Archive-name: bicycles-faq/part5

[Note:  The complete FAQ is available via anonymous ftp from
draco.acs.uci.edu (128.200.34.12), in pub/rec.bicycles.]

------------------------------

Subject: 9.16  Trackstands
From: Rick Smith <ricks@sdd.hp.com>

                How to trackstand on a road bike.
 
 With acknowledgments to my trackstanding mentor,
               Neil Bankston.

  Practice, Practice, Practice, Practice, ....

  1. Wear tennis shoes.
  2. Find an open area, like a parking lot that has a slight grade to it.
  3. Put bike in a gear around a 42-18.
  4. Ride around out of the saddle in a counter-clockwise circle, about
     10 feet in diameter.

     Label Notation for imaginary points on the circle:
       'A' is the lowest elevation point on the circle.
       'B' is the 90 degrees counterclockwise from 'A' .
       'C' is the highest elevation point on the circle.
       'D' is the 90 degrees counterclockwise from 'C' .

        C
      /   \
     D     B       Aerial View
      \   /
        A

   5. Start slowing down, feeling the different sensation as the bike
      transitions between going uphill (B) and downhill (D).
   6. Start trying to go real slowly through the A - B region of the circle.
      This is the region you will use for trackstanding.  Ride the rest of
      the circle as you were in step 5.
 
      The trackstanding position (aerial view again):

        ---|   /
 ------| |----/
           |---     /
 

      The pedal are in a 3 o'clock - 9 o'clock arrangement (in other
      words, parallel to the ground).  Your left foot is forward, your
      wheel is pointed left.  You are standing and shifting you weight
      to keep balance.  The key to it all is this:

   If you start to fall left, push on the left peddle to move the
   bike forward a little and bring you back into balance.

   If you start to fall right, let up on the peddle and let the
   bike roll back a little and bring you back into balance.

    7. Each time you roll through the A - B region, try to stop when
       the left peddle is horizontal and forward.  If you start to
       lose your balance, just continue around the circle and try it
       again.

    8. Play with it.  Try doing it in various regions in the circle,
       with various foot position, and various amounts of turn in your
       steering.  Try it on different amounts of slope in the
       pavement.  Try different gears.  What you are shooting for is
       the feel that's involved, and it comes with practice.

The why's of trackstanding:

  Why is road bike specified in the title?
      A true trackstand on a track bike is done differently.  A track
      bike can be peddled backwards, and doesn't need a hill to
      accomplish the rollback affect.  Track racing trackstands
      are done opposite of what is described.  They take place on the
      C - D region of the circle, with gravity used for the roll
      forward, and back pedaling used for the rollback.  This is so
      that a racer gets the assist from gravity to get going again
      when the competition makes a move.

  Why a gear around 42-18?
      This is a reasonable middle between too small, where you would
      reach the bottom of the stroke on the roll forward, and too big,
      where you couldn't generate the roll forward force needed.

  Why is the circle counter-clockwise?
      Because I assume you are living in an area where travel is done
      on the right side of the road.  When doing trackstands on the road,
      most likely it will be at traffic lights.  Roads are crowned - higher
      in the middle, lower on the shoulders - and you use this crown as
      the uphill portion of the circle (region A-B).  If you are in a
      country where travel is done on the left side of the road,
      please interpret the above aerial views as subterranial.

  Why is this done out of the saddle?
      It's easier!!  It can be done in while seated, but you lose the
      freedom to do weight adjustments with your hips.

  Why is the left crank forward?
      If your right crank was forward, you might bump the front wheel
      with your toe.  Remember the steering is turned so that the back
      of the front wheel is on the right side of the bike.  Some bikes
      have overlap of the region where the wheel can go and your foot
      is.  Even if your current bike doesn't have overlap, it's better
      to learn the technique as described in case you are demonstrating
      your new skill on a bike that does have overlap.

  Why the A - B region?
      It's the easiest.  If you wait till the bike is around 'B', then
      you have to keep more force on the peddle to hold it still.  If
      you are around the 'A' point, there may not be enough slope to
      allow the bike to roll back.

Questions:

  What do I  do if I want to stop on a downhill?
      While there are techniques that can be employed to keep you in
      the pedals, for safety sake I would suggest getting out of the
      pedals and putting your foot down.

Other exercises that help:

    Getting good balance.  Work through this progression:
      1. Stand on your right foot.  Hold this until it feels stable.
      2. Close your eyes.  Hold this until it feels stable.
      3. Go up on your toes.  Hold this until it feels stable.
      4. If you get to here, never mind, your balance is already wonderful,
         else repeat with other foot.

------------------------------

Subject: 9.17  Front Brake Usage
From: John Forester <jforester@cup.portal.com>

   I have dealt for many years with the problem of explaining front
brake use, both to students and to courtrooms, and I have reached
some conclusions, both about the facts and about the superstitions.

   The question was also asked about British law and front brakes.
I'll answer that first because it is easier. British law requires
brakes on both wheels, but it accepts that a fixed gear provides the
required braking action on the rear wheel. I think that the
requirement was based on reliability, not on deceleration. That is,
if the front brake fails, the fixed-gear cyclist can still come to a
stop.

   In my house (in California) we have three track-racing bikes
converted to road use by adding brakes. Two have only front brakes
while the third has two brakes. We have had no trouble at all, and we
ride them over mild hills. The front-brake-only system won't meet the
normal U.S. state traffic law requirement of being able to skid one
wheel, because that was written for coaster-braked bikes, but it
actually provides twice the deceleration of a rear-wheel-braked bike
and nobody, so far as I know, has ever been prosecuted for using such
a setup.

   The superstitions about front brake use are numerous. The most
prevalent appears to be that using the front brake without using the
rear brake, or failing to start using the rear brake before using the
front brake, will flip the cyclist. The other side of that
superstition is that using the rear brake will prevent flipping the
bicycle, regardless of how hard the front brake is applied.

   The truth is that regardless of how hard the rear brake is
applied, or whether it is applied at all, the sole determinant (aside
from matters such as bicycle geometry, weight and weight distribution
of cyclist and load, that can't practically be changed while moving)
of whether the bicycle will be flipped is the strength of application
of the front brake. As the deceleration to produce flip is
approached, the weight on the rear wheel decreases to zero, so that
the rear wheel cannot produce any deceleration; with no application
of the rear brake it rolls freely, with any application at all it
skids at a force approaching zero. With typical bicycle geometry, a
brake application to attempt to produce a deceleration greater than
0.67 g will flip the bicycle. (Those who advocate the cyclist moving
his butt off and behind the saddle to change the weight distribution
achieve a very small increase in this.)

