On Sat, 25 Dec 2004 15:32:32 -0800, LioNiNoiL_a t_Y a h 0
0_d 0 t_c 0 m <
[email protected]> wrote:
>Peter Cole wrote:
>
>> [Steve Hogg] counsels you to raise your seat 3mm at a time
>> (yeah, right)
>
>Is 3mm too much, or too little?
Dear L.,
Well . . . 3mm is about 0.12 inches (3/25.4), plus or minus
around 0.02 inches (0.5/25.4).
It's also about the thickness of three credit cards, plus or
minus the thickness of two business cards.
More practically, it's just short of an eighth of an inch,
about twice the thickness of the sole of your sock.
To make such fine adjustments on a typically stubborn seat
post, you'll need some good reference markings. Try drawing
a line of very short dashes up the back with a Sharpie.
Some riders believe that they can feel such small
differences immediately.
Other riders believe that it takes a while, but that they
can still notice the otherwise imperceptible difference by
how their knees (or hips) feel after a long ride.
A few of us are curious whether anyone can reliably tell the
difference if someone else raises or lowers the seat 3mm (or
just fiddles with it and doesn't change it at all).
Is there really such sensitivity (either immediately or
after a long ride), or is it just an example of the kind of
expectation-result that blind testing eliminates? When we
know which way we're changing things, we tend to expect
results, and this expectation is often shown by blind
testing to overwhelm our actual judgement.
Complicating the question is the tipping-point. If you keep
raising (or lowering) the seat in steps too small to be
noticed over a comfortable range, you'll still reach a point
where the very next Xmm increase becomes noticeable after a
long ride.
Another step (or two or three), and you'll reach the point
where the rider notices the difference right away.
In both cases, the rider would understandably think that the
increase of Xmm indicated his sensitivity, when in fact his
range of comfort and sensitivity might have actually been
X+X+X+X+X+Xmm.
Given that the usual aim is to raise the seat until an
observer notices that the rider's hips are beginning to
wobble, 3mm is an impressively fine distinction. After all,
the tipping of the hips for an extra 1/8th inch of leg
travel would be quite small--and the rider would probably
compensate unconsciously by bending his ankle to move the
ball of his foot an extra eighth of an inch downward.
Still, you'll probably be happy if you move your seat up (or
down) in tiny increments until it feels good enough (or you
get bored, declare victory, tighten the seat-post, and go
riding). Even if the seat height failed to match some
Platonic ideal, the human body is generally capable of
adapting to ranges of the kind often discussed here.
Here's an example that I've mentioned before of what can be
done by athletes unfamiliar with the importance of fussing
over equipment:
.. . . the unbelievable Mexican runners who
deflated the egos of Colorado's high-altitude mountain-pass
racers some years ago. They came from the Sierra Madre,
lied about their ages because they were afraid of being
refused entry, started off on sandals made from old tires
to meet race requirements, and even took them off to run
bare-foot with enormous leads in the Leadville 100-mile
race:
http://www.cozine.com/archive/cc1994/00060296.htm
[the link seems to be dead now, so here's part of the
article]
" . . . last year's first-place finisher, 55-year-old
Victoriano Churro, a Tarahumara Indian from northwestern
Mexico. Fearing he'd be considered too old to participate,
Churro initially lied about his age, claiming to be 38.
The amazing thing is, he looked so good, no one even
questioned him. He completed the race in just over 20
hours."
"The modest, sedate Tarahumaras, two of whom finished second
and fifth, made a memorable impression with their loin
cloths, tunic-style shirts, peaked caps, and sandals pieced
together from discarded tires scavenged from the Leadville
landfill. The sandals qualified as distance footwear because
the tires still had some tread."
"The Tarahumaras' appearance at the Twin Lakes aid station
prompted one volunteer to tell her young son, 'Don't ever
ask me for $150 running shoes again.'"
I like to imagine these guys coming up behind Lance on
WalMart bikes with rusty chains.
Carl Fogel
