Tuesday 4th February 1913

A US patent for a “demountable tire-carrying rim”, was issued to Louis Henry Perlman of New York City. This was the first automobile tire rim designed to be removed and remounted. His demountable tires (patent No. 1,052,270) worked pretty much like the ones on your car right now. A bead — that’s the inner rim of the tire — held the tire against a groove machined into the wheel. The friction of shallow notches kept the tire from rotating on the wheel, though some early applications used a cumbersome screw-clamp system. The only downside was the tire-and-wheel assembly had to be balanced to prevent vibrations and ensure a smooth ride, but that wasn’t a big problem. Today no one thinks twice about it (except when they forget to get it done). Perlman’s invention led to the adoption of pneumatic (inflated) tires, which provide much better performance. It also allowed automobile owners to choose their own wheels, which is one of the most common ways of customizing one’s ride.