We put these wheels on a 10 year old scooter that still had original wheels.  The scooter is not a Razor, it is a Fisher-Price scooter that used to have "trainIng wheels" in back.  Anyway, the 110mm wheels bolted right in place.  The bearings that come with the wheels are ABEC 5's.  The wheels roll very smoothly.  The boys are very happy with the revamped scooter.  These wheels are a great tune-up item.