Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4915611.
I like to use a standard 500mL water bottle when I am cycling, but the water bottle cage on my bicycle was designed for a slightly larger bottle. Occasionally the water bottle would shake loose and fall off the bike. It can be inconvenient and also hazardous if the bottle hits the rear tire.
I designed this simple support to prevent a 500mL bottle from slipping through the back of the water bottle cage. On my bicycle, it fit snugly into the groove of the water bottle cage and fastens using the existing bolt.
It should print fine in its default orientation, however I chose to lay the larger side flat on the printer bed. I printed mine in eSun PLA+ with 0.2mm layers and 15% infill. On an Ender 5 it took roughly 40 minutes to print.