[Walt Fricke]

Max

You mean the I beam (like Pauter?) is stiffer in the rotation axis for its weight than the H beam (e.g., Carillo)? And what is a stock rod? Or do I have these mixed up?

How does "area" MOI differ from MOI.

If you will forgive that question from a non-engineer.

MOI seems difficult to calculate for other than simple disks. I once asked one of my ME buddies if there were a simple way to just measure MOI rather than try to calculate it for complicated shapes. He didn't know off hand, though we agreed that for something which just rotates you could wind a string around it, put a weight on the string, and see how long it took for this or that (say one revolution, or X drop of the weight) to happen, fudge for friction, and get a number.

For rods there is MOI and reciprocating weight as well. Even more complex calculation for MOI?

Or is it half-way simple, like rod big end weight contributes to the MOI of the crank? And the rod doesn't really have a separate MOI?

If Pauter is neither H nor I, but X or something, this leads to the question of why they chose that design. It is said that the Pauter has less windage. They obviously are strong enough for the job, and light enough (until you get into titanium), and because they cost less than the Carillo (maybe Carillo clones have arrived and are as good?) a lot of us have purchased them. And Pauter has engineering skills.

But how they are strong enough for their size (and especially weight) in radial plane bending, where they are thin compared to both stock and Carillo styles, is something I've not seen explained.

At least to my satisfaction. That's a slippery concept since I don't have the training to understand this stuff in depth (pun intended). But the concept that the deeper the beam the stronger it is in bending (in that plane) seems understandable enough, and I've seen it in action when I built my house, which was my introduction to such concepts.