From: bushnell@iscnvx.lmsc.lockheed.com (William D. Bushnell)
Subject: Re: Table of Grades of Selected Roads in the Santa Cruz Mtns.
Organization: Lockheed Missiles and Space Co.
Distribution: ba
Date: Tue, 1 Sep 92 18:04:50 GMT

Since I posted the inflamatory table in question, I suppose it's up to me to
defend it.

In article <la50huINN7lp@exodus.Eng.Sun.COM> bhilden@bigriver.Eng.Sun.COM (Bruce Hildenbrand) writes:
>
>Here we go again!  I took exception to this posting when it originally
>showed up on the net 2 years ago, I do so again, now!
>
>What the post fails to mention is that the numbers reported here
>represent the grade for a short SECTION of road and not the AVERAGE
>grade.

I guess I'm blinded by my own familiarity with the roads included in the
list.  It seems perfectly clear to me what is being measured.  What
I find interesting isn't the average grade but the local gradient of the
steep parts of a road.  Anyone with an Avocet 50 or a topo map and odometer
can figure out the average grade of a climb, but measuring the local gradient
isn't so trivial.

>Because of this, I find this table very misleading and I think,
>if interpreted incorrectly(which will most likely happen, because no
>real clear explanation was given for the length over which the measurements
>apply) it will lead to people getting a false impression as to the
>average gradient of the ascents in the Bay Area.

It seems clear to me that the length of road over which the gradient was
measured is approximately 100 inches, or more precisely

     100*sqrt(g^2 + 1) inches,

where g is the measured gradient.

I agree, though, that some of the numbers in the list are not representative of
the climb as a whole, and even "whole climb" is open to interpretation.  For
example, how does one measure the "whole climb" up Page Mill Rd?  From I-280
to Skyline?  From Alexis Drive to Shotgun Bend or Montebello parking area?

>It seems that Ray Hosler measured the steepest sections of a number of the
>Bay Area's popular climbs which does not give a good indication of the
>average gradient.

...nor does this seem to be the purpose of the list.

>I am sure that Ray had the best of intentions, he just
>should have labeled his measured sections as such.

...and he did.  The measured sections are labeled quite specifically.  I see
nothing misleading here.

>I feel that unless a climb is more of a stair-stepped affair(Page Mill
>is the classic Bay Area example) then the average gradient is more
>appropriate.  Climbs like King's Mountain and Old LaHonda(East side)
>are more like a 7-8% average grade, the steep sections reported
>in Ray Hosler's table are short enough to almost be non-existent
>(sure you may have to get out of the saddle, but you certainly
>are not going to die on them).

I agree that the average grades of Old La Honda Rd and Kings Mountain Rd.
aren't anywhere near the 10% to 16% given in the sample measurements.  But,
again, the local gradient information is what is interesting here, not the
average grade.  Maybe it's fair to scold Ray for measuring only the steep
parts of Old La Honda and for not measuring a more gradual section to get a
balanced view of the road.

The only possibly misleading statement is where Jobst Brandt says of Ray Hosler
in his introduction, "He is careful to get a representative section of road..."
This could be misleading if you interpret "representative section of road" as
representative of the whole climb.

The figures for some of the other roads are more representative of entire
climbs and are entirely believable.  For example, the gradients listed for Sand
Hill Rd., Skyline Blvd., Hwy 84 (west), Haskins Hill (east), Tunitas Creek Rd.,
Joaquin Rd., and Bohlman Rd. are representative of at least moderately long
sections of these roads.

>Anyway, it is interesting that about 1 month after we have a discussion
>about how representing climbs in writing can be misleading, the other side
>of that discussion finally offers data that seems to support their original
>claim!

I don't want to bring personalities and "sides" of a past discussion into this
discussion.  I am interested in the local gradients of the roads in question,
and I think other local readers are too, even if a probable minority of them
have seen this list before.

-- 
bushnell@lmsc.lockheed.com	(Bill Bushnell)
From: khe@hpfcso.FC.HP.COM (Keith Erskine)
Date: Tue, 25 Aug 1992 00:10:47 GMT
Subject: Re: Trispokes
Organization: Hewlett-Packard, Fort Collins, CO, USA