I see the general advice is that longer bars require more power... that you're better off with a shorter bar if you mostly just cut small stuff.
Why is this?
If you are cutting through, say, 8" oak, will a 20" bar cut slower than a 16" bar? Why? Just the extra friction from the longer chain? I can't imagine chain friction on the unloaded part of the bar is really significant.
Or is the idea that longer bars need more power because a fully sunk longer bar is cutting more wood? Like my 210 can only really cut 16" of wood at a time, so if I had a 20" bar on it, it would be pointless because it would bog hopelessly in anything bigger than 16".
I guess my question is, so long as you are cutting smaller diameter wood, how much does excess bar length hurt you? And why?