Magic is found in many places; liminal spaces, trinkets, most books and of course, within Every Person.
For some it is buried too deep to easily access, for others, cyclists in particular, they overflow with more than dimensional stability can handle.
For the Clestalia Cabal, it was a daily struggle to discreetly siphon off the excess magic from unsuspecting cyclists.
The whole process looked questionable but explaining it was worse.