The importance of quality and safety tests is growing
in all segments of the bike market. Reasons for this are predominantly
due to new legal regulations for product liability and safety. The
growing importance of customer satisfaction for brand manufacturers and
the requirements for the communication of objective performance data
for marketing purposes in the high-end bike market, also play a
substantial role.
Out of the numerous quality characteristics
available, the following have proven themselves essential when
evaluating bikes. They apply to what is often colloquially known as
“durability” or “stability”. These four characteristics form the
central essence of