good sir, whats the threshhold of "unsafe" for the ratio of steer tube:empty space in the stem? the 722 headtube is longer so my steerer might some up short by about 15mm from my previous setup and i was thinking of testing it out with my current fork, but if thats too much i wont bother taking it all apart

i had asked this already but i think it got lost a couple pages ago, pls dont beat me.