Updated: Sep 9, 2020
Now, there is nothing wrong with the Telletubbies look of sticking a GoPro on the top of your helmet. The pros do it week in and week out, but...
You can do it better. They are really using the footage to help with line choice and race analytics. You are making art. Since you are making art you need to put your camera in better places than right on top of your dome.
Chest mounts are great, but sometimes hard to deal with, welcome the Pro Standard Super-Visor.
It is a first of its kind, low profile under visor mount. https://www.prostandard.com/collections/pro-standard/products/super-visor-low-profile-under-visor-gopro-mount
It fits right up under your visor and give super rad perspective to your riding. It works for Moto, BMX, MTB, anything that do with a helmet and a visor.
I have been using it for about a month now, it fits my Osmo Action and my Hero 7 with no problems. You do catch a glimpse of it out of your peripheral vision, but you forget about it pretty quickly.
The owner/founder Ken Achenbach has been making movies and shooting photos for over 40 years, he knows a thing or two.
Here is some footage from the Pro Standard YouTube page.