I have the same phone, I user the Quad lock system, I have a handle bar mount on the left side, run a charging cable up from the left cubby that plugs into the waterproof wireless charger mounted to the vibration dampener, I use a ball mount that attaches to the clutch fluid mount screws. I've taken my F6B offroad with this thing mounted, it will not fall off, when it's locked in it isn't going anywhere. https://www.quadlockcase.com/collect...%20S21%20Ultra