[ishmandoo]

I couldn't figure this out at the time, but a potential explanation seems obvious to me now.

I think this may have been because the wheel starts accelerating from a particular point. To optimize distance traveled, it's better to have more acceleration up front. Shorter spokes means more acceleration. For the overall wheel, the spoke length is normalized, but it makes sense that the optimization would set the starting spoke shorter.

I should randomize the starting angle of the wheel and see if that fixes it.

I'm surprised to see that I didn't discuss this in the blog post. You're right, I should have.