Our design engineer and GM, Paul Schulte answers this question. Paul is a member of the Team USA Men's Wheelchair Basketball Team. "I used to play in an Invacare® Top End® Schulte Signature Titanium Wheelchair (guess where that name came from) but changed to aluminum because I wanted to play in what most players can afford. Then I decided to redesign our aluminum version so that it was as light as titanium, yet perform even better. So the Invacare® Top End® Schulte 7000 Series Basketball Wheelchair does just that. It is build of 7005 material with many enhancements that maximizes performance by minimizing play in the front casters and rear wheels. Plus, it's easier to maintain.