Here's a set of STL files that allow a 26wheel mountain bike to be wall mounted. While the wheel stands are designed for a 26 Wheel, these should accomodate a 27.5and a 29 wheelset also.

Included in the files are two versions of the wheel stands, V1 one being larger and more durable and V2 being a smaller design (for lighter bikes or stronger printing materials) and a pedal mount to hold the bike against the wall.

I've printed the wheel wall mounts with a 0.6mm nozzle at 0.3mm layer heights with 5 perimeters in PLA.I've also printed the pedal mount with 5 perimeters 0.6mm nozzle and 0.3mm layer height with 60% grid infill, using colourfabb PLA/PHA filament.

Disclamer (Please be aware that the pedal dimensions are detrimental to the success of the mounting, please check that fitment is secure for you're bike.
I shall not be held responsible for any damage incurred by misuse or insufficient part strength caused by poor materials or inadequate slicing parameters)