Archive-URL: http://search.bikelist.org/getmsg.asp?Filename=internet-bob.10912.0621.eml
Date: Sat, 5 Dec 2009 07:50:45 -0800
From: eddie flayer <eddie.flayer(AT)att.net>
Subject: [BOB] to Bartoe re: what is planing?

Hello Tim,

This is best I found.  It is an attempt to describe the 
indescribable.  Think it was invented by Matthew Grimm and then in 
dialogue with Jan Heine has become the lore of the bike world.  But 
maybe it exists.  And my experience with my Fuji would suggest it does.

And, for the first time on my Fuji Touring I want to say it is 
happening.  Such a cheap and relatively heavy bike and it just 
"feels" better than just about anything I've owned before.  And I 
have owned many.  Serotta, two Rambouillets two different times, two 
Bleriots two different times, and currently even a custom Steve 
Rex.  And none "seems" to ride quite like and quite as well as the 
Fuji.  I get on the heavy cheap sucker and we fly.  I don't do drugs 
or drink...while riding.


1. Frame stiffness

Frame stiffness has been considered of great importance for more than
50 years, so it's not a recent invention. However, many racers and
riders have preferred lightweight frames, even for flat stages, and
even during times when they cared little about the weight of their
bikes otherwise.

As the "Frame Flex - Does it Matter" article in Bicycle Quarterly
pointed out, racers and builders solved this conundrum by claiming
that high-end steels were stiffer than low-end ones. So a frame made
from Columbus SL (wall thicknesses 0.8-0.6-0.8 mm) was purported to
be stiffer than one made from straight-gauge 1.0 mm tubing. The new
"Supersteels," like Reynolds 753, were said to be stiffer yet - so
racers could ride, and like, 0.7-0.4-0.7 mm frames.

We all know that the explanation was wrong - all steels used on
bicycles have roughly the same modulus of elasticity, so for a given
diameter, the thickest walls (drainpipe in the above examples) were
the stiffest. However, this does not invalidate the observation that
many riders prefer the lightweight, and as we know, flexible frames.

The problem with Schubert et al., and also many of the builders from
the 1980s until today, was that they took the "Stiffness is better"
mantra without looking at what actual riders preferred. Nobody raced
on drainpipe, despite its incredible stiffness...

2. Planing

Planing, as I experience it, is more than just an illusion, but it
may be hard to quantify. Anybody who has raced knows that it is hard
to unlock the reserves of power every human has. It is easy to go at
80% of your max power, hard to go at 90% and almost impossible to go
at 100%.

If you crash on a hill because somebody cuts you off and runs you off
the road, you will be amazed how much faster than the pack you can go
to catch back up. Your max. heart rate is higher than what you
thought it was, etc.

A bike that helps you unlock part of this reserve, a bike that allows
or even entices you to work harder not only will be more fun to ride,
but also faster. If you can ride at 85% of max. your power output
instead of 80% during a century, then you'll be quite a bit faster.
You will be more tired at the end, too.

How do you measure this? A power meter would not measure it. A heart
rate monitor won't, either. If planing does work the way I think, and
if you did a large number of double-blind tests, both power meter and
heart rate meter would show higher numbers, and higher speeds for the
bikes that plane, on average, over the same courses (on days with no
wind, of course). Having two riders, during each ride, following each
other at 1 mile distance (out of sight), one on a planing bike, one
on a non-planing bike, would allow to eliminate the environmental
conditions to some degree.

Another test might just be a double-blind test with different bikes,
some more flexible than others, but otherwise the same. If BQ's
testers can distinguish which bikes are more flexible, then we know
at least that stiffness has an impact. However, this would not prove
whether "planing" brought any performance benefits.

All this would be a lot of effort to try and prove something that
most experienced riders know exists. And just by proving that
"planing" exists, we still wouldn't know how to build planing bikes
for everybody, with different body weights, cadences, etc. In the old
days, the solution was simple: riders were told to adapt their style
to the bikes. That is why all racers used to pedal at roughly 110 rpm
(and still do to a large degree)...

By the way, similar, difficult to quantify qualities are found in
many other areas as well. If you take cars, those that allow the
highest G forces on the skid pad aren't necessarily the fastest,
best-handling on a winding mountain road. More important is how
accessible the handling is, how abrupt the break-away, how precise
the steering, all factors that are hard to measure. The skid pad
tests tell you very little among relatively similar cars... and cars
designed to excell on a skidpad usually will make very poor rallye
cars.
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