When you have the world’s most successful sneaker, why mess with it?

For almost 100 years, Converse, maker of the Chuck Taylor All Star, that flat-footed, star-sided, toe-capped flexible number beloved by everyone from Rihanna to Michelle Obama, Lil Wayne to the Jonas Brothers, did not. On Thursday, however, it did the previously unthinkable: change the Chuck.

O.M.G.! O.M.G.! The sky is falling.

O.K., not really. But still — daring to tweak an icon is always a dangerous move.

Just consider the branding controversies surrounding New Coke, or even Saint Laurent, which got into trouble when it dropped the “Yves” from the name of the ready-to-wear line. And even though the Chuck Taylor All Star II looks, to the naked eye, not that different from the original Chuck Taylor, it does involve 16 alterations, most focusing on the addition of Nike technology. (Nike has owned Converse since 2003.) Also, “more premium canvas.”

So what explains the sudden strategic switcheroo?

Interestingly enough, the same thing that caused Levi’s this month to unveil the most comprehensive rethink of its classic women’s jeans in 80 years. In a word, “comfort.”