Just when you think you've seen about everything.... On my commute home today I came upon a young man riding a Schwinn LeTour (I'm guessing late 1970s vintage, in that great yellow color they had then) with a fully inflated basketball jammed between the down tube and top tube near the head tube. I asked about the fit, and here was his reply. "Man, you got to have a flat traditional top tube to pull this off. I got two other bikes, but both have sloping top tubes and the basketball just won't fit." I asked if it fit other flat top tube bikes. We pulled over and tried it on my Cannondale 800T. Fit just fine. So, if you have a basketball to transport and no racks, you can't get by with a sloping top tube. Live and learn.