   A typical story is that of a doctor who, now living in the higher-
priced hilly suburbs, purchased a new bicycle after having cycled to
med school on the flats for years. His first ride was from the bike
shop over some minor hills and then up the 15% grade to his house.
His second ride was down that 15% grade. Unfortunately, the rear
brake was adjusted so that it produced, with the lever to the
handlebar, a 0.15 g deceleration. The braking system would meet the
federal requirements of 0.5 g deceleration with less than 40 pounds
grip on the levers, because the front brake has to do the majority of
the work and at 0.5 g there is insufficient weight on the rear wheel
to allow much more rear brake force than would produce 0.1 g
deceleration. (The U.S. regulation allows bicycles with no gear
higher than 60 inches to have only a rear-wheel brake that provides
only 0.27 g deceleration.) I don't say that the rear brake adjustment
of the bicycle in the accident was correct, because if the front
brake fails then the rear brake alone should be able to skid the rear
wheel, which occurs at about 0.3 g deceleration. The doctor starts
down the hill, coasting to develop speed and then discovering that he
can't slow down to a stop using the rear brake alone. That is because
the maximum deceleration produced by the rear brake equalled, almost
exactly, the slope of the hill. He rolls down at constant speed with
the rear brake lever to the handlebar and the front brake not in use
at all. He is afraid to apply the front brake because he fears that
this will flip him, but he is coming closer and closer to a curve,
after which is a stop sign. At the curve he panics and applies the
front brake hard, generating a force greater than 0.67 g deceleration
and therefore flipping himself. Had he applied the front brake with
only a force to produce 0.1 g deceleration, even 100 feet before the
curve, he would have been safe, but in his panic he caused precisely
the type of accident that he feared. He thought that he had a good
case, sued everybody, and lost. This is the type of superstition that
interferes with the cycling of many people.

   My standard instruction for people who fear using the front brake
is the same instruction for teaching any person to brake properly.
Tell them to apply both brakes simultaneously, but with the front
brake 3 times harder than the rear brake. Start by accelerating to
road speed and stopping with a gentle application. Then do it again
with a harder application, but keeping the same 3 to 1 ratio. Then
again, harder still, until they feel the rear wheel start to skid.
When the rear wheel skids with 1/4 of the total braking force applied
to it, that shows that the weight distribution has now progressed as
far to the front wheel as the average cyclist should go. By repeated
practice they learn how hard this is, and attain confidence in their
ability to stop as rapidly as is reasonable without any significant
risk.

------------------------------

Subject: 9.18  Slope Wind, the Invisible Enemy
From: Jobst Brandt <jbrandt@hpl.hp.com>

Wind as well as relative wind caused by moving through still air
demands most of a bicyclists effort on level ground.  Most riders
recognize when they are subjected to wind because it comes in gusts
and these gusts can be distinguished from the more uniform wind caused
by moving through still air.  That's the catch.  At the break of dawn
there is often no wind as such but cool air near the ground, being
colder and more dense than higher air slides downslope as a laminar
layer that has no turbulent gusts.

Wind in mountain valleys generally blows uphill during the heat of the
day and therefore pilots of light aircraft are warned to take off
uphill against the morning slope wind.  Slope wind, although detectable,
is not readily noticed when standing or walking because it has
negligible effect and does not come in apparent gusts.  The bicyclist,
in contrast, is hindered by it but cannot detect it because there is
always wind while riding.

Slope wind, as such, can be up to 10 mph before it starts to take on
the characteristics that we expect of wind.  It is doubly deceptive
when it comes from behind because it gives an inflated speed that can
be mistakenly attributed to great fitness that suddenly vanishes when
changing course.  If you live near aspen or poplars that tend to fan
their leaves in any breeze, you will not be fooled.

------------------------------

Subject: 9.19  Reflective Tape
From: Jobst Brandt <jbrandt@hpl.hp.com>

Reflective tape is available in most better bike shops in various
forms, most of which is pre-cut to some preferred shape and designed
for application to some specific part of the bike or apparel.  The most
effective use of such tape is on moving parts such as pedals, heel of
the shoe or on a place that is generally overlooked, the inside of the
rim.

First, it is appropriate to note that car headlights generally produce
white light and a white or, in fact, colorless reflector returns more
of this light to its source than ones with color filters or selective
reflection.  Red, for instance, is not nearly as effective as white.

Placing reflective tape on the inside of the rims between the spokes
is a highly effective location for night riding because it is visible
equally to the front and rear while attracting attention through its
motion.  It is most effective when applied to less than half the rim
in a solid block.  Five inter-spoke sections does a good job.  One can
argue that it isn't visible from the side (if the rim is not an aero
cross section) but the major hazard is from the front and rear.

Be seen on a bike!  It's good for your health.

------------------------------

Subject: 9.20  Nutrition
From: Bruce Hildenbrand <bhilden@unix386.Convergent.COM>

Oh well, I have been promising to do this for a while and given the present
discussions on nutrition, it is about the right time.  This article was
written in 1980 for Bicycling Magazine.  It has been reprinted in over 30
publications, been the basis for a chapter in a book and cited numerous
other times.  I guess somebody besides me thinks its OK.  If you disagree
with any points, that's fine, I just don't want to see people take exception
based on their own personal experiences because everyone is different and
psychological factors play a big role(much bigger than you would think)
on how one perceives his/her own nutritional requirements.  Remember that
good nutrition is a LONG TERM process that is not really affected by short
term events(drinking poison would be an exception).  If it works for you
then do it!!!  Don't preach!!!!
 
 

  BASIC NUTRITION PRIMER

Nutrition in athletics is a very controversial topic.  However, for
an athlete to have confidence that his/her diet is beneficial he/she
must understand the role each food component plays in the body's
overall makeup.  Conversely, it is important to identify and understand
the nutritional demands on the physiological processes of the body
that occur as a result of racing and training so that these needs
can be satisfied in the athlete's diet.
 
For the above reasons, a basic nutrition primer should help the athlete
determine the right ingredients of his/her diet which fit training and
racing schedules and existing eating habits.  The body requires three
basic components from foods: 1) water; 2) energy; and 3)nutrients.
 
WATER
 
Water is essential for life and without a doubt the most important
component in our diet.  Proper hydrations not only allows the body to
maintain structural and biochemical integrity, but it also prevents
overheating, through sensible heat loss(perspiration).  Many cyclists have
experienced the affects of acute fluid deficiency on a hot day, better
known as heat exhaustion.  Dehydration can be a long term problem,
especially at altitude, but this does not seem to be a widespread
problem among cyclists and is only mentioned here as a reminder(but
an important one).
 
ENERGY
 
Energy is required for metabolic processes, growth and to support
physical activity.  The Food and Nutrition Board of the National
Academy of Sciences has procrastinated in establishing a Recommended
Daily Allowance(RDA) for energy the reasoning being that such a daily
requirement could lead to overeating.  A moderately active 70kg(155lb)
man burns about 2700 kcal/day and a moderately active 58kg(128lb) woman
burns about 2500 kcal/day.
 
It is estimated that cyclists burn 8-10 kcal/min or about 500-600
kcal/hr while riding(this is obviously dependent on the level of
exertion).  Thus a three hour training ride can add up to 1800
kcals(the public knows these as calories) to the daily energy demand
of the cyclist.  Nutritional studies indicate that there is no
significant increase in the vitamin requirement of the athlete as a
result of this energy expenditure.
 
In order to meet this extra demand, the cyclist must increase his/her
intake of food.  This may come before, during or after a ride but most
likely it will be a combination of all of the above.  If for some
reason extra nutrients are required because of this extra energy
demand, they will most likely be replenished through the increased
food intake.  Carbohydrates and fats are the body's energy sources and
will be discussed shortly.
 
