NEW AND IMPROVED BICYCLE BOTTLE CAGE HANDLEBAR ADAPTER/MOUNT!
Wanted to make the bottle cage adapter with a little rounder, nicer shapes and I did. Print as you wish, pay attention to strength in the settings you use. These are designed with PLA in mind, hence the slightly bulky appearance - bulky, but rounded.
Available clamp diameters are 22.2mm, 24.0mm, 31.8mm. Feel free to design and print a shim if your handlebar has other diameter and none of them come close enough. For the clamp you need M4 nuts and hex socket aka allen key cylinder head bolts, 16mm long for the 22.2mm and 24.0mm and 30mm for the 31.8mm. To mount the bottle cage on the adapter you just use the regular bottle cage standard M5 bolts with M5 nuts.