I have not owned a CRG, but doubt that bearing cassettes, the aluminum blocks that hold the bearings in place, would be worn on a 2013 chassis. The bearing should fit tightly in the cassette. The bearing should not move in the cassette. The only side-to-side movement should be the inside race that goes around the axle. You might have to use a very fine sand paper to clean up the inside of the cassette before installing the new bearing. You should be able to replace the bearings many times without thinking about replacing the cassettes. Think I’ve put a dozen bearings into my current cassettes without a problem.
If the bearing does move within the cassette, there is a possibility that someone not knowing how a bearing goes into a cassette could have damaged it or you have the wrong size bearing.
LAD Specialties / tony kart / rotax / kt100