NUTRIENTS
 
This is a broad term and refers to vitamins, minerals, proteins, carbohydrates,
fats, fiber and a host of other substances.  The body is a very complex product
of evolution.  It can manufacture many of the resources it needs to survive.
However, vitamins, minerals and essential amino acids(the building blocks of
proteins) and fatty acids cannot be manufactured, hence they must be supplied
in our food to support proper health.
 
Vitamins and Minerals
 
No explanation needed here except that there are established RDA's for most
vitamins and minerals and that a well balanced diet, especially when
supplemented by a daily multivitamin and mineral tablet should meet all
the requirements of the cyclist.
 
Proper electrolyte replacement(sodium and potassium salts) should be
emphasized, especially during and after long, hot rides.  Commercially
available preparations such as Exceed, Body Fuel and Isostar help
replenish electrolytes lost while riding.
 
Proteins
 
Food proteins are necessary for the synthesis of the body's skeletal(muscle,
skin, etc.) and biochemical(enzymes, hormones, etc.)proteins.  Contrary
to popular belief, proteins are not a good source of energy in fact they
produce many toxic substances when they are converted to the simple sugars
needed for the body's energy demand.
 
Americans traditionally eat enough proteins to satisfy their body's
requirement.  All indications are that increased levels of exercise do
not cause a significant increase in the body's daily protein
requirement which has been estimated to be 0.8gm protein/kg body
weight.
 
Carbohydrates
 
Carbohydrates are divided into two groups, simple and complex, and serve
as one of the body's two main sources of energy.
 
Simple carbohydrates are better known as sugars, examples being fructose,
glucose(also called dextrose), sucrose(table sugar) and lactose(milk sugar).
 
The complex carbohydrates include starches and pectins which are multi-linked
chains of glucose.  Breads and pastas are rich sources of complex
carbohydrates.
 
The brain requires glucose for proper functioning which necessitates a
carbohydrate source.  The simple sugars are quite easily broken down to
help satisfy energy and brain demands and for this reason they are an ideal
food during racing and training.  The complex sugars require a substantially
longer time for breakdown into their glucose sub units and are more suited
before and after riding to help meet the body's energy requirements.
 
Fats
 
Fats represent the body's other major energy source.  Fats are twice as
dense in calories as carbohydrates(9 kcal/gm vs 4 kcal/gm) but they are
more slowly retrieved from their storage units(triglycerides) than
carbohydrates(glycogen).  Recent studies indicate that caffeine may help
speed up the retrieval of fats which would be of benefit on long rides.
 
Fats are either saturated or unsaturated and most nutritional experts
agree that unsaturated, plant-based varieties are healthier.  Animal
fats are saturated(and may contain cholesterol), while plant based fats
such as corn and soybean oils are unsaturated.  Unsaturated fats are
necessary to supply essential fatty acids and should be included in the
diet to represent about 25% of the total caloric intake.  Most of this
amount we don't really realize we ingest, so it is not necessary to heap
on the margarine as a balanced diet provides adequate amounts.
 
WHAT THE BODY NEEDS
 
Now that we have somewhat of an understanding of the role each food
component plays in the body's processes let's relate the nutritional
demands that occur during cycling in an attempt to develop
an adequate diet.  Basically our bodies need to function in three
separate areas which require somewhat different nutritional considerations.
These areas are: 1) building; 2) recovery; and 3) performance.
 
Building
 
Building refers to increasing the body's ability to perform physiological
processes, one example being the gearing up of enzyme systems necessary
for protein synthesis, which results in an increase in muscle mass, oxygen
transport, etc.  These systems require amino acids, the building blocks of
proteins.  Hence, it is important to eat a diet that contains quality proteins
(expressed as a balance of the essential amino acid sub units present)fish,
red meat, milk and eggs being excellent sources.
 
As always, the RDA's for vitamins and minerals must also be met but, as with
the protein requirement, they are satisfied in a well balanced diet.
 
Recovery
 
This phase may overlap the building process and the nutritional requirements
are complimentary.  Training and racing depletes the body of its energy
reserves as well as loss of electrolytes through sweat.  Replacing the
energy reserves is accomplished through an increased intake of complex
carbohydrates(60-70% of total calories) and to a lesser extent fat(25%).
Replenishing lost electrolytes is easily accomplished through the use
of the commercial preparations already mentioned.
 
Performance
 
Because the performance phase(which includes both training rides and
racing)spans at most 5-7 hours whereas the building and recovery phases
are ongoing processes, its requirements are totally different from the
other two.  Good nutrition is a long term proposition meaning the effects
of a vitamin or mineral deficiency take weeks to manifest themselves.
This is evidenced by the fact that it took many months for scurvy to
show in sailors on a vitamin C deficient diet.  What this means is that
during the performance phase, the primary concern is energy replacement
(fighting off the dreaded "bonk") while the vitamin and mineral demands
can be overlooked.
 
Simple sugars such a sucrose, glucose and fructose are the quickest
sources of energy and in moderate quantities of about 100gm/hr(too much
can delay fluid absorption in the stomach) are helpful in providing fuel
for the body and the brain.  Proteins and fats are not recommended because
of their slow and energy intensive digestion mechanism.
 
Short, one day rides or races of up to one hour in length usually require
no special nutritional considerations provided the body's short term energy
stores (glycogen) are not depleted which may be the case during multi-day
events.
 
Because psychological as well as physiological factors determine performance
most cyclists tend to eat and drink whatever makes them feel "good" during a
ride.  This is all right as long as energy considerations are being met and
the stomach is not overloaded trying to digest any fatty or protein containing
foods.  If the vitamin and mineral requirements are being satisfied during the
building and recovery phases no additional intake during the performance phase
is necessary.
 
 
IMPLICATIONS
 
Basically, what all this means is that good nutrition for the cyclist is
not hard to come by once we understand our body's nutrient and energy
requirements.  If a balanced diet meets the RDA's for protein, vitamins
and minerals as well as carbohydrate and fat intake for energy then everything
should be OK nutritionally.  It should be remembered that the problems
associated with nutrient deficiencies take a long time to occur.  Because
of this it is not necessary to eat "right" at every meal which explains
why weekend racing junkets can be quite successful on a diet of tortilla
chips and soft drinks.  However, bear in mind that over time, the body's
nutritional demands must be satisfied.  To play it safe many cyclists
take a daily multivitamin and mineral supplement tablet which has no adverse
affects and something I personally recommend.  Mega vitamin doses(levels
five times or more of the RDA) have not been proven to be beneficial and may
cause some toxicity problems.
 
GREY NUTRITION
 
"Good" nutrition is not black and white.  As we have seen, the body's
requirements are different depending on the phase it is in.  While the
building and recovery phases occur somewhat simultaneously the performance
phase stands by itself.  For this reason, some foods are beneficial during
one phase but not during another.  A good example is the much maligned
twinkie.  In the performance phase it is a very quick source of energy
and quite helpful.  However, during the building phase it is not necessary
and could be converted to unwanted fat stores.  To complicate matters, the
twinkie may help replenish energy stores during the recovery phase however,
complex carbohydrates are probably more beneficial.  So, "one man's meat
may be another man's poison."
 
