A while back in a boating/fishing forum I was turned onto the RAM universal mounting system. Since then I use them in my boat, car, and bicycle for everything from my Gopro (hat, bike, boat and car mounts), RADAR detector, GPS, and phone. I have yet to find something I cannot do with them.
On my mtn bike I have my phone (for a bike speedo app) and one of my Gopro mounted.