Thanks for all of the feedback, y’all! As it happens, I’ve finally gotten around listening to some of the members-only podcasts that EC posts. In the very first members-only Geek Warning, there’s a good discussion about this (well, close enough) topic (Ask a Wrench Bonus Episode, 11/9/2023, at the end of the episode). Many of the same points were raised and many of the same solutions were mentioned. We’re in good company! Definitely worth a listen for those invested in this topic. Thanks again!
As a follow up, I recently checked the CAAD12 fork steerer with the bonded Zinn insert. By tapping, it appears to be no longer bonded around the full circumference, from 1cm above the base of the stem, to 2cm below - where the upper spacer is. The pattern is symmetrical. I suspect this is due to flex. I’m not too worried about this as it’s still supported internally but the slight ring barking from the lower bearing is a problem.
Super interesting – I was wondering about the differential flex of this system. I love that you’ve followed up with both an analysis and a, annotated picture, though I supposed I should’ve expected nothing less from this crew. Thanks Robert!