I-Wave disc brake rotor Rohloff®

Outer rim too flexy

The rotor rim tends to deform too easily under normal braking forces. As a result, it is very hard to eliminate brake rub (i.e., once fixed, it comes back after the next ride). This may be due to the the rim being supported by only 4 thin "arms" while similar rotors from other brands (Magura, Hope, etc,) have 6 or more arms.