As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) PILOT REPORTED AIRFRAME VIBRATION AFTER TAKEOFF, THAT DISSIPATED SHORTLY THEREAFTER. NOSE WHEEL REMOVED AND DISASSEMBLED. FOUND 1.75 OUNCE RUBBER BALANCE WEIGHT HAD COME LOOSE FROM INSIDE THE TIRE. THESE BALANCE WEIGHTS ARE INSTALLED AT TIME OF TIRE MFG. THIS HAS PREVIOUSLY OCCURRED WITH THESE TIRES.