Re: Unicycling Theory


icon wrote:

Now, my wheel is 26" and my crank 150mm (why, oh why, must we mix
units?). Allowing for tyre, that's probably radius 380mm for a ratio of
.4ish. By my reckoning the theoretical maximum angle would be 23-odd
degrees. That sounds quite shallow, but I think people tend to
over-estimate slope angles. On the other hand, I might be wrong. And
yes, I appreciate that there are technique issues not addresses here -
allowing the uni to accelerate, holding the saddle (allowing for an
effective 'over-body-weight' force, riding partially across the slope
and probably others I don't know about.




Note that 26" refers to an approximation of the outside diameter of the
tire, not the size of the rim. So you are overestimating the radius;
it's probably more like 350-360mm on a 26x3" tire.

I am certain that I have ridden down slopes much greater than 23
degrees. For that matter, on roads I have ridden up slopes that steep.
I have ridden down slops where portions of the slope were not visible
from the top of the slope.

The difficulty in calculating a theoretical maximum is that a unicycle
is not a railroad. There are two major effects which increase the
unicyclist's ability to descend steep slopes. One is that a unicycle
naturally "tacks" across the face of a slope, and this effect becomes
greater on steeper slopes. The other is that you don't necessarily
need to apply back pressure to go down a hill; for sufficiently short
sections, you can just spin through them and regain control when you
get to the bottom.


--
tholub
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