aborted takeoff

Cessna 172M @ KLOU. My first aborted takeoff. The first time it started to shake I applied back pressure and decided to proceed as shaking was common on landing. But as I reached 55 knots it was clear there was something wrong. I decided to abort and since I had plenty of runway left I just let the plane slowdown without breaking as I thought I had a flat tire and I didn't want to put it into the grass. Turns out the issue was a shimmy dampener failure. The school fixed it the next day and I flew it a few days later.