How do you know when a mountain bike is too small?

Question

I'm getting into mountain biking and have been looking around, although I really don't know how to tell if it's too small? I fit an 18" or 19" frame very nicely, but how do I know when I'm just too small for the bike?

Answer 1

You should be able to stand over the top tube without touching.

Answer 2

When you have raised the seat as much as you can and you knees are still hitting the handle bars.

Answer 3

Its too small when you climb & cant stretch your torso out to spread the weight. And if you're sitting upright when riding flats. And, tho' you should be able to straddle over the top bat, not when your on the seat  & your leg should almost, but not quite fully extend on the down stroke.

Answer 4

When the local circus clowns ask to borrow your bike for the next performance.