Frame not suitable for 70" fixed gear?

But, going full circle, that still leaves going up hills as a problem. I think most people have trouble spinning a 70" gear up 10%+ hills. I know I have to resort to 25rpm and wrenching on the bars for that full upper body workout. If you've got gears you can change down and spin. If there's any flex in the BB then fixed and hills will find it.

Point 1: You can be pedaling at 50rpm and still be smooth with your power delivery.

Point 2: For a given gear ratio, power, cadence, and speed are linked. You can either produce the power to go up the hill at a certain speed or you can't - just because you're going slow doesn't mean you're pushing harder (in terms of torque) on the pedals. In fact it's the opposite, the person going faster (and necessarily at a higher cadence is pushing harder) because they've got to generate extra power to overcome speed-dependent losses (aero, rolling resistance, etc.).

Do the sums if you're feeling inclined! Essentially, because most of the power is dependent on rpm (the speed at which you go uphill) and torque is dependent on (1/rpm), rpm cancels out.

Courant