Used the original and adapted to fit my iPhone 7s (the big one) with a 3d printed cover from thingiverse (www.thingiverse.com/thing:1942852) and to fit my motobecane HT550 mountain bike.
I will use rubber bands or Velcro straps to hold the phone down to the holder. It fits snug now with my case and such so smooth paths and front forks may not need rubber bands. But I will use them all the time. There are little nubs under each end of the arms. Those are to keep the rubber bands from slipping over the ends of the arms.
I put a few wraps of electrical tape around the bar to help hold the item in place and to help keep it from spinning around the pipe.
I use a Bluetooth connection so I did not worry about access to the plug. But I am considering another version to slide one way or the other for that access.
As always, no warranty is implied or given. Use at your own risk, damage to your electronics is your responsibility. There, the legaleze is complete.
It seems to work for my application. I will update with it's performance as I put miles on.
Thanks for looking!