I got a wheel for my boys. I got the large plastic one because of what I read about the wire ones hurting their tails. Last night suddenly the wheel was silent. I looked over and the wheel was off of the peg and on the floor. This morning I put it back on the peg and they were off and running. But it only last a few minutes and the wheel was on the floor again. My hubby says he can fix it, but not today. Now all four of them are staring at me like it's my fault!