Nope I had a black girlfriend. I heard it firsthand and myself “only” being 6 inches she found me quite nice. And before that I had a young black woman. she enjoyed what I have as well and kept coming back. It’s a porn thing, maybe a myth Only maybe, there could be a higher percentage of black men that have a big one within their rates compared to other races
BF of ex’s friend had a 9”. She didn’t really enjoy sex, it hurt every time. She put up with it thinking she would get used to it. She never did, her vagina not deep enough for him. No idea if he tried gentler and slower, or not fully in though. No idea if she stayed with him since I was gone, but you get the idea there are limits. I was turned down by two women who were initially interested in meeting me when they found out I have 6” and they could only take 5” even after I assured them I have good control and able to hold back from full insertion.
I've sucked a number of black cocks. Generally, they run just a tad bigger than white cocks. I've come across a few of both races that were quite large.
Having gone to spas where there are naked men and women, on average the black men had slightly bigger flaccid cocks. No idea about erect ones as I have never seen a black man's cock erect.