I appreciate this question has been answered but it hasn’t been answered in a way that makes sense to me. Kindly don’t point me to a lesson on this because I have read the lessons already.
Based on the lessons I have read, neuf and neuve means never been used. Subsequently, if I say ‘I have bought a new bike’, in English it means I have bought a brand-new bike. If the intention was to say I have bought a bike new to me but not brand new, then the sentence should refer to it being secondhand bike.
Looking at all the discussions below, it seems to me the sentence should be altered so there is no confusion about whether we are talking about a bike that is new to a person or a brand-new bike that has never been used.