NUTRIENT DENSITY
 
This term refers to the quantity of nutrients in a food for its accompanying
caloric(energy) value.  A twinkie contains much energy but few vitamins and
minerals so has a low nutrient density.  Liver, on the other hand, has a
moderate amount of calories but is rich in vitamins and minerals and is
considered a high nutrient density food.
 
Basically, one must meet his/her nutrient requirements within the
constraints of his/her energy demands.  Persons with a low daily
activity level have a low energy demand and in order to maintain their
body weight must eat high nutrient density foods.  As already
mentioned, a cyclist has an increased energy demand but no significant
increase in nutrient requirements.  Because of this he/she can eat
foods with a lower nutrient density than the average person.  This
means that a cyclist can be less choosy about the foods that are eaten
provided he/she realizes his/her specific nutrient and energy
requirements that must be met.
 
BALANCED DIET
 
Now, the definition of that nebulous phrase, "a balanced diet".  Taking into
consideration all of the above, a diet emphasizing fruits and vegetables
(fresh if possible), whole grain breads, pasta,  cereals, milk, eggs, fish and
red meat(if so desired) will satisfy long term nutritional demands.
These foods need to be combined in such a way that during the building and
recovery phase, about 60-70% of the total calories are coming from carbohydrate
sources, 25% from fats and the remainder(about 15%) from proteins.
 
It is not necessary to get 100% of the RDA for all vitamins and minerals
at every meal.  It may be helpful to determine which nutritional
requirements you wish to satisfy at each meal.  Personally, I use breakfast
to satisfy part of my energy requirement by eating toast and cereal.  During
lunch I meet some of the energy, protein and to a lesser extent vitamin and
mineral requirements with such foods as yogurt, fruit, and peanut butter
and jelly sandwiches.  Dinner is a big meal satisfying energy, protein,
vitamin and mineral requirements with salads, vegetables, pasta, meat and
milk.  Between meal snacking is useful to help meet the body's energy
requirement.
 
CONCLUSION
 
All this jiberish may not seem to be telling you anything you couldn't
figure out for yourself.  The point is that "good" nutrition is not
hard to achieve once one understands the reasons behind his/her dietary
habits.  Such habits can easily be modified to accommodate the nutritional
demands of cycling without placing any strict demands on one's lifestyle.

------------------------------

Subject: 9.21  Nuclear Free Energy Bar Recipe
From: Phil Etheridge <phil@massey.ac.nz>

                Nuclear Free Energy Bars
                ~~~~~~~~~~~~~~~~~~~~~~~~
Comments and suggestions welcome.

They seem to work well for me.  I eat bananas as well, in about equal quanities
to the Nuclear Free Energy Bars.  I usually have two drink bottles, one with
water to wash down the food, the other with a carbo drink.

You will maybe note that there are no dairy products in my recipe -- that's
because I'm allergic to them.  You could easily replace the soy milk powder
with the cow equivalent, but then you'd definitely have to include some
maltodextrin (my soy drink already has some in it).  I plan to replace about
half the honey with maltodextrin when I find a local source.  If you prefer
cocoa to carob, you can easily substitute.

C = 250 ml cup, T = 15 ml tablespoon

1 C Oat Bran
1/2 C Toasted Sunflower and/or Sesame seeds, ground (I use a food processor)
1/2 C Soy Milk Powder (the stuff I get has 37% maltodextrin, ~20% dextrose*)
1/2 C Raisins
2T Carob Powder

Mix well, then add to

1/2 C Brown Rice, Cooked and Minced (Using a food processor again)
1/2 C Peanut Butter (more or less, depending on consistency)
1/2 C Honey (I use clear, runny stuff, you may need to warm if it's thicker
 and/or add a little water)

Stir and knead (I knead in more Oat Bran or Rolled Oats) until thoroughly
mixed.  A cake mixer works well for this.  The bars can be reasonably soft, as
a night in the fridge helps to bind it all together.  Roll or press out about
1cm thick and cut.  Makes about 16, the size I like them (approx 1cm x 1.5cm x
6cm).

* Can't remember exact name, dextrose something)

------------------------------

Subject: 9.22  Powerbars Recipe
From: John McClintic <johnm@hammer.TEK.COM>

Have you ever watched a hummingbird? Think about it! Hummingbirds
eat constantly to survive. We lumpish earthbound creatures are in
no position to imitate this. Simply, if we overeat we get fat.

There are exceptions: those who exercise very strenuously can
utilize - indeed, actually need - large amounts of carbohydrates.

For example, Marathon runners "load" carbohydrates by stuffing
themselves with pasta before a race. On the flip side Long-distance
cyclists maintain their energy level by "power snacking".

With reward to the cyclist and their need for "power snacking"
I submit the following "power bar" recipe which was originated
by a fellow named Bill Paterson. Bill is from Portland Oregon.

The odd ingredient in the bar, paraffin, is widely used in chocolate
manufacture to improve smoothness and flowability, raise the melting
point, and retard deterioration of texture and flavor. Butter can be
used instead, but a butter-chocolate mixture doesn't cover as thinly
or smoothly.

POWER BARS
----------

1  cup regular rolled oats
1/2  cup sesame seed
1 1/2 cups dried apricots, finely chopped
1 1/2 cups raisins
1 cup shredded unsweetened dry coconut
1 cup blanched almonds, chopped
1/2  cup nonfat dry milk
1/2  cup toasted wheat germ
2 teaspoons butter or margarine
1 cup light corn syrup
3/4 cup sugar
1 1/4 cups chunk-style peanut butter
1 teaspoon orange extract
2 teaspoons grated orange peel
1 package (12 oz.) or 2 cups semisweet chocolate
 baking chips
4  ounces paraffin or 3/4 cup (3/4 lb.) butter or
 margarine

Spread oats in a 10- by 15-inch baking pan. Bake in a 300 degree
oven until oats are toasted, about 25 minutes. Stir frequently to
prevent scorching.

Meanwhile, place sesame seed in a 10- to 12-inch frying pan over
medium heat. Shake often or stir until seeds are golden, about 7 minutes.

Pour into a large bowl.  Add apricots, raisins, coconut, almonds,
dry milk, and wheat germ; mix well.  Mix hot oats into dried fruit
mixture.

Butter the hot backing pan; set aside.

In the frying pan, combine corn syrup and sugar; bring to a rolling
boil over medium high heat and quickly stir in the peanut butter,
orange extract, and orange peel.

At once, pour over the oatmeal mixture and mix well. Quickly spread
in buttered pan an press into an even layer. Then cover and chill
until firm, at least 4 hours or until next day.

Cut into bars about 1 1/4 by 2 1/2 inches.

Combine chocolate chips and paraffin in to top of a double boiler.
Place over simmering water until melted; stir often. Turn heat to low.

Using tongs, dip 1 bar at a time into chocolate, hold over pan until
it stops dripping (with paraffin, the coating firms very quickly), then
place on wire racks set above waxed paper.

When firm and cool (bars with butter in the chocolate coating may need
to be chilled), serve bars, or wrap individually in foil. Store in the
refrigerator up to 4 weeks; freeze to store longer. Makes about 4 dozen
bars, about 1 ounce each.

