I understand the premise of the steeper seat tube angle saving the hamstrings for the run. Is this only crucial in the 1/2 and full IM distances. If races are 20 - 40km rides followed by 5-12km runs and you condition appropriately will you still benefit as much from the steeper angle? I remember watching Olympic distance races on Television a couple of years ago the bikes all looked like coventional rd bikes with very short “U” shaped aero bars.
“all looked like coventional rd bikes with very short “U” shaped aero bars.”
They are, because of the drafting.
There is no rule for this. It varies from individual to individual. I run better off a steep angle but my wife can run just as good off either. In theory both steep and ultra slack “big slam” positions are supposed to save the hamstrings for the run, but all ITU Olympic length pros ride regular road bikes and seem to have no trouble running the 10 kms in fast times.