Lol!
I wonder what Colorado statute requires bicycles be equipped with a speedometer & then defines the accuracy of the installed speedometer.
On a Federal level, (only because I have a CDL) commercial vehicles are required to have a speedometer installed and it's accuracy is required to be within 6 miles per hour at 60. So if you were wondering why no one ever gets a ticket for only going 5 over, now you know. 5 over could still yield a legal under indication as defined by law.
Denver is going to have a tough go with the retro-fit legislation and the redefining of bike path/park paths as "roadways," for the "legal rights & responsibilities" clause of the driving code to apply. But whatever...
Good luck with that.