measuring mileage: wheels and deals... RE: [at-l] re: Pittsburg(h)

[sloetoe at yahoo.com (Sloetoe)]

--- Walt Daniels <wdlists@optonline.net> wrote:
> Wheeling mileages and GPS mileages measure different things.
> In steep and rocky/twisty terrain, GPS is frequently 10-20%
lower than wheel mileages.

### It gets even better: wheeled mileage can be biased "high" by
simply pushing the wheel faster. This is harder for road runners
to understand than trail hikers, but what NightWheeler wrote of
("GPS measures __________, while wheel measures /\__/\__/\__.")
also works at even a micro level, such that on an ostensibly
flat surface (asphalt measured for a 10k {6.214 mile} road
race), if pushed fast, the wheel will micro-"bounce" over the
road, adding yards to a measured reading -- and thusly
*subtracting* yards from a required length. These "lost" yards
might have taken 1 to 10 seconds to complete, and thus time
keeping and records (and money paid out to record breakers) are
all affected. As a footnote (so to speak), courses are not only
measured slow, but also measured "long" by 50 yards or so, so
that any records established on race day survive course
remeasuring and such. So any of you that have run "certified"
courses have actually run "long" courses *by* *design* -- hope
that helps your running records.....

certifiedtoe

(Oh, and by the way, and in tribute to AT, LT, and now PCT
record setter David Horton, you might google "Horton Miles". As
a race director, David is (in)famous for measuring his
courses...., um...., "forgetfully" long. His "Mountain
Masochist" 50 mile trail race (the 15th or 20th of which was
just run) actually measures something like (SOMETHING like) 54
"statute" miles, although in Horton miles it comes out just
right.      ultratoe)