"Mike S." <mikeshaw2@coxDOTnet> wrote in message news:<edzWb.61049$F15.59449@fed1read06>...
Quoted message said:Quoted message said:Psychology often matters as much as physical dimensions in how things feel to us. Double-blind
testing often shows that we're nowhere near as sensitive as we think.
If the Mavic cranks really do feel "much too wide" compared to the Chorus cranks, but are only 1
mm wider, then it's likely that either you're being influenced by the labels or else aren't
measuring what really affects your feet.
To illustrate how unlikely it is that either of your feet are sensitive to a single millimeter
of width, hold your hand up in front of the computer screen, spread your thumb and fingers, and
try to hold your thumb and forefinger only a millimeter apart. Most people will find it hard to
maintain this tiny distance without noticeable wavering.
(It's easy to cheat--brace your thumb and forefinger against your middle finger.)
For another example, look down and try to hold the side of your shoe a millimeter from the desk.
Or put a thin envelope between the side of your shoe and the desk--that's about a millimeter
wide. Can you feel the difference in width using your foot?
The Mavic may be a millimeter wider than the Chorus, but I suspect that you're probably feeling
something else, even though you write that the bikes are set up the same way. If you're curious,
you might check the seats, pedals, and the curve and thickness of the cranks for more likely
explanations about why one feels "much too wide" when your first measurement shows only a
millimeter difference.
Carl Fogel
People keep trying to make feelings go away by demonstrating something with a static test. Better
to demonstrate it by movement and THEN try and figure it out.
While I agree that most of what anyone feels is in their minds, I gotta wonder why it is that
people insist that there's nothing there. Yeah, 1mm in a static test ain't much, try rotating your
feet around at 90rpm and tell me that there's still nothing to it. In this case, not only are the
crankarms 1mm wider, but also another 2.5mm longer. I dare say that if the arms were the same
length, the OP probably wouldn't have noticed as much. But that he did tells me that there's
SOMETHING going on.
There's gotta be more to it than "its in your head, stupid," otherwise we wouldn't keep getting
these kinds of questions.
Mike "Puzzled by the feelings"
Dear Mike,
Neither the feelings nor the questions are stupid.
But the effects are more likely either due to other unmeasured dimension or else inside our heads.
Measure the thickness of the socks that you wear while riding with a pair of calipers.
How much would wearing an extra pair of socks add to the width between your feet or the distance
between your feet and your shoes?
My ordinary medium-weight socks are about 2mm thick.
That is, the single layer of extra material under the soles of my feet lengthens my legs 2mm.
Combined, the extra pair of socks narrow the distance between my ankles a whopping 4mm.
Does anyone believe that wearing a pair of extra socks in cold weather requires a crank with shorter
pedal arms or a narrower spindle?
Doctors and magicians routinely use placebo effects and misdirection to put notions in our heads.
And we do it to ourselves all the time.
If a single millimeter in actual crank width really did feel "much too wide," then Peter Chisholm
would be selling cranks in half-millimeter widths.
A single millimeter is simply too small a distance for us to notice while wearing shoes. It's under
1% of the distance between our ankles while we pedal. Keep in mind, that this means that each ankle
would be only half a millimeter farther out. Our socks and shoes flex more than that.
U.S. shoes come in half-sizes that are about 3-5 mm apart in length and widths A-E that vary
about 5 mm:
bigfeetstuff.comebrannock.htmOpen ↗
The original post's claims look like this when tabulated
length Q-factor comments ------ ------- -------- Campy NR 170.0mm 135mm grew up on
these Campy Chorus 170.0mm 145mm wide but tolerable Mavic 172.5mm 146mm much too wide
new cranks 165.0mm 145mm much more comfortable
Frankly, it looks as length was the real problem, not width. The rider may have been on the verge of
feeling uncomfortable with a 170mm crank, become unhappy with a 172.5mm crank, and felt much better
when he shortened his crank to 165mm. Dropping 7.5mm in length might make a noticeable difference--
it's about 4.4%. But widening a spindle 1 millimeter from 145mm is only about 0.7%
If so, the rider wouldn't be the first person to confuse width and length when something felt
uncomfortable. Or to mention puzzling feelings.
That the rider and his wife can swap bikes and seats on their tandem suggests just how insensitive
we are to such minor variations. They may be "almost exactly the same size,"
different hip widths and leg lengths for the same height.
Carl Fogel
