While floating brake rotors are more commonly found on sportbikes, they’re starting to become more popular on cruisers too. Several technologically advanced cruisers use them, and they’re a very popular aftermarket conversion.
Normally, floating rotors are trouble-free and need no special care. But lately I’ve seen a few—not many, but enough to catch my attention—that have stopped floating. What happens is that the little buttons that hold the rotor to the hub become rusty and crusty, more so on bikes that have seen a lot of rough weather and have high miles on them. In some cases one or more of the buttons will have actually seized. Once that happens, the rotor will mimic one that’s out of true. The first sign may be a brake lever that has too much travel because the high side of the rotor knocks the pad too far back into the caliper, or it may pick up a pulse as the rotor wobbles back and forth.
Fortunately the fix is simple. Before you condemn the rotor, make sure the buttons move freely. If they don’t, remove the brake rotor from the wheel. On the backside of the button will be an e-clip, and most likely a spring/shim. Remove the clip and shim, and the button should pop right out. You can clean them up with a wire brush or sandpaper. Reinstall them dry, and preferably with a new e-clip.