Originally Posted by
ironhorse3
It is really awkward to ride a bike with overlarge frame, maybe unsafe especially if you're male and want to come to a stop off the saddle. You might impale yourself on the top bar. Jumping off and on the bike also seems a little uncool, and it's better to have a bike that fits you just right. It's like writing with a pen that skips -- you can do it but it's down right annoying.
I've seen a lot of people riding bikes with a standover that's a bit too high for them, and I've never heard a single story of them nutting themselves on the top tube. As long as it's not TOO big for you (a couple cm too big would fit you fine), and you can stand over it on tiptoes or whatever, you will probably be just fine if the saddle and bars are in the right positions.