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PART II
fatigue Is not A Perfectly Predictable
science
Fatigue is not a perfectly predictable science, but
we can give you some general factors to help you
determine how often you need to inspect (or have
your retailer inspect) your bicycle. The more you fit
the “shorten product life” profile, the more frequent
your need to inspect. The more you fit the “lengthen
product life” profile, the less frequent your need to
inspect.
factors that shorten product life:
• Hard, harsh riding style
• "Hits," crashes, jumps, other "shots" to
bike
• High mileage
• Higher body weight
• Stronger, more fit, more aggressive rider
• Corrosive environment (wet, salt air,
winter road salt, accumulated sweat)
• Presence of abrasive mud, dirt, sand,
soil in riding environment
factors that lengthen product life:
• Smooth, fluid riding style
• No "hits," crashes, jumps, other "shots"
to bike
• Low mileage
• Lower body weight
• Less aggressive rider
• Non-corrosive environment (dry, salt-
free air)
• Clean riding environment
Aluminum frame Inspection
1. Clean the bike and remove the wheels.
2. Inspect the whole frame carefully for cracks.
Pay particular attention to the underside of the
downtube where it intersects the headtube
3. Next carefully inspect the area where the
crankset and rear wheel come closest to the right
chainstay, particularly on the innermost part
of the chainstay and the outermost part of the
chainstay. Next look at the welds that join all
of the tubes. Be sure to look at the inside of the
rear triangle or swingarm while the wheel is out,
including the dropouts.
4. Finally check all mounting points such as disc
brake caliper brackets and water bottle and rack
mounts.
figure 21.
ToPTUBe
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Inspect this area for cracking
