Handleiding Burley Bicycle (pagina 23 van 27) (Engels)

632563

Verklein

Vergroot

Pagina terug

1/27

Pagina verder

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 in

bent, buckled or folded metal.

It is now common for the main frame to be made of metal and the fork of carbon ﬁber.

See Section B, Understanding composites below. The relative ductility of metals and

the lack of ductility of carbon ﬁber means that in a crash scenario you can expect some

bending or bucking in the metal but none in the carbon. Below some load the carbon

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.

Burley Bicycle Handleiding

Hulp nodig? Stel uw vraag in het forum

Misbruik melden

Product:

Spelregels forum

Abonneren

Ontvang uw handleiding per email

Stel vragen via chat aan uw handleiding

Uw handleiding is per email verstuurd. Controleer uw email

Er is een email naar u verstuurd om uw inschrijving definitief te maken.

U heeft geen emailadres opgegeven

Uw vraag is op deze pagina toegevoegd

Info