Bean wrote:Only the case when a person is standing perfectly still,
Your use of "dV" suggests that you're trying to sound smart by throwing out variable names without knowing what they actually mean
Meanwhile, 30psi in a bike tire is 30psi. A fatbike can go as low as single-digit air pressure.
But why are we (you) talking about outliers rather than the vast majority of trail users? I'm not bringing up equestrians going out in to muddy areas and doing more trail damage than a bulldozer could, or hikers substantially widening sections of trail in an effort to avoid a little bit of mud (whoops).
Simple test would be ride a bike across a flat stretch of sand or snow at a steady speed and also hike it on a parallel path a few feet off, then compare. The deeper the depression, the greater the PSI exerted on the terrain.Delta v
is at the basic level of even a Physics I high school class as it's used to calculate a
) then multiplied through m
to yield F
Regarding tire pressure versus ground force (P.S.I.), I would be interested to see your free body diagram of the two, especially as your line of logic regarding "30psi" and single digit fatbike tire pressures leads to interesting
conclusions of the weightless nature of a bike+rider if he drops his tire pressure to 0psi, much less if you created a relative vacuum by dropping it below 1atm (or its 14k' equivalent).
The ripples do illustrate the force exerted in a highly detectable way unlike loose surfaces where the top layer is redistributed in a more even fashion obfuscating the detection of soil/terrain displacement by keeping it below the JND on a pass-by-pass basis.
I think you're confusing "outlier" with "negligible" as even outliers can be impactful to the overall data set, i.e. a component. I could point out the rhetorical and or logical fallacies of the other part but do not think you would be interested nor that it would have any lasting benefit here.
You seem to want to rely solely on (your) experience, but when accounts of experience on an objective matter differ, do you prefer to settle it with rhetorical devices or a synthesis of rationalism and empiricism (i.e. science; physics)?
pw wrote:I think this stuff also happens in spring when water from snow melt flows down the trail and people walk next to the trail to avoid getting wet.
Yes, but not just snow melt, but any precip'. On Uncompahgre, there were several muddy low points (which the monsoons would highlight) that we rocked in to stabilize the trail and make it possible to keep your feet dry by staying in-trail (removing the impetus to blaze a new one). Our main project was breaking up a straight downhill section into steps (with backfill and crush) which it seems is what that section on Elbert needs as well as rocking in the extra six trails (either to slow erosion, dissuade use, or help return to nature). Switchbacks would help too, but I can see folks cutting them and re-establishing a straight line just as I've seen others hiking over log barricades to take switchback cutoffs.