ERJ Captain reported a stabilizer trim problem during First Officer's takeoff. Crew diverted and made a precautionary landing.

Narrative

On take off from ZZZ1 I was PM and FO was PF. After clean up FO started complaining that the aircraft didn't feel right and he thought the trim was not working. We attempted to move the CA side trim and backup pedestal trim; all of which gave me good indications on the EICAS. He still stated it felt like it was not trim and possibly moving in reverse and suggested we divert to ZZZ. At that time I evaluated the seriousness of the situation and determined a precautionary landing at ZZZ is our best option. The integrity of the plane was in question and the outcome of the flight would be uncertain to continue. We ran pitch trim Runway QRC as we had no EICAS indications. After deactivating System 1 and manually trimming from CA trim switch we were able to get him feeling more comfortable. While trimming and controlling the aircraft a maximum speed of 261 was reached below 10;000ft. [We advised ATC] per the Trim Runaway QRC because I was unsure if the situation would improve. Landing speeds were attained through ACARS for ZZZ and briefly flashed max landing weight exceeded on the scratch pad. I don't believe we were overweight on the landing but I considered burning fuel but decided against it because the nature of the flight and getting the aircraft on the ground was a priority. The autopilot was never engaged and after the cutout buttons were pressed we began to get EICAS messages. A visual to ZZZ XXL was chosen to maximize Runway available as it may float more out of trim. CFR was rolled just as a precaution; no brace was give to passengers. Coordination with Dispatch was accomplished through ACARS and FA (Flight Attendant) address through specific button. Lastly passengers were given an announcement on the diversion to ZZZ. In the process or coordinating the diversion I believe I missed reading the Descent checklist but all steps were performed and landing checklist was performed after final configuration per normal SOP. After touchdown; it was uneventful to the gate. The fire department followed us to the gate and verified our brakes were not at risk of ignition; indications were normal. The FO was very concerned over the control of the aircraft and in any scenario it would be best to address the concern and land. I could not in good conscience continue the flight unsure of my aircraft.