The Formula Mazda wheel centers are made from an aluminum and magnesium alloy. In addition to being very light in weight, the drive pins holes are also susceptible to wear and tear. The hub's steel drive pins can cause the wheel center's drive pin holes to become slightly oblong. After they become oblong, or egg-shaped, they wheels tend to move ever so slightly under braking and acceleration, but especially under braking. The resulting movement can then loosen the axle nuts on the left side of the car (the FM has right hand threads on the left side). To help solve that problem, and to extend the life of the wheel centers, it's possible to machine the drive pin holes and press steel inserts into the enlarged holes. Special thanks to Moses Smith Racing for supplying parts and lots of good advice, and for helping to keep Formula Mazda alive and well.