As Diana Ross put it, "can it be that life was so simple then, or has time rewritten every line?" I mean, I like looking at an attractive woman as much as (OK, more than) the next man, but even my 17 year old self could see these ads were Very Wrong. It's not as if she's getting on the bike dressed like that, is it? If you wanted porn way back then, you took a deep breath, reached for the top shelf and accepted your humiliation like a man.
Then through the 1980s we got serious, and true artists like Bob Carlos Clarke found it all a bit hard to take. The caring sharing ninties meant this sort of stuff was bound for the history books, and poor Bob Carlos Clarke took his own life in 2006. Lord knows what he'd make of the Nuts generation.
(Thanks to Bevel Heaven for saving me the trouble of digging out an old Bike magazine and scanning a pic)