Stan Wagon, a mathematician at Macalester College in St. Paul, Minn., has a
bicycle with square wheels. It’s a weird contraption, but he can ride it
perfectly smoothly. His secret is the shape of the road over which the wheels
For those of you who might feel this blog neglects geometry, and the inverted catenary in particular.
Quibble: that looks like a tricycle to me — there’s a basket in between two back wheels.