Ah, the beauty of the Internet..
I bought this Israeli poster purely (or impurely?) on the basis of the supple flesh on display, without an inkling as to what was the actual movie. Although the title in Hebrew reads “Race to Lust”, there was no such movie title listed anywhere. Shooting blindly, I posted this puzzle on a genre movie-poster collectors’ forum, and after about 6 hours got a reply. It’s a 1976 French adult film titled Porn’s Girls, featuring a dashing male lead who rides more than just motorbikes.