Well, I definitely don't carry a hammer with me on my bike. The instantaneous force I'm referring to is when I grab the bars, push hard with my legs, and put all of my back muscles into it. I'm pushing with a nearly straight leg and pulling MUCH more than a measly 10% of my bodyweight. More like 50%+. That may only be for part of a downstroke and it is applied rapidly as opposed to a sine function of a single leg levering between a seat and a pedal. If you can exceed that by doing deep-knee bends, then you are definitely outside the norm.