My brace varies by bow and shafting .
Im pulling 50 @ 29″ on most of mine and they like a 2016 ,30.5″ with 125 head or a 2018 @ 29.5 with 200 [ plus insert ]
my 40# 66″er that i just got for target and 3d likes a 1916 , full length with125
the 1916 and 2018 both run at about 12 gpp out of the respective bows
2117 sound way over spined for me – but i always end up lighter spine than most people