I have an electric road bike that has SM-RT64 Shimano centerlock brake rotor in the front. I have noticed that when I press the front brake and try to rock the bike back and forth, there's some free play somewhere in the braking system.
I checked for free play in the headset to find nothing.
I checked hub (HB-R7070) bearings for looseness but they weren't loose.
I checked that the disc brakes have the pad retaining screw tight.
When I rock the bike back and forth, it doesn't seem to be the brake pads that are loose. The looseness seems to be at the centerlock brake rotor. It is not the fixed rivets connecting the spider to the disc that are free; instead, the brake disc seems to be rocking back and forth at the hub, and the lockring seems to be rocking along with it. Thus, the brake disc - hub connection is of suspect.
Related information found online:
What could be the cause?
Is the brake disc defective?
Are the aluminum centerlock splines in the hub damaged? (I hope not as it took about 5 hours to build the front wheel, and swapping the hub to another would take another 5 hours).
Or is the centerlock design just too weak for the massive braking forces I need (my weight is over 100kg)?