Mounting a GoPro to a motorcycle helmet can be challenging. In order to effectively control the camera, the rider really needs to be able to see the back of the camera. This mounting option puts the camera in the lower 1/4 of the riders view and positions it for easy attachment of a helmet mounted microphone.
At the time of this video, this entire setup cost $29.50. It greatly improved the quality of my GoPro trail videos.

Hero 2, 3 & 4 Mic: https://amzn.to/3h8yrRC
Hero 5 8 Mic adapter: https://amzn.to/2Fu8qhs
Cheap Lav Mic: https://amzn.to/34dtrY4
Mount Link: https://amzn.to/3l7GxfI