UIScrollView setContentSize doesn't work

I have a really big problem with UIScrollView. To make sure it wasn't my actual project, I created a NEW project, iPhone only, for iOS 6 and 7. I disabled autolayout.

1. I created a Tab Bar project
2. I created a view controller, embedded it in a navigation controller and connected it as Tab bar item #0
3. I put a UIScrollView in my view.
4. I connected the scrollview in the custom UIViewController created for this view.
5. I synthesized my IBOutlet and set the delegate to self. I also implemented delegate in .h

Here is my code (ViewDidLoad):

    self.scrollView.delegate = self;
    [self.scrollView setScrollEnabled:YES];

    [self.scrollView setContentSize:CGSizeMake(self.view.frame.size.width, 20000)];


    NSLog(@"contentSize width %f", self.scrollView.contentSize.width);
    NSLog(@"contentSize height %f", self.scrollView.contentSize.height);

    NSLog(@"%@", NSStringFromCGAffineTransform(self.scrollView.transform));

It returns me "contentSize width 20000.000000", "contentSize height 0.000000 " and "[1, 0, 0, 1, 0, 0]". It scrolls left-right where it should scroll up-down

Please help!