Per piece: 188 cal.; 4.4 g protein; 29 g carbo.; 9.8 g fat;
    0.6 mg chol.; 40 mg sodium.

------------------------------

Subject: 9.23  Calories burned by cycling
From: Jeff Patterson <jpat@hpsad.sad.hp.com>

The following table appears in the '92 Schwinn ATB catalog which references
Bicycling, May 1989:
---------
Speed
(mph)    12   14   15   16   17   18   19
Rider
Weight         Calories/Hr
110     293  348  404  448  509  586  662
120     315  375  437  484  550  634  718
130     338  402  469  521  592  683  773
140     360  430  502  557  633  731  828
150     383  457  534  593  675  779  883
160     405  485  567  629  717  828  938
170     427  512  599  666  758  876  993
180     450  540  632  702  800  925 1048
190     472  567  664  738  841  973 1104
200     495  595  697  774  883 1021 1159

 (flat terrain, no wind, upright position)

------------------------------

Subject: 9.24  Road Rash Cures
From: E Shekita <shekita@provolone.cs.wisc.edu>

[Ed note:  This is a condensation of a summary of cures for road rash that
Gene posted.]

The July 1990 issue of Bicycle Guide has a decent article on road
rash. Several experienced trainers/doctors are quoted.  They generally
recommended:

   - cleaning the wound ASAP using an anti-bacterial soap such as Betadine.
     Showering is recommended, as running water will help flush out dirt
     and grit. If you can't get to a shower right away, at the very least
     dab the wound with an anti-bacteria solution and cover the wound with
     a non-stick telfa pad coated with bactrin or neosporin to prevent
     infection and scabbing. The wound can then be showered clean when you
     get home. It often helps to put an ice bag on the wound after it has
     been covered to reduce swelling.

   - after the wound has been showered clean, cover the wound with either
     1) a non-stick telfa pad coated with bactrin or neosporin, or 2) one
     of the Second Skin type products that are available. If you go the telfa
     pad route, daily dressing changes will be required until a thin layer
     of new skin has grown over the wound. If you go the Second Skin route,
     follow the directions on the package.

The general consensus was that scabbing should be prevented and that the
Second Skin type products were the most convenient -- less dressing changes
and they hold up in a shower. (Silvadene was not mentioned, probably because
it requires a prescription.)

It was pointed out that if one of the above treatments is followed, then
you don't have to go crazy scrubbing out the last piece of grit or dirt
in the wound, as some people believe. This is because most of the grit
will "float" out of the wound on its own when a moist dressing is used.

There are now products that go by the names Bioclusive, Tegaderm,
DuoDerm, Op-Site, Vigilon, Spenco 2nd Skin, and others, that are like
miracle skin. This stuff can be expensive ($5 for 8 3x4 sheets), but
does not need to be changed.  They are made of a 96% water substance
called hydrogel wrapped in thin porous plastic.  Two non-porous plastic
sheets cover the hydrogel; One sheet is removed so that the hydrogel
contacts the wound and the other non-porous sheet protects the wound.

These products are a clear, second skin that goes over the cleaned
(ouch!) wound. They breathe, are quite resistant to showering, and
wounds heal in around 1 week.  If it means anything, the Olympic
Training Center uses this stuff. You never get a scab with this, so you
can be out riding the same day, if you aren't too sore.

It is important when using this treatment, to thoroughly clean the
wound, and put the bandage on right away. It can be obtained at most
pharmacies.  Another possible source is Spenco second skin, which is
sometimes carried by running stores and outdoor/cycling/ stores.  If
this doesn't help, you might try a surgical supply or medical supply
place. They aren't as oriented toward retail, but may carry larger sizes
than is commonly available. Also, you might check with a doctor, or
university athletic department people.

------------------------------

Subject: 9.25  Knee problems
From: Roger Marquis <marquis@well.sf.ca.us>

As the weather becomes more conducive to riding and the
racing season gets going and average weekly training distances
start to climb a few of us will have some trouble with our
knees. Usually knee problem are caused by one of four things:
 
     1)  Riding too hard, too soon. Don't get impatient. It's
going to be a long season and there's plenty of time to get in
the proper progression of efforts. Successful cycling is a matter
of listening to your body. When you see riders burning out,
hurting themselves and just not progressing past a certain point
you can be fairly certain that it is because they are not paying
enough attention to what their body is telling them.
 
     2)  Too many miles. Your body is not a machine. It cannot be
expected to take whatever miles you feel compelled to ride
without time to grow and adapt. If you keep this in mind whenever
you feel like increasing your average weekly mileage by more than
forty miles over two or three weeks you should have no problems.
 
     3)  Low, low rpms (also excess crank length). Save those big
ring climbs and big gear sprints for later in the season. This is
the time of year to develop fast twitch muscle fibers. That means
spin, spin, spin. You don't have to spin all the time but the
effort put into small gear sprints and high rpm climbing now will
pay off later in the season.
 
     4)  Improper position on the bike. Unfortunately most
bicycle salespeople in this country have no idea how to properly
set saddle height. The most common error being to set it too low.
This is very conducive to developing knee problems because of the
excessive bend at the knee when the pedal is at, and just past,
top dead center.

Make sure your seat and cleats are adjusted properly by following the
adjustment procedures found elsewhere.

If after all this you're still having knee problems:
 
     1) Check for leg length differences both below and above the
knee. If the difference is between 2 and 8 millimeters you can
correct it by putting spacers under one cleat. If one leg is
shorter by more than a centimeter or so you might experiment with
a shorter crank arm on the short leg side.
 
     2) Use shorter cranks. For some riders this helps keep pedal
speed up and knee stress down. I'm 6 ft. 1/2 in. and I ride 170mm
cranks for most of the season.
 
     3) Try the Fit-Kit R.A.D. cleat alignment device and/or a
rotating type cleat/pedal like the Time pedal.
 
     4)  Cut way back on mileage and intensity (This is a last
resort for obvious reasons). Sometimes a prolonged rest is the
only way to regain full functionality and is usually required
only if you try to "train through" any pain.
 
------------------------------

Subject: 9.26  Cycling Psychology
From: Roger Marquis <marquis@netcom.com>

     Motivation, the last frontier. With enough of it any
ordinary person can become a world class athlete. Without it this
same person could end up begging for change on Telegraph ave.
Even a tremendously talented rider will go nowhere without
motivation. How do some riders always seem to be so motivated?
What are the sources of their motivation? This has been a central
theme of sports psychology since its beginning when Triplett
studied the effects of audience and competition on performance in
the late nineteenth century. Though a great deal has been written
on motivation since Triplett it is an individual construct. As an
athlete you need to identify what motivates you and cultivate the
sources of your motivation.

     * One of the best sources of motivation is setting goals. Be
specific, put it down on paper. Define your goals clearly and
make them attainable. Short term goals are more important than
long term goals and should be even more precisely defined Set
long term goals such as training at least five days a week,
placing in specific races, upgrading, etc.. Set short term goals
for things like going on a good ride this afternoon, doing five
sprints, bettering your time up Wildcat, etc.. DO NOT STRESS
WINNING when defining your goals. Instead stress enjoying the
ride and doing your best in every ride and race.

