Re: 1963 Sportwin O-Ring on Upper Crank Bearing? Home › Forum › Ask A Member › 1963 Sportwin O-Ring on Upper Crank Bearing? › Re: 1963 Sportwin O-Ring on Upper Crank Bearing? chris-pReplies: 2456Topics: 153 December 23, 2017 at 8:07 pm #68924 Yes the bearings lock into position. The crank halves will not close if everything in not lined up.