I ran 7/6 with no rear bar and it was good. 7/5 is a popular alternative for those that opt for more rear roll stiffness.

I run 7/6 with a 7/8" front bar on full stiff and stock rear. It's beautiful on the street.

without a rear bar, on my chassis, sucks balls; it plows and cant turn.

maybe on your non-donkey-dick NB chassis that's okay.