Bakuon!! is fun. It's a lot of fun. I'm afraid that unlike the last commentator I'm not Sophisticated and Mature enough of an unvirgin (lol), to dislike this manga.
To call this K-On with bikes isn't a slur, in fact it's how this manga is actually advertised (unlike the original k-on manga however, this isn't a 4koma). The girls are hilarious, the plot is largely episodic and Larry David'ish (no lessons learned), and the level of motorcycle knowledge and trivia displayed would make the editorial board of Cycle World applaud. Seriously, I have no clue why the other guy says "I actually have a motorcycle license and am interested in a proper series about the scene", as the manga is larded with bike culture references. It's almost like he hasn't gasp actually read the manga.
To sum up if you like bike trivia and culture, cute-girls-doing-stupid-things, and zany, lowbrow, madcap humour, then give this a shot.
Just a post script of sorts, the other commentator accused Orimoto of drawing naughty manga in the past, that's true. So have the mangaka of Yotsuba&, Ghost in the Shell, Black Lagoon, Shokugeki no Soma, Medaka Box, Negima, Gunslinger Girl, Tenchi Muyo, Bastard, Keroro Gunsou and Yokohama Kaidashi Kikō. Plus hundreds more.
So what's the point? Who knows? ask him.