Top Thrill Dragster wheel 9-3-07

Great Job TTD 2007 Crew,The Best CrewYet :-),Hope It Breaks The Record.

http://www.kiextreme.com/gallery/displayimage.php?pos=-3630

Bad wheels XD

Polyurethane coaster wheels work great, but they have a problem. Polyurethane is an excellent insulator. As the wheels turn, heat builds up in the bearings and gets transferred through the metal wheel into the inner edge of the tire. The weight of the train causes the tire to deform, and as the tire flexes, even more heat builds up in the tire itself. Ultimately this causes the center core of the tire to actually melt, and eventually this molten plastic can either go shooting through the surface of the tire, or squirt out along the seam between the tire and the wheel. The result is a "blow out". Less common is a delamination between the tire and wheel. When does it happen? Depends on the ride, and the wheel position on the train.

Several companies rehabilitate coaster wheels. Usually the wheel goes out for overhaul, meaning it gets new bearings, it gets refinished, and it gets a new tire.

A leading company for this is Uremet, and much of the detail above about wheel failures is based on their wheel maintenance class.

--Dave Althoff, Jr.

Once again, Dave answers all my questions. I figured someone must remanufacture coaster wheels. I had no idea polyurethane wheels can "blow out", though.