This is a remix from "Bike Disc Brake Protector" found on Pinshape (https://pinshape.com/items/22582-3d-printed-bike-disc-brake-protector) Designed by José Luis Garcia. I have copied it here for easy printing. His remarks are as follows:

Description
The design consists of 3 parts intended to protect your bike disc brake. The pieces are printed in PLA but you can print them in ABS.
You can use extension cords and longer screws to adapt it to other bikes and if it's necessary you can add a foam or rubber to fit all the pieces.
It's a simple design so you can modify it according your needs. I suggest you print the pieces in ABS first because it's a material more flexible and easy to handle.
If your bike doesn't have disc brake , you can use this design like a decorative element giving to your bike a racing appearance.
This design is the first prototype and you can improve it.
The print settings depend on your type of printer, I use Repetier-Host Slic3r SW. Config PLA.txt file is attached here. 

I've also added a version with a rotor shield. This one will likely need supports when printed as most of it is elevated.