Hubcentric wheel spacers Kits. Motorbike MX Tyres. Bolts and Inserts are 14x1.5. These are precision fit 30mm Hubcentric wheel spacers, In this kit you get 2 spacers and 10 Short Head bolts. These are easy to fit, simply remove your wheel fit the spacers onto the hub (make sure nothing is fowling it onto the hub) and refit the wheel with the longer bolts.