A Bike That Goes Nowhere

My dad put this bike that goes nowhere near the window.  He goes on the bike for a few minutes and then says, "Whew, that was a workout!" 

The funny thing is that he's pedaling with all of his might, but he doesn't move at all. 


We have another bike that's in the garage and he rides that outside and I get to run next to him on the street.  That bike is fun! 

But this bike, it doesn't go anywhere.  I stare at him when he's pedaling and I wait and I wait, but it doesn't move an inch.  This bike is no fun.