I have seen a guy riding MTB Downhill and filming using iPhone and this contraption. He said it works fine. I had hard time believing at first, but then saw hi

I have seen a guy riding MTB Downhill and filming using iPhone and this contraption. He said it works fine. I had hard time believing at first, but then saw him riding a couple of times throughout the day and the phone was indeed where it was supposed to be. So I reckon it should work for the majority of use cases.