This was another pretty easy one. I'm not 100% happy with how the pedal turning looks with the feet anchored to them, but I suppose I can always fine-tune it down the track. My main beef is that the prac has us counter-rotate the pedals so they stay completely level as the parent wheel rotates... this is a 'close-enough' solution for our purposes, but in practice that's not how pedals sit as one rides a bike or unicycle. What actually happens is the pedals rotate slightly forward and back in a sinusoidal manner, responding to the rider's shifts in weight.
During the part about determining the radius of the traversed circle based on tyre diameter, we were told to create polygonal objects at the location of the centrePivot and wheel axis, and re-size them to determine their radii. The IT guy inside me was screaming "surely there is a better way to do this - there must be a tool of some sort!". Sure enough, a quick google would yield the Distance Tool (Create > Measure Tools > Distance Tool). It places two distance measurement nodes in your scene, which cause a connecting line and distance value overlay to be drawn in the viewports:
The cool thing about that is by parenting them to the relevant parts of the scene, you can move things around and see the distance change in real-time - this includes during animations!