Generally, in sex and athleticism, yes. And that is what is so erotic (though only as a general rule, as some white and even a small handful of Asian men are more athletically and sexually endowed than the average black man). If society and technology were to break down and mankind wandered naked, ruled by instinct and lust, black men would much more often be the conquering alpha male to bring the female into heat.
I think evolution based on social conditions has even played a part in this. Historically, in European and Asian societies, the man has chosen who to mate with and has had greater control over women's sexuality than in African societies. And they've gotten their power due to status, rather than physical or sexual traits. While there has historically also been tribal leaders in African societies, and yes, men may have multiple wives, that does not mean that the African women have always mated with their lawful husbands. It's actually been documented by many anthropologists that in African tribal culture, many women have sex with mates outside of their marriage. And this has had a long history. Given also the fact that African societies generally wear less clothing, natural selection of the sexually fittest male has played a much larger role there. I know this is sounding pretty kinky, but there's some logic behind it also.
I see the black male's penis as plumage, like that of a peacock feather. The glistening dark shaft, often pink tip, greater length and thickness are all very visually erotic traits as well as an example of sexual dimorphism, much like how wider hips, milky skin, flush pink nipples and labia and larger breasts show more pronounced feminine traits of a white female.
Given that the women were historically more apt to choose their breeding mate in African societies, it also makes sense that African women would more often frequent a mate that gave them greater sexual pleasure. As a result of this, it makes sense that African males with thicker cocks, more sexual stamina and stronger instinctual sexual traits would be selected.
40,000 years of evolution is a bitch. Again, it's not that all black males have these traits. For that to occur, African women would have had to cut off sex with their husbands entirely, mating exclusively with their sexually preferred male. And that didn't happen. But their sexual practices made superior sexually adept black males a lot more common than males in other societies. Again, there are white males and occasionally asian males with good sexual traits also, but just like in American pro sports calling for physical power, when looking at the cream of the crop, there is a majority of fit black males. In a country where roughly than 10% of the men are black, that's a "coincidence" that cannot be ignored.
Superior race? Hell no. There are many more factors involved than the sexual and physical that involve success in a species with such complexity.
Sexually superior? Well, damn. As a general rule... it's hard to ignore the signs.