My name is Alex and I'm from Simi Valley In California. I have a 60 dollar magna that I got from target and the chain decided to derail from the sprocket, pull down the tensioner, and the tensioner would go into the spokes. did it a few times after 20 minutes of awesome riding. Now the tensioner won't stay put, the chain keeps derailing to the inside, and my wheel is shredded. I need new parts for my bike... I need to either find a better tensioner that grips the frame like ****, or eliminate the tensioner and take a risk on the chain size not working out. I need a new rear wheel... but I have no idea how to find an exact match for what I need. I am in desperation. Can anyone help?