From: iglesias@draco.acs.uci.edu (Mike Iglesias)
Newsgroups: rec.bicycles,news.answers
Subject: Rec.Bicycles Frequently Asked Questions Posting  Part 4/4
Date: 7 Apr 92 02:48:37 GMT
Expires: 5 May 1992 00:00:00 GMT
Followup-To: rec.bicycles
Organization: University of California, Irvine

Archive-name: bicycles-faq/part4

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

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

Nutrition and Food

Nutrition  (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.

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

Energy Bar Recipe  (Phil Etheridge  phil@waikato.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)

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

Powerbars  (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.

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

Frames

Frame Stiffness  (Bob Bundy  bobb@ico.isc.com)

As many of you rec.bicycles readers are aware, there have been occasional,
sometimes acrimonious, discussions about how some frames are so much 
stiffer than others.  Cannondale frames seem to take most of the abuse.
The litany of complaints about some bike frames is long and includes
excessive wheel hop, numb hands, unpleasant ride, broken spokes, 
pitted headsets, etc.  I was complaining to a friend of mine about how there
was so much ranting and raving but so little empirical data - to which
he replied, "Why don't you stop complaining and do the measurements
yourself?".  To that, I emitted the fateful words, "Why not, after all,
how hard can it be?".  Following some consultation with Jobst and a few
other friends, I ran the following tests:

The following data were collected by measuring the vertical deflection at
the seat (ST), bottom bracket (BB) and head tube (HT) as a result of 
applying 80lb of vertical force.  The relative contributions of the 
tires, wheels, fork, and frame (the diamond portion) were measured using 
a set of jigs and a dial indicator which was read to the nearest .001 
inch.  For some of the measures, I applied pressures from 20 to 270 lbs 
to check for any significant nonlinearity.  None was observed.  The same 
set of tires (Continentals) and wheels were used for all measurements.  
Note that these were measures of in-plane stiffness, which should be 
related to ride comfort, and not tortional stiffness which is something 
else entirely.

Bikes:

TA - 1987 Trek Aluminum 1200, this model has a Vitus front fork, most 
     reviews describe this as being an exceptionally smooth riding bike

SS - 1988 Specialized Sirus, steel CrMo frame, described by one review as
     being stiff, hard riding and responsive

DR - 1987 DeRosa, SP/SL tubing, classic Italian road bike

RM - 1988 Cannondale aluminum frame with a CrMo fork, some reviewers
      could not tolerate the rough ride of this bike


               TA              SS              DR              RM
           ----------      ----------      ----------      ----------
	   ST  BB  HT      ST  BB  HT      ST  BB  HS      ST  BB  HT
diamond	    1   1   0       2   2   0       2   2   0       1   1   0
fork        3  11  45       3   9  36       4  13  55       3  10  40
wheels      2   2   2       2   2   2       2   2   2       2   2   2
tires      68  52  66      68  52  66      68  52  66      68  52  66
total      74  66 113      75  65 104      76  69 123      74  65 108


What is going on here?  I read the bike mags and this net enough to know 
that people have strong impressions about the things that affect ride 
comfort.  For example, it is common to hear people talk about rim types 
(aero vs. non-aero), spoke size, butting and spoke patterns and how they
affect ride.  Yet the data presented here indicate, just a Jobst predicted,
that any variation in these factors will essentially be undetectable to 
the rider.  Similarly, one hears the same kind of talk about frames, 
namely, that frame material X gives a better ride than frame material Y, that
butted tubing gives a better ride that non-butted, etc.  (I may have even 
made such statements myself at some time.)  Yet, again, the data suggest 
that these differences are small and, perhaps, even undetectable.  I offer
two explanations for this variation between the data and subjective reports
of ride quality.

Engineering:
These data are all static measurements and perhaps only applicable at the
end of the frequency spectrum.  Factors such as frequency response, and 
damping might be significant factors in rider comfort.

Psychology:
There is no doubt that these bikes all look very different, especially the
Cannondale.  They even sound different while riding over rough
roads.  These factors, along with the impressions of friends and reviews
in bike magazines may lead us to perceive differences where they, in fact,
do not exist.

Being a psychologist, I am naturally inclined toward the psychological
explanation.  I just can't see how the diamond part of the frame contributes 
in any significant way to the comfort of a bike.  The damping of the frame 
should be irrelevant since it doesn't flex enough that there is any
motion to actually dampen.  That the frame would become flexible at
some important range of the frequency spectrum doesn't seem likely either.

On the other hand, there is plenty of evidence that people are often very
poor judges of their physical environment.  They often see relationships 
where they don't exist and mis-attribute other relationships.  For example,
peoples' judgement of ride quality in automobiles is more related to the
sounds inside the automobile than the ride itself.  The only way to get
a good correlation between accelerometers attached to the car seat and
the rider's estimates of ride quality is to blindfold and deafen the
rider (not permanently!).  This is only one of many examples of mis-
attribution.  The role of expectation is even more powerful.  (Some even
claim that whole areas of medicine are built around it - but that is 
another story entirely.)   People hear that Cannondales are stiff and,
let's face it, they certainly *look* stiff.  Add to that the fact that
Cannondales sound different while going over rough roads and perhaps
the rider has an auditory confirmation of what is already believed to
be true.  

Unless anyone can come up with a better explanation, I will remain 
convinced that differences in ride quality among frames are more a 
matter of perception than of actual physical differences.

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

Frame materials

[Ed note: I got this information from some of the books I have.  People
in the know are welcome to update this.]

There are several materials that are used to make bicycle frames.  They
are:

  Mild steel - usually used in cheap department store bikes.  Frames 
               made from mild steel are heavy.

  High carbon steel - a higher quality material used in low end bikes.
               Reynolds 500 is an example.

  Steel alloy - lighter and better riding than high-carbon frames.  Reynolds
               501 and Tange Mangaloy are examples.

  Chro-moly -  also called chrome-molybdenum or manganese-molybdenum steel.
               One of the finest alloys for bike frames.  Reynolds 531 and
               Columbus SL and SP are some of the best known brands.

  Carbon fiber - high tech stuff.  Made from space-age materials, frames
               made of this are very light and strong.  Some problems
               have been seen in the connections between the tubes and
               bottom bracket, etc.

  Aluminum -   Light frames, usually with larger diameter tubes. 
               Cannondale is a well-known brand.

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

Bike pulls to one side  (Jobst Brandt  jobst_brandt@hplabs.hp.com)

For less than million dollar bikes this is easy to fix, whether it corrects
the cause or not.  If a bike veers to one side when ridden no-hands, it
can be corrected by bending the forks to the same side as you must lean
to ride straight.  This is done by bending the fork blades one at a time,
about 3 mm.  If more correction is needed, repeat the exercise.

The problem is usually in the forks although it is possible for frame
misalignment to cause this effect.  The kind of frame alignment error
that causes this is a head and seat tube not in the same plane.  This
is not easily measured other than by sighting or on a plane table.
The trouble with forks is that they are more difficult to measure even
though shops will not admit it.  It takes good fixturing to align a
fork because a short fork blade can escape detection by most
measurement methods.  Meanwhile lateral and in-line corrections may
seem to produce a straight fork that still pulls to one side.
However, the crude guy who uses the method I outlined above will make
the bike ride straight without measurement.  The only problem with
this is that the bike may pull to one side when braking because the
fork really isn't straight but is compensated for lateral balance. 

This problem has mystified more bike shops because they did not recognize
the problem.  Sequentially brazing or welding fork blades often causes
unequal length blades and bike shops usually don't question this dimension.
However, in your case I assume the bike once rode straight so something
is crooked

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

Frame repair  (David Keppel  pardo@cs.washington.edu)

(Disclaimer: my opinions do creep in from time to time!)

When frames fail due to manufacturing defects they are usually
replaced under warranty.  When they fail due to accident or abuse
(gee, I don't know *why* it broke when I rode off that last
motorcycle jump, it's never broken when I rode it off it before!)
you are left with a crippled or unridable bike.

There are various kinds of frame damage that can be repaired.  The
major issues are (a) figuring out whether it's repairable (b) who
can do it and (c) whether it's worth doing (sometimes repairs just
aren't worth it).

Kinds of repairs: Bent or cracked frame tubes, failed joints, bent
or missing braze-on brackets, bent derailleur hangars, bent or
broken brake mounts, bent forks, etc.  A frame can also be bent out
of alignment without any visible damage; try sighting from the back
wheel to the front, and if the front wheel hits the ground to one
side of the back wheel's plane (when the front wheel is pointing
straight ahead), then the frame is probably out of alignment.


* Can it be repaired?

Just about any damage to a steel frame can be repaired.  Almost any
damage to an aluminum or carbon fiber frame is impossible to repair.
Titanium frames can be repaired but only by the gods.  Some frames
are composites of steel and other materials (e.g., the Raleigh
Technium).  Sometimes damage to steel parts cannot be repaired
because repairs would affect the non-steel parts.

Owners of non-steel frames can take heart: non-steel frames can
resist some kinds of damage more effectively than steel frames, and
may thus be less likely to be damaged.  Some frames come with e.g.,
replacable derailleur hangers (whether you can *get* a replacement
is a different issue, though).  Also, many non-steel frames have
steel forks and any part of a steel fork can be repaired.

Note: For metal frames, minor dents away from joints can generally
be ignored.  Deep gouges, nicks, and cuts in any frame may lead to
eventual failure.  With steel, the failure is generally gradual.
With aluminum the failure is sometimes sudden.

Summary: if it is steel, yes it can be repaired.  If it isn't steel,
no, it can't be repaired.


* Who can do it?

Bent derailleur hangers can be straightened.  Indexed shifting
systems are far more sensitive to alignment than non-indexed.  Clamp
an adjustable wrench over the bent hangar and yield the hangar
gently.  Go slowly and try not to overshoot.  The goal is to have
the face of the hangar in-plane with the bike's plane of symmetry.

Just about any other repair requires the help of a shop that builds
frames since few other shops invest in frame tools.  If you can find
a shop that's been around for a while, though, they may also have
some frame tools.


* Is it worth it?

The price of the repair should be balanced with

 * The value of the bicycle
 * What happens if you don't do anything about the damage
 * What would a new bike cost
 * What would a new frame cost
 * What would a used bike cost
 * What would a used frame cost 
 * What is the personal attachment

If you are sentimentally attached to a frame, then almost any repair
is worth it.  If you are not particularly attached to the frame,
then you should evaluate the condition of the components on the rest
of the bicycle.  It may be cheaper to purchase a new or used frame
or even purchase a whole used bike and select the best components
from each.  For example, my most recent reconstruction looked like:

 * Bike's estimated value: $300
 * Do nothing about damage: unridable
 * Cost of new bike: $400
 * Cost of new frame: $250+
 * Cost of used bike: $200+
 * Cost of used frame: N/A
 * Cost of repair: $100+
 * Personal attachment: zip

Getting the bike on the road again was not a big deal: I have lots
of other bikes, but I *wanted* to have a commuter bike.  Since I
didn't *need* it, though, I could afford to wait a long time for
repairs.  The cost of a new bike was more than I cared to spend.
It is hard to get a replacement frame for a low-cost bicycle.  I
did a good bit of shopping around and the lowest-cost new frame
that I could find was $250, save a low-quality frame in the
bargain basement that I didn't want.  Used frames were basically the
same story: people generally only sell frames when they are
high-quality frames.  Because the bike was a road bike, I could have
purchased a used bike fairly cheaply; had the bike been a fat-tire
bike, it would have been difficult to find a replacement.  The cost
of the frame repair included only a quick ``rattlecan'' spray, so
the result was aesthetically unappealing and also more fragile.  For
a commuter bike, though, aesthetics are secondary, so I went with
repair.

There is also a risk that the `fixed' frame will be damaged.  I had
a frame crack when it was straightened.  I could have had the tube
replaced, but at much greater expense.  The shop had made a point
that the frame was damaged enough that it might crack during repair
and charged me 1/2.  I was able to have the crack repaired and I
still ride the bike, but could have been left both out the money
and without a ridable frame.


* Summary

Damaged steel frames can always be repaired, but if the damage is
severe, be sure to check your other options.  If the bicycle isn't
steel, then it probably can't be repaired.

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

Frame Fatigue  (John Unger  junger@rsg1.er.usgs.gov)

I think that some of the confusion (and heat...) on this subject
arises because people misunderstand the term fatigue and equate it
with some sort of "work hardening" phenomena.

By definition, metal fatigue and subsequent fatique failure are
well-studied phenomena that occur when metal (steel, aluminum,
etc.) is subjected to repeated stresses within the _elastic_ range
of its deformation. Elastic deformation is defined as deformation
that results in no permanent change in shape after the stess is
removed. Example: your forks "flexing" as the bike rolls over a
cobblestone street.

	(an aside... The big difference between steel and aluminum
	as a material for bicycles or anything similar is that you
	can design the tubes in a steel frame so that they will
	NEVER fail in fatigue. On the other hand, no matter how
	over-designed an aluminum frame is, it always has some
	threshold in fatigue cycles beyond which it will fail.)

This constant flexing of a steel frame that occurs within the
elastic range of deformation must not be confused with the
permanent deformation that happens when the steel is stressed beyond
its elastic limit, (e. g., a bent fork). Repeated permanent
deformation to steel or to any other metal changes its strength
characteristics markedly (try the old "bend a paper clip back and
forth until it breaks" trick).

Because non-destructive bicycle riding almost always limits the
stresses on a frame to the elastic range of deformation, you don't
have to worry about a steel frame "wearing out" over time.

I'm sorry if all of this is old stuff to the majority of this
newsgroup's readers; I just joined a few months ago. 

I can understand why Jobst might be weary about discussing this
subject; I can remember talking about it on rides with him 20 years
ago....

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

Injuries

Road Rash Cures  (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. 

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

Knee problems   (Roger Marquis  marquis@qal.berkeley.edu)

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.