"I've received the hybrid bearings I ordered. (SR8C-YZZ NB2) I talked to "Mike" about a recommendation for bearings to use in an 'Adult soap box derby' car. He showed interest & knowledge---something I've had trouble finding for this subject. I think these bearings are going to really help me get down the hill faster. I will be calling him again for advice on 'breaking in' these bearings.