Originally Posted by
tizeye
So people could write in Craigslist..."27" bike for sale, like new condition" which only illustrated that they hadn't a clue about sizing a bike.
This is a mis-application of a traditional sizing standard.
Back in the 1920s-1960s there was very little adult cycling in the USA. Most bikes were sold at hardware and automotive tire stores for
adolescents. The (upright riding position) bikes were sized by tire sizes: 16", 20", 24", 26".
Bikes at some big box stores are still sized in this way in 2010.