Giant momentum Anleitung Seite 35

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 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.
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