Alternative O Ring Mounting Solution
Finally had time to mess around with this.
I mounted this light with these direction I wrote up for the mount below. For other lights with better threads this be easier.
Then go to the hardware store and get a M4 flathead machine screw that is 10 mm long. Take the base place off that came with the light. Its more epoxied on than screwed on. Attach the base plate with the 10 mm M4 screw. You will also need to flare out the top of the hole on the new base plate with a knife or drill bit. With luck you will catch 3 or 4 threads on the bottom. Because of this you will also need to coat the M4 screw with JB Weld adhesive. Clean the pieces to be epoxied per the instructions. Clear nail polish remover works well. Also fine sand paper. I also used a secondary plastic adhesive (3M Hi-90) for the plastic part to help keep the base plate from rotating but tht might not be neccessary and the JB Weld may also bond the outer plastic surface to the light housing. Screw the M4 into the light and let cure. Its a very strong attachment. Attach the other piece to the handle bar. If it slides around add a layer of self curing tape from the plumbing department of your hardware store. Very solid not the cheapest option. About an additional $35.