Why? Ceramic balls require careful maintenance, they easily disintegrate if they are not greased properly, and with the correct formula grease. Unless you are a serious racer, or a real weight weenie, they are just spending money so you can say you have ceramic bearings. Other things will bring more return for what you will spend on the ceramic items.

Besides which bearings, which bike are you doing this to (Fiori model and year,) so the correct size can be recommended.

Welcome to the Forum.

Bill