This is a (perhaps riduculously overly ruggedized) smartphoneholder for bikes, scooters, etc.
I designed this for the Pixel 8 Pro wearing a silicone cover, but any other phone with a width of ~8 cm will also fit. The fixture fits a handlebar with a diameter of 22 mm.

Additional Material:

• 4 M3x20mm bolts
• 4 M3 Nuts
• 1 M3x40 mm bolt
• 1 M3 Threaded inset

Assembly:

• Fix screw and base to the handlebar with M3x20 bolts and nuts. Solder or press a threaded inset into the central hole on the side of the base.
• Glue a M3x40mm through the knob
• Stick slider into the base
• Stick the knobbed screw through the slider and screw into the base
• Optional: Glue some patches of soft material (felt or rubber) on the inner vertical walls of the base. This can also be used to adjust the width for smaller phones.