The breeder I got my two bengal girls from, here in Alabama, has one of the "millwood" style cat wheels IN HER LIVING ROOM !!! When I visited her, and chose my kittens, I was witness to the cats (at the time, mostly kittens approx. 6 months old) using the wheel quite successfully.
If you'd like, I can contact her, and ask pertinent questions -- like WHERE did you get it, how much did it cost. etc. I'll write her an e-mail, and ask if she can fill me in on the details.
It looked VERY STURDY. the frame was made of approx. 2" diameter pipe, with "elbows at the "bends, the whole "wheel appeared to be made of metal, and the "running surface" was covered with some type of durable looking indoor/outdoor carpet.
I may STILL break down and buy one -- if I can just figure out WHERE I could PUT it.
LaVon
"fancidots"