     * Do it together. Going to races with friends, training
together and racing as a team is great for motivation. This is
what clubs should be all about.

     * Do it frequently. Regularity makes difficult tasks easy.
If you make it a point to ride every day, or at least five times
a week (to be competitive), making the daily ride will become
automatic.

     * Cycling books and videos are tremendously motivating as
are new bike parts, new clothing, new roads, nice weather, losing
weight, seeing friends, getting out of the city and breathing
fresh air, riding hard and feeling good and especially that great
feeling of accomplishment and relaxation at the end of every ride
that makes life beautiful.

                         ==============

     While high levels of arousal (motivational energy) are
generally better for shorter rides and track races, be careful
not to get over-aroused before longer, harder races. Stay relaxed
and conserve precious energy for that crosswind section or sprint
where you'll need all the strength you've got. Learn how psyched
you need to be to do your best and be aware of when you are over
or under aroused.

     It's not uncommon, especially for novices, to be so nervous
before the start that they are already fatigued on the line. This
much stress is dangerous and should be recognized and controlled
immediately. If you get too stressed before a race try counting
to ten, breathing deeply, stretching, talking to friends, finding
a quiet place to warm-up, or a crowded place to warm-up,
depending on your inclination, and remember that the stress will
disappearas soon as the race starts. Racing takes too much
concentration to spare any for worrying.

     Every athlete needs to be adept in stress management. One
new technique used to reduce competitive anxiety is imagery.
Mental practice has been credited with almost miraculous
improvements in fine motor skills (archery, tennis) but its
greatest value in gross motor sports is in stress reduction.
Actually winning a race can also help put an end to excessive
competitive anxiety. But if you have never won nervousness may be
keeping you from winning. If you find yourself getting
overstressed whenever you think about winning, or even riding, a
race try this; Find a quiet, relaxing place to sit and think
about racing. Second; Picture yourself driving to the race in a
very relaxed and poised state of mind. Continue visualizing the
day progressing into the race and going well until you detect
some tension THEN STOP. Do not let yourself get excited at all.
End the visualization session and try it again the next day.
Continue this DAILY until you can picture yourself racing and
winning without any stress. If this seems like a lot of work
evaluate just how much you want to win a bike race.

     Visualization is not meant to replace on the bike training
but can make that training pay off in a big way. Eastern European
research has found that athletes improve most quickly if visual
training comprises fifty to seventy-five percent of the total
time spent training! Like any training imagery will only pay off
if you do it regularly and frequently. My French club coach
always used to tell us: believe it and it will become true.

(C) 1989, Roger Marquis (see also Velo-News, 3-91)

------------------------------

Subject: 9.27  Mirrors
From: Jobst Brandt <jbrandt@hpl.hp.com>

> Mirrors are mandatory on virtually every other type of vehicle on
> the road.  Competent drivers/riders learn the limitations of the
> information available from their mirrors and act accordingly.

I suppose the question is appropriate because no one seems to have
a good explanation for this.  In such an event, when there is much
evidence that what would seem obvious is not what is practiced, I
assume there are other things at work.  I for one don't wear glasses
to which to attach a mirror and putting it on a helmet seems a
fragile location when the helmet is placed anywhere but on the head.

These are not the real reasons though, because I have found that when
looking in a head mounted mirror, I cannot accurately tell anything
about the following vehicle's position except that it is behind me.
That is because I am looking into a mirror whose angular position
with respect to the road is unknown.  The rear view mirror in a car
is fixed with respect to the direction of travel and objects seen in
it are seen with reference to ones own vehicle, be that the rear
window frame or side of the car.  I find the image in a head mounted
mirror on a bicycle to be distracting and a source of paranoia if
I watch it enough.  It does not tell me whether the upcoming car is,
or is not, going to slice me.

I additionally I find it difficult to focus on objects when my
eyeballs are distorted by turning them as much as 45 degrees to the
side of straight ahead.  You can try this by reading these words with
your head turned 45 degrees from the text.

I believe these two effects are the prime reasons for the unpopularity
of such mirrors.  They don't provide the function adequately and still
require the rider to look back.  I do not doubt that it is possible to
rely on the mirror but it does not disprove my contention that the
information seen is by no means equivalent to motor vehicle rear view
mirrors to which these mirrors have been compared.  It is not a valid
comparison.

------------------------------

Subject:  9.28 ==> Powerbars NO more ---> homemade -- YES!!!
From:    econrad@teal.csn.org (Eric Conrad)

I don't know about any of you out there in cyber-mtbike-land, but I was
getting tired of buying Powerbars and other nutrition supplements to enhance
my riding.  However, I do understand the benefit of having a quick, nutritious
snack that is full of energy on hand during a ride.

So I asked around and came up with a recipe for Powerbar-like bars that seem
to have a lot of what we need.  I'll place the recipe here on the Usenet for
all to copy, distribute ... [but please don't market them, cause I'll only
kick myself for not doing it first ;-)  ].

Please make them and enjoy them before you think about flaming me.  Trust me,
you'll like them much more than Powerbars, and they're cheaper to make than to
buy their counterpart.

ALSO, PLEASE POST ANY OTHER RECIPES YOU HAVE FOUND THAT HELP BIKING
PERFORMANCE!!!
 

Eric

BARS OF IRON  :-}

1 Cup dark raisins                1 1/2 teaspoon baking powder
1/2 Cup golden raisins            1/2 teaspoon baking soda
1/3 Cup butter or Margarine       1/2 teaspoon salt
1/2 Cup sugar                     1/2 teaspoon ground ginger
1 egg                             1/2 Cup liquid milk
1 1/4 Cup Whole Wheat Flour       1 Cup quick cooking oats
1/4 Cup toasted wheat germ        1 Cup sliced almonds (optional)
1/2 Cup golden molasses (dark is ok also)
1/2 Cup Nonfat dry milk
 

Chop raisins (in food processor if possible).  Cream butter, sugar, molasses &
egg.

Combine flour, dry milk, wheat germ, baking powder, baking soda, salt and
ginger.  Blend into creamed mixture with liquid milk.  Stir in oats, raisins,
and half the almonds (if desired).

Pour into greased 13x9x2 inch pan and spread evenly.  Sprinkle with remaining
almonds (if desired).

Bake at 350 degrees for approx. 30 minutes.  Cool in pan and cut into 1x4 inch
bars.

------------------------------

Subject:  9.29  Lower back pain
From:    "David LaPorte (Biochem)" <david-l@lenti.med.umn.edu>

I'm not a medical expert, but I've had my share of low back pain and I've
learned a few things.  When in doubt, go see a medical professional.

Low back pain is one of the most common problems afflicting humans.  It's
been estimated that about 80% of these problems arise because of poor
posture.  These posture problems occur when we stand but are even more
significant when we sit or ride a bike.  We tend to round up our low
backs, stressing the ligaments and tendons which lie along the spine.  It is
the irritation and inflammation of these ligaments and tendons which leads
to most low back problems.

It is important to remember that back pain results from the sum total of
ALL the stresses your back experiences.  Even if you only experience pain
when you're riding, poor riding posture may not be your only problem.
For example, you may be sitting poorly at a desk all day or lifting boxes
poorly.
 

