Hey jdawg, I used to mount my ATC cameras on the side of my helmet using 3M 2-sided sticky foam pads. They work really well and you can carry spares in case the camera mount breaks off. They hold well, and the only times I've had a camera come off is when I've fallen and whacked the helmet on the ground. The foam allows the pad to compress differently in different spots, so if the helmet isn't perfectly smooth you can still get good contact of the adhesive area with the entire surface.
Here's a link. You could order them, but I think you can buy them at stationary stores or drug stores around S'toon.
https://www.amazon.com/Scotch-Mounting- ... 3KREZMC5MQ