I bought these bearings to replace the bearings in aluminum bicycle hubs. I am building a supermileage vehicle and decided to try these bearings to minimize the rolling resistance. They far exceeded my expectations and were a fantastic upgrade from the steel bearings they replaced. An extra benefit that I found when using the ceramic bearings was the minimal thermal expansion. To remove them from the aluminum bicycle hub all I did was hit them with a hair drier and they nearly fell out.
Excelent Bearings 