**Low Back Pain and Posture**

Since posture is the problem, it is also the solution.  Those of us who
suffer from low back pain need to be constantly vigilant.  We need to
maintain some arch in our backs as much as possible.

Sitting is a particular problem.  Most chairs, coaches, car seats, etc
provide little low back support.  You can buy low-back support pads at some
drug stores.  Try them before you buy them because they are not all
comfortable.  Alternatively, you can fold a towel and put it behind your
low back.  The key is to maintain some arch without being uncomfortable.

Position on the bike is also important.  Get your bike fit checked at a
shop that you trust.  You should also work on maintaining a flat back
when riding.  One way to achieve this is to push your belly button toward
the top tube.
 

***Stretching***

Stretching is an important way to achieve flexibility and improve your
posture.  A very useful stretch is to place you hands on you butt and
push your hips forward while standing:

  o
  <\
   /

you should feel this in the front of your hips.  Tight hip flexors
prevent an upright posture.  After a few seconds, arch your back and
slide your hands down the back of your thighs:

  o
  |)
  /

This movement puts the arch in you low back.  You can do this stretch
many times a day.  It is particularly useful to do it periodically when
you have to sit or ride for an extended period of time.

A more potent stretch that can be done a couple of times a day starts
with you lying on your front.  Using your arms, push your shoulders off
the floor.  Don't lift with your back.  Keep your low back as relaxed as
possible.  Let your hips hang down, staying as close to the floor as
possible.

    o
 __/|

This is a powerful stretch and should be started gradually.  Otherwise,
it can do more harm than good.  However, done properly, it can be
enormously helpful.  Over a period of weeks, you should gradually
increase the height you achieve and the time you hold the position.  It
is also less stressful to do this stretch for short periods with a little
rest than for a long period (for example, 3 X 10 sec with 5 sec rest
rather than for 30 sec straight).

Once your back starts to heal, you will probably need to stretch it
deliberately.  This is apparently because of the scar tissue that built
up during healing.  Keep it gentle, especially at first.  You could
easily reinjure your back.  Here's a good one: lie on your back with your
legs straight.  Pull your knees up, grasp your thighs by your hamstrings
and gently pull your knees to your chest.

Stretching the ham strings can also help relieve low back pain.  Tight
ham strings tend to pull the pelvis out of line.  This can stress your
low back.  The problem with most ham string stretches is that they also
tend to stretch the low back by forcing it to round up.  The most
appropriate stretch I know requires the use of a doorway.  Lie in the
doorway with your butt near the wall.   Gently slide your foot up the
wall until you feel the stretch.

   doorway
      |
      |-
      ||
      ||
   |___|____O
           /

Two ways to make the stretch more gentle are (1) bend the lower leg,
keeping only your foot on the floor or (2) move your butt further away
from the wall.  To make the stretch more intense, loop a cord or towel
over your raised foot and gently pull it away from the wall.  As with all
stretches, this shouldn't hurt.
 

***Exercises***

Another key to preventing low back pain is to keep your abdominal muscles
strong.  These muscles help support the back.  Do abdominal crunchers,
not sit ups.  Sit ups emphasize the hip flexors, not the abs, and can be
hard on the back.  Crunchers are done by lying on your back with your
knees bent.  Press your low back into the floor and curl your head and
shoulders off the floor.  Hold for a couple of seconds, then lower back
to the floor.  Repeat until you can't get your shoulder blades off the
floor.  Abs can be worked every day.

Strengthening the low back muscles can also be helpful.  To start, lie on
your front with your arms and legs extended in a straight line with your
body.  Raise your right arm and left leg.  Put them down and raise your
left arm and right leg.  Put them down and continue.  As your back
strength improves, try raising both arms and legs at the same time, arching
your back in a "reverse stomach crunch".  There are, of course, more
powerful back exercises, but they are also more stressful and shouldn't
be considered until your back is 110%.
 

***Medication***

Antiinflamitory medication can be helpful.  Ibuprofen, naproxin and
aspirin are all available without a prescription.  Acetominophen (eg.
Tylanol) is NOT an antiinflamatory.  These drugs are most effective if
they are taken early since inflamation is hard to get rid of once it's
become established.

A danger in antiinflamatory drugs is that they are also pain killers.
Pain is your body's way of telling you that your doing damage.  If you
block the pain signals, you can easily aggravate your injury without
knowing it.

Muscle relaxants are sometime prescribed for back problems.  These should
only be obtained from a physician.
 

***Ice, Heat and Massage***

Ice is a great way to reduce pain and inflamation.  A good way to apply
ice is to freeze water in a paper cup.  Peel the cup back to expose the
ice and then use the cup as a handle while gently rubbing the ice over
the effected area.  Ice is particularly good for the first couple of
days.  Some people find that it's useful to continue ice treatments
beyond that.  Others find that the ice treatments make their backs tight
if they continue beyond a couple of days.

Heat, especially moist heat, can be useful.  However, it should not be
used for a couple of days after injuring your back or after aggravating a
current injury.  Regardless of the timing, if you feel worse during or
shortly after heat treatment, stop doing it.

In the later stages of a back problem, I find that my low back muscles
get tight.  Gentle massage seems to help them relax, promoting the
healing process.  I suspect that massage could make things worse in some
cases, such as when the injury is fresh.
 

***Book***

An excellent book on this subject is "Treat Your Own Back" by Robin
McKenzie, Spinal Publications Ltd., P.O. Box 93, Waikanae, New Zealand
ISBN 0-9597746-6-1.  They use this book at the Low Back Center of the
University of Minnesota Hospital.

------------------------------

Subject: 10  Off-Road

------------------------------

Subject: 10.1  Suspension Stems
From: Brian Lee <brian_lee@cc.chiron.com>

by Brian Lee & Rick Brusuelas, 1994

ABSTRACT:  Discussion of the differences between suspension stems
and suspension forks, and a listing of the pros & cons of suspension
stems.
 
DESCRIPTION:  The suspension stem discussed here is the
Allsop-type, which employs a linkage parallelogram and a spring
mechanism to effect shock-absorption.  Two models on the market
using this mechanism are the Allsop Softride, and  a version
produced by J.P. Morgen, a machinist based in San Francisco.
There is also a version put out by J.D Components of Taiwan
(advertised in Mountain Bike Action), however judging from
illustrations, this unit does not employ the parallelogram design
shared by Allsop & Morgen.  Other Taiwanese models may also exist.
The Girvin-type stem, which uses a simpler hinge and bumper, will
not be directly addressed here, although some of the comments
may also apply.

The Allsop-type suspension stem (suspension stem) works on a
different principal than a telescopic shock fork.  Instead of
only the front wheel moving to absorb shock, a stem allows the
entire front end of the bike to move with obstacles while the
rider's position does not change.

All suspension requires some form of "inertial backstop" to
operate.  A theoretical suspension (stem or fork) loaded with
zero mass will not function regardless of the size of obstacle
encountered.  This is because there is nothing to force the
compression of the spring mechanism.  It is essentially locked
out.

In a fork system, the weight of the bike & rider both provide the
inertial backstop.  In a stem system, the rider's weight on the
handlebars provides the backstop.  Because of this, the two
systems "ride" differently.

