I did a flight with my CFI today. Landing at 3W2 I encountered a fairly violent nose gear shimmy on rollout, it dissipated taxiing in. I though perhaps I’d hit and imperfection in the runway and didn’t give it a second thought. There was no abnormality in the subsequent takeoff, but I encountered the same shimmy on landing back at home base. Again once I slowed down it went away completely. The tire is fine and at 30 psi. I can’t see anything obviously wrong with the gear. Sound familiar?