Okay, I'll be one of those guys who post "I only rode [something] miles, but it was [some way]."
Only
14-ish miles, but it was
rolling hills, and I averaged nearly 20 mph
on fixed gear.
Here's the elevation profile:
As you can probably guess, I was riding in circles (10 laps around a 1.38 mile course).
But Broctoon, why would you ride at a place like that? You didn't even go anywhere!
I do it for an interval workout, and get a heart rate graph like this:
Finally, this is my favorite one. The speed graph. I'll just note that the peaks definitely come when I'm on one of the two descents of this course, but the troughs don't necessarily coincide with the two climbs, as I like to sprint up hills as hard as I can.
This workout is very strenuous and very fun. It doesn't hurt that lots of pretty girls like to walk and jog this course.
I'm always trying to beat my previous best lap time or best overall time for 10 laps. One thing that occurs to me (should be obvious, but may not be) is that average speed doesn't mean much. I can do a tempo workout, 20 + or - 2 mph on level ground for about 60 minutes, and not be nearly as exhausted as I get after riding this 42 minute workout, which was 19.6 mph average speed, but fluctuating from about 14 to 32 mph. There are 20 cycles of climb-flat-descend, and my poor little ticker never knows what's coming next! Fixed gear bike is a deliberate choice for this workout, because it allows no cheating. It requires or at least encourages me to push as hard as I can up hills and spin a very fast cadence down them. Also, there is of course no coasting, ever.