This fits a 25mm handlebar and will fit an iPhone 5s in an Otterbox Commuter case. Does a pretty decent job of it. I wish the uprights were a bit thicker. I used some superglue to lock it together and plastic zip ties to secure it to the bar, although it has a fairly solid grip.

Customized version of http://www.thingiverse.com/thing:426872

Created with Customizer! http://www.thingiverse.com/apps/customizer/run?thing_id=426872

Instructions

Using the following options:

cornerradius = 12

mountheight = 20

$fn = 100

height = 14

tubediameter = 25

length = 131

width = 65.5

bridgewidth = 20