I made this thing for my bike (proper bike, not those ones you have to push around and pedal 8)

'Lock reminders' are usually ugly spring cords which you have to attach to the disc lock and brake lever to remain you to remove it before before flying ;)

This one looks a lot better. You can put it on the key barrel, so there is no way you won't notice.

I've included a small holder to attach it to you key chain.

Printed with Ninja-flex in two colors (pausing the print before the last layers), but should work with any kind of filament (ABS,PLA)