A fresnel lens can also aim the beam by the way, it just depends on where you cut it. Something like this https://www.amazon.com/OpticLens-Fle.../dp/B00ET4936A (not necessarily that one, but for example), just cut out a piece in the same shape as the light and slip it inside the light's lens cover. In the center for symmetrical spreading out, a piece from towards the edge will angle the beam. Some light will be dispersed or blocked of course, they aren't perfect. Just an FYI

I tend to mount all my lights this way, underneath the handlebar or on the stem underneath, because I like them out of the way.