Originally Posted by reppans

I completely agree WRT an overall loop ride on asphalt. No one is arguing that there is a more efficient mode of human-powered transport than a bicycle. However, the general point was made (and I am paraphrasing) that on a steep grade, at some point, a bicycle's mechanical advantage will be more than offset by it's own weight disadvantage. For some reason, this valid comment ensued into a one-sided dog pile as if the bicycle were always able to retain a net mechanical advantage up any hill.

So, while I might a agree with Doug's specific example - hike 35lbs vs bike ~65 up a 6% grade - and prefer the bicycle as well, I think the efficiency (i.e., effort/energy) analysis vs walking is going to be a whole lot closer than a layman's extrapolation of his uphill 2x pace.

For my personal case - hike 20 lbs vs bike 50, I have absolutely thought about how much easier it would be to hike up some grades. I can now guesstimate my cross-over point to prefer hiking 20 lbs might be a 7-8% grade. This is based the empirical finish times of the 5th place females - who are certainly fitter than I, and I'd bet most of us here - with their run 0 lbs vs bike ~20 lbs time equilibriums on an ~10% extrapolated grade (i.e., runner beats cyclist by ~10% on an 11% grade, so should be ~even on a 10% grade).