measurements in inches: 2 - .250 x .625 x .4724 bearings (Crown Bolt 65628) I used these bearings: http://www.homedepot.com/p/Unbranded-0-250-in-x-0-625-in-Precision-Bearing-and-Reducer-65628/203537336 1 - 1/4" x 6" bolt 2 - 1/4" nylon lock nuts (nyloc) 2 - 1/4" fender washers