...bicycles (as well as uni and tri), motorcycles, skateboards, lawnmowers, wheelbarrows, non-digital watches and clocks, wheelchairs, ...I say wheels, depending on your definition. I mean, there are 5 wheels on an office chair, right? Now think of all the stools, chairs, shopping carts, golf carts, appliances with wheels...
BTW, it might be an interesting question but how in the world would this be a cause for an argument? Just my usual nitpicking.