iH-500-STD PHONE GRIP Handlebar Mount for 22.2-28.

The Minoura iH-500-STD PHONE GRIP Handlebar Mount for 22.2-28.6 mm Bars is a handlebar-mounted smartphone holder with a fixed LW clamp that fits phones with a width of 55-77 mm (2.16-2.95 in) and a thickness of 6-18 mm (0.24-0.70 in).  Lightweight at 141 grams, it will hold your smartphone steady even while going downhill.  Its height is user adjustable, and it can be rotated 90 degrees.
Handlebar-mounted smartphone holder with fixed LW clamp fits phones with width of 55-77 mm (2.16-2.95 in) and thickness of 6-18 mm (0.24-0.70 in)
User-adjustable height; can be rotated 90 degrees without any tools
Holds phone steady even while going downhill
Lightweight at 141 grams
Fits handlebars from 22.2-28.6 mm