Rivets two part hub.
Must be cheaper manufacture than solid, or slightly different properties.
No rust are the hubs aluminium, i would have thought dissimilar corrosion.
Reduce weight i suppose.
Composite disc
The aluminium hat, which provides benefits in terms of weight and performance, is connected to the brake surface in special cast iron by steel pins.
Composite disc
The aluminium hat, which provides benefits in terms of weight and performance, is connected to the brake surface in special cast iron by steel pins.