I'm guessing you're talking mainly about the outer richmond, outer sunset, and maybe the excelsior? There are a few truly suburban-ish spots in the hilly parts in the middle of the city (like Monterey Heights, for instance), but I don't think those are very extensive.
This might not be completely fair, since I'm taking all of antioch whereas I'm doing SF in a neighborhood-by-neighborhood way... but all in all, I just don't think you can call any part of san francisco "suburban sprawl" without stretching the term beyond what people typically mean when they say it.
Population density of the outer sunset is: 16,489
Monterey heights: 9,639
btw, I'm getting these from
http://www.city-data.com/neighborhood/Monterey-Heights-San-F...
Now let's take a really sprawly place
http://en.wikipedia.org/wiki/Antioch,_California
about 3,500/sq mi
This might not be completely fair, since I'm taking all of antioch whereas I'm doing SF in a neighborhood-by-neighborhood way... but all in all, I just don't think you can call any part of san francisco "suburban sprawl" without stretching the term beyond what people typically mean when they say it.