As I suspected, this is only any good to make you seen, not to see by, it simply allows too much shaking on anything but dead smooth surfaces. I used it with an 18650-powered Convoy S2+ (24mm, 125g), which must be perfectly representative of what it's intended for. Tried the small bands for both handlebar and torch. I dare say there might be hacks to improve things (the bracket definitely doesn't grip metal (.e. the bar) well and part of the movement is its actually rotating on them), maybe some bits of inner-tube, gaffer tape, whatever. That said, perhaps the shaking makes you more conspicuous than a solidly mounted light would!