INSPECTION OF THE COMPOSITE PARTS
OF YOUR HUMMINGBIRD
Carbon fibre is a synthetic polymer that is heated to high temperatures until they carbonise.
The result is a black, extremely light and firm fibre, smaller than a human hair with a tensile
strength four times higher than the best steel alloys – at just a quarter of the weight.
The fibres are preimpregnated with a special resin which when cured at high temperature
bonds together all the fibers making the part a single solid composite piece.
Inspect for cracks, broken, splintered or delaminated areas. Any crack is serious. Do not ride
any bicycle or component that has a crack of any size.
Delamination is serious damage. Composites are made from layers of fabric. Delamination
means that the layers of fabric are no longer bonded together.
Undamaged areas will look glossy, shiny or “deep,” as if one was looking into a clear liquid.
Delaminated areas will look opaque and cloudy. The surface shape may change and may have a
bump, a bulge, soft spot, or not be smooth and fair. If you then tap a delaminated area, you will
hear a different sound, usually duller, less sharp.
Either a crack or delamination can cause creaking noises while riding. Think about this noise as
a serious warning signal. A well maintained bicycle will be very quiet and free of creaks and
squeaks. Investigate and find the source of any noise. It may not be a crack or delamination,
but whatever is causing the noise must be fixed before riding.
Do not ride a bicycle or component with any delamination or crack. Riding a delaminated or
cracked frame, fork or other component could lead to complete failure, with risk of serious
injury or death.
If you were involved in a crash, first check yourself for injuries and take care of them as best
you can. Seek medical help if necessary. Next, check your bike for damage. After any crash,
take your bicycle to your local bike shop for a thorough check. All components such as
carbon composites, handlebars, stems, cranksets, brakes etc. which have sustained an impact
must not be ridden until they have been disassembled and thoroughly inspected by a qualified
mechanic.
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