Since most of the weight comes from the pressure of the rider's
hands, the stem system encourages a more weight-forward style of
riding.  Or perhaps placing the stem on a frame with a shorter
top tube so the rider's weight is distributed more on the front
end.  (Shortening the front end has also been applied by frame
builders on frames intended for use with suspension forks.  Ex:
Bontrager.)

What does this mean to you and me?  It means the suspension stem
requires a certain amount of the rider's weight to be on it at
all times in order to remain completely active.  For the majority
of riding, it's just fine.  The only difference is in extremely
steep descents, where you are forced to keep the weight back in
order to keep from going over the bars.

In this situation, much less weight is on the bars to activate
the stem.  Further, if one were to encounter a largish rock on
such a descent, what does one do?  The instinctive thing is to
pull back a bit to unweight the front and help the front wheel
over.  This removes all the weight from the stem area, and you
are now riding a rigid bike again.

A fork system is also affected by weight shifts, but not quite to
the extent that a stem is affected, because of the weight of bike
& rider coming through the head tube to be distributed into the
fork.  Even if you were to remove your hands from the bars on a
gnarly descent and hang with butt brushing the rear wheel, you
are still applying weight to the bike through the pedals.

All this, of course, is theoretical and YMMV.  I, for one, am not
always able to react to obstacles coming at me and leave the
front end weighted.  When that happens, I'm very glad I have
suspension.

Now enough theory stuff, here's a summary of the advantages &
disadvantages of suspension stems:

PROs

1)  Lighter than a suspension fork.  This depends on the existing
stem/fork combination.  If the current stem and rigid fork are
heavy, then a suspension fork may be a better choice.  For
example, I've chosen the following items for comparison, as they
represent the lightest and heaviest of commercially available
stems & forks (weights for all stems are for conventional types -
non-Aheadset):

Litespeed Titanium          211g
Ritchey Force Directional   375g
Allsop Stem                 625g
Fat Chance Big One Inch     680g
Tange Big Fork             1176g
Manitou 3                  1360g
Lawwill Leader             1588g

So say you have a Litespeed stem and a Fat Chance fork.  The
combined weight would be 891 g.  Switching to an Allsop would
change the combined weight to 1305 g, while a Manitou 3 would
bring it to 1571 g.  The Allsop has a weight advantage of 266 g
(9.4 oz).

OTOH, if you have a Ritchey stem & Tange Big Fork, the original
weight would be 1551 g.  Allsop stem => 1801 g.  Manitou 3 => 1735
g.  In this case, keeping the boat anchor of a fork and switching
to the Allsop would be a weight penalty of 66 g (2.3 oz.).

Of course, YMMV depending on your original equipment.

2)  Does not affect frame geometry.  A suspension fork
retrofitted to a frame, *not* designed for suspension, raises the
front end - sometimes as much as 1".  This reduces the effective
head angle and slackens the steering, slowing it down.  This is
especially true for smaller sized frames which, with their
shorter wheel base, are affected to a greater degree by the
raising of the head tube.  A suspension stem provides suspension
while preserving the handling of the bike.

3)  Torsionally rigid fork.  Telescopic forks all have a certain
amount of flex to them,  and the sliders are able to move up &
down independently.  This aspect of front  suspension forks has
spawned a new line of suspension enhancing products:  stiffer
fork braces, and bigger, heavier suspension hubs.  All to stiffen
up the fork.  This is  one reason suspension stems are favored by
some riders who ride lots of tight, twisting single track.

4)  No stiction.  Stiction, or static friction, is friction that
exists as the fork sliders rub  against the stanchion tubes.
This friction is an extra force that must be overcome  for a fork
system to activate.  Not a problem on large hits.  But more of a
problem  on small- and medium-size impacts.  Because the stem has
none, the stem responds  better to small, high-frequency bumps
(washboard) than many air-oil forks.

5)  More boing for the buck.  The Allsop stem provides up to 3"
of stiction-free travel,  at a cost of about $250, depending
where you go.  The majority of forks in this  price range only
offer 1" - 2" of travel, and are often heavy, flexy, and fraught
with  stiction.  The fork could be stiffened, but at the
additional cost of a stiffer fork  brace or perhaps a suspension
hub and a rebuilt wheel (e.g. fork brace - $90; hub -  $80;
rebuild - $100.  Plus the original $350 for the fork.  YMMV).

6)  Better "feel".  The stem allows you to have a rigid fork,
which transmits more "information" back to the rider.  This is a
benefit when riding through creeks where you cannot see where
your wheel is.

7)  Less exposed to the environment.  The stem is higher, more
out of the way than suspension forks.  Thus you can ride through
creeks and mud without having to worry about your fork seals, or
about contaminating the innards of the fork.  Even if mud
splashes on a suspension stem, the pivots are less sensitive to
grit than sliders and stanchion tubes.

8)  Ease of maintenance.  There are no seals to replace or
service, no oil to replace, no air pressure to adjust, and no
bumpers to wear out.  An occasional lube of the pivots is all
that is needed.  An extension of this is the ease of initial set
up.  For best results, you have to set suspension (fork or stem)
to react according to your weight and riding style.  With air/oil
forks you may have to change oil, adjust pressure or change
damping settings (if the fork has them).  With bumper forks you
may need to swap out bumper stacks and mix-n-match bumpers until
you get what works for you.  With the stem, the only adjustment
is to increase or decrease the spring tension with an allen
wrench.
 

CONs

1)  No damping.  This is one of the main complaints from
proponents of suspension forks.  The suspension stem will give
way to absorb shock, but the return is not controlled and cannot
be adjusted.  JP Morgen currently makes a suspension stem which
employs oil-damping, but Allsop does not.

2)  Requires adjustment to riding style.  As mentioned above, the
stem requires weight to be applied to it to function.  This is
also one of the complaints applied to the Softride rear
suspension beam.  The flip-side to this, according to riders of
the Beam, is once the adjustment is made to "plant your butt on
the saddle" the ride is extremely comfortable and affords
excellent control by sticking the rear tire to the ground.

3)  Stem "clunks" on rebound.  The feeling is about the same as
suspension bottoming out, except it happens on the rebound.  This
is not as much a problem on the Allsop as on the Morgen stem,
which uses a hard plastic top-out bumper.  This is a subjective
complaint, as some riders claim not to notice it.

4)  Stem not torsionally rigid.  Another trade off.  The stem is
not proof to twisting forces and may be noticeable in hard,
out-of-the-saddle efforts.  Allsop has redesigned the top beam of
their aluminum stem for 1994 to address this problem.  Instead
of the aluminum "dog bone" structure for the top linkage member,
they've substituted a machined aluminum beam, reminiscent of a
cantilever bridge.

SUMMARY:  In my opinion, a suspension stem is an excellent choice
if one is retrofitting an existing bike, which has not been
designed around a suspension fork.  A suspension stem is also a
very good choice if one's primary riding is twisty singletrack,
where you need the sharp, precise steering of a rigid fork.
There are undoubtedly situations for which a stem may not be
ideal, but stems should not be dismissed as a viable form of
suspension.  The best thing to do is to try both types of
suspension if you can, and see what you like better.


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