None of the pet stores near us sell solid plastic wheels (I've checked 3; PJ's, Super Pet and Pet Smart). We have only seen solid metal wheels, and the skimpy plastic ones for hamsters that have wrungs which are too small.
The cage has a solid floor and wooden shelves. The only metal is the wheel.
Hmm..Maybe Petsupplyhouse has them.
Prevent a litter
Fix your critter