I have bent and twisted wheel supports. This was the condition they were in when I bought it. I don't know what caused it probably some rough riding (or possibly having to swerve real fast because some Kristi was stalled in the trail, Sorry Bob had to add that). I noticed on some pictures the trackmaster has a stiffener on the front set of wheels. Could this be done to all tandem sets or is there suppose to be some flex in them. Say, weld a length of angle iron along one side?