Miles are easy to quantify. Speed is easy to quantify. Elevation is easy to quantify. We need a similar measurement for fun.
Of the four, which one is most important? If we had a fun level unit, measureable on some kind of expensive electronic thingie so we could compare and lie about it, it would change the sport of bicycling forever.
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My greatest fear is all of my kids standing around my coffin and talking about "how sensible" dad was.