Really great work. Not only are your constructions superb, capturing the illusion of solidity and form with considerable confidence and accuracy, but the spoke patterns and tire treads you tackled are of a considerable degree of complexity, and the care, patience and specificity with which you approached each one is definitely worthy of praise.

The one thing I'd push you towards - and all things considered, it may not be necessary with these wheels in isolation like this, but could start to be more necessary when you get into incorporating them into a more complex drawing where you need to be more focused on controlling your focal areas are opting to approach some of these elements more as texture than construction.

The main cases for this are the tire treads with a thicker, chunkier appearance - mainly 13 and 14 - where you did appear to get caught up in drawing the internal edges of each tread-chunk, and were visibly trying to avoid making them too eye-catching while still maintaining the volume and thickness of each piece. The solution to this would be to avoid drawing the internal details altogether, and instead opting for the techniques involving cast shadows explained back in lesson 2.

Here's an example of what I mean. Using cast shadows gives us far more control over which marks we actually put down without necessarily committing ourselves to constructing every single form that we wish to imply on our drawing.

Aside from that, your work really is phenomenal here, and I'm eager to see what you'll produce in the next lesson. I'll go ahead and mark this one as complete.