A thin brass shim will wedge into the space and fill it so the race does not move. Find a place where you can get a small piece of the brass (it won't be cheap) like Micheal's or Hobby Lobby. Then cut it to the right diameter/circumference of the steering tube and place it on the tube so it rests on the race holding ledge at the point of contact with the crown of the fork. Then using s race setting tool, drive the race in place. The brass will mold to the correct position to hold the race centered on the fork. HTH Smiles, MH