Trakhak

Not surprised you've never had issues with those bolts. From what I've seen of your posts, you're clearly someone who knows how to respect the materials you're working with and treats them accordingly.

I knew only a couple of guys who used Cinelli stems with the aluminum stem bolt. One of the two was on a ride when the bolt snapped---without warning, of course. He managed to stay upright long enough to come to a safe stop, to his own surprise.

Among earlier generations of (European) pros, proper use of aluminum bolts might have been common knowledge, especially for the team mechanics.

bulgie 

Not great at riding no-hands, was he? Below a certain speed that gets difficult, but I bet I could coast to a stop with just grabbing the headset locknut with my hand. Hmm, have to try that to confirm. Level of difficulty might depend on frame geometry, specifically the tendency for wheel flop, which varies with head angle (mostly) and some other factors like fork offset. My personal bikes tend to have low-flop designs because I like steepish head angles.

I used to do a no-hands track stand pretty well, but I always steererd with the bars until stopped, then sat up to do the no-hands thing. Coming to a stop without handlebars might be tricky.

Phil Anderson told the story of a pro who pulled his stem clean out of the steerer, in the middle of a tightly-packed pro peloton. Nobody fell down! I think he attributed the stem coming out to the cone having been tightened too low in a small frame, into the taper where the butt begins. Then any little slippage causes the stem to become completely loose. Not from the bolt breaking.

EDIT: Ah I see you edited yours, the guy did not fall over, so I take back what I said about him not being good at riding no hands!

Mark B

Trakhak

Yes, I did Pat a disservice---I realized that I had conflated his story with that of another guy who overlapped a wheel on a two-man training ride way out of town, veered off the road, and managed to hit one of the few obstacles in sight: a telephone pole.

dddd

Interesting post, ...to me anyway. I do no-handed track-stands regularly these days. I was doing regular track-stands for many years and one day a fellow rider asked if I could do it no-handed, and just like that I did. Sometimes I use my knee to keep the bars from self-steering inward.

Also interesting in that I once bought a very small-framed Schwinn Circuit and, yep, had the stem quill pull out of the steer tube's internal butt taper while accelerating from a stop light (previous owner had very crudely tapered the bottom of the Cinelli stem quill to drive it in a little lower, ...great idea, ...NOT.
I profitably flipped that Schwinn Circuit twice, about ten years apart (small world and all that).

Bad Lag

What torque value do you use? Does it vary by brand?

I check for tightness as part of my maintenance. I do not re-torque, as such, just make sure the bolts are not loose.