is more steady than a handle bar mount.
Cons: if its dusty then you lose some visibility and you have to carry the bulk light and battery on your body.
