This video explains how I capture full-length gravel race videos.

The essential parts are:

• GoPro USB Pass-Through door: https://gopro.com/en/us/shop/mounts-accessories/usb-pass-through-door/ADCOD-001.html
• A USB C cable. I use an L-shaped one that has a water seal around the plug: https://www.outboundlighting.com/products/usb-c-to-a-cable. This has been great, even in terrible conditions.
• External USB battery pack. I have a couple different sizes depending on the length of the event. I used this one on Sat: https://www.amazon.com/gp/product/B07L931FCY/. Most packs will work, but you need to make sure that they deliver enough power to the GoPro. It will turn off if they don’t. The first few that I tried didn’t work. Anything that does QC 3.0 has been solid for me.
• Top tube bag, or somewhere to put the battery. I have an Apidura one that has a hole in the top intended for cable pass-through: https://www.apidura.com/shop/racing-bolt-on-top-tube-pack/.
• Electrical tape to secure the USB cable to the stem so it doesn’t get yanked out or pull on the GoPro in an undesirable way.