Electra Bicycle - Manual (Page 24)

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appropriate for how and where you use your bike.
For your safety, understanding and communication with your dealer, we
urge you to read this Appendix in its entirety. The materials used to make
your bike determine how and how frequently to inspect.
Ignoring this WARNING can lead to frame, fork or other component
failure, which can result in serious injury or death.
A. Understanding metals
Steel is the traditional material for building bicycle frames. It has good
characteristics, but in high performance bicycles, steel has been largely replaced
by aluminum and some titanium. The main factor driving this change is interest
by cycling enthusiasts in lighter bicycles.
Properties of Metals
Please understand that there is no simple statement that can be made that
characterizes the use of different metals for bicycles. What is true is how the
metal chosen is applied is much more important than the material alone. One
must look at the way the bike is designed, tested, manufactured, supported along
with the characteristics of the metal rather than seeking a simplistic answer.
Metals vary widely in their resistance to corrosion. Steel must be protected
or rust will attack it. Aluminum and Titanium quickly develop an oxide film that
protects the metal from further corrosion. Both are therefore quite resistant to
corrosion. Aluminum is not perfectly corrosion resistant, and particular care must
be used where it contacts other metals and galvanic corrosion can occur.
Metals are comparatively ductile. Ductile means bending, buckling and
stretching before breaking. Generally speaking, of the common bicycle frame
building materials steel is the most ductile, titanium less ductile, followed by
aluminum.
Metals vary in density. Density is weight per unit of material. Steel weighs 7.8
grams/cm3 (grams per cubic centimeter), titanium 4.5 grams/cm3, aluminum 2.75
grams/cm3. Contrast these numbers with carbon fiber composite at 1.45 grams/
cm3.
Metals are subject to fatigue. With enough cycles of use, at high enough loads,
metals will eventually develop cracks that lead to failure. It is very important that
you read The basics of metal fatigue below.
Let’s say you hit a curb, ditch, rock, car, another cyclist or other object. At any
speed above a fast walk, your body will continue to move forward, momentum
carrying you over the front of the bike. You cannot and will not stay on the bike,
and what happens to the frame, fork and other components is irrelevant to what
happens to your body.
What should you expect from your metal frame? It depends on many complex
factors, which is why we tell you that crashworthiness cannot be a design criteria.
With that important note, we can tell you that if the impact is hard enough the fork
or frame may be bent or buckled. On a steel bike, the steel fork may be severely
bent and the frame undamaged. Aluminum is less ductile than steel, but you can
expect the fork and frame to be bent or buckled. Hit harder and the top tube may
be broken in tension and the down tube buckled. Hit harder and the top tube may
be broken, the down tube buckled and broken, leaving the head tube and fork
separated from the main triangle.
When a metal bike crashes, you will usually see some evidence of this ductility
Appendix B
The lifespan of your bike and its components
1. Nothing Lasts Forever, Including Your Bike.
When the useful life of your bike or its components is over, continued use is
hazardous.
Every bicycle and its component parts have a finite, limited useful life. The
length of that life will vary with the construction and materials used in the
frame and components; the maintenance and care the frame and components
receive over their life; and the type and amount of use to which the frame and
components are subjected. Use in competitive events, trick riding, ramp riding,
jumping, aggressive riding, riding on severe terrain, riding in severe climates,
riding with heavy loads, commercial activities and other types of non-standard
use can dramatically shorten the life of the frame and components. Any one or a
combination of these conditions may result in an unpredictable failure.
All aspects of use being identical, lightweight bicycles and their components
will usually have a shorter life than heavier bicycles and their components. In
selecting a lightweight bicycle or components you are making a tradeoff, favoring
the higher performance that comes with lighter weight over longevity. So, If you
choose lightweight, high performance equipment, be sure to have it inspected
frequently.
You should have your bicycle and its components checked periodically by
your dealer for indicators of stress and/or potential failure, including cracks,
deformation, corrosion, paint peeling, dents, and any other indicators of potential
problems, inappropriate use or abuse. These are important safety checks and
very important to help prevent accidents, bodily injury to the rider and shortened
product life.
2. Perspective
Today’s high-performance bicycles require frequent and careful inspection
and service. In this Appendix we try to explain some underlying material science
basics and how they relate to your bicycle. We discuss some of the trade-offs
made in designing your bicycle and what you can expect from your bicycle; and
we provide important, basic guidelines on how to maintain and inspect it. We
cannot teach you everything you need to know to properly inspect and service
your bicycle; and that is why we repeatedly urge you to take your bicycle to your
dealer for professional care and attention.
WARNING: Frequent inspection of your bike is important to your
safety. Follow the Mechanical Safety Check in Section 1.C of this
Manual before every ride.
Periodic, more detailed inspection of your bicycle is important. How
often this more detailed inspection is needed depends upon you.
You, the rider/owner, have control and knowledge of how often you
use your bike, how hard you use it and where you use it. Because your
dealer cannot track your use, you must take responsibility for periodically
bringing your bike to your dealer for inspection and service. Your
dealer will help you decide what frequency of inspection and service is