My input; these bearings are quite sensitive to any contamination. They are used quite a lot in bicycles (high-end stuff) but require frequent maintenance and replacement. The sealed ball bearings in your bike are of excellent quality and will give very good service for years. If you want to play around with this by all means, but realize the trade-off in slightly less friction is offset by a much less robust bearing overall. This application is for machines that can be serviced frequently and fairly easily (pumps, bicycles, and so on), not for vehicles like motorcycles that are ridden for years and need to be reliable under a wide variety of conditions (dirt, dust, water, snow, hard usage).
I appreciate the input. But, they make ceramic wheel bearings specifically for motorcycles I believe.