Deepl renders it as Fahrradrad.
Beolingus tells me it's Fahrradlaufrad.
Leo seems to recognize neither of these as a word.
Gmail in Chrome wants to correct it to Fahrrad Rad.
German Wikipedia has an entry for Fahrrad-Rad, a kinetic artwork of Duchamp.
Who's right? (Or is it none of the above?)
Edit: Context written by the OP as a comment:
It's from an e-mail to the Basel city government thanking them for looking into a temporary bike path issue (where the barriers were jostled out of place, narrowing the path) and telling them that it was pleasant to see the wheels of city government turning so quickly, and thus keeping my bicycle wheels turning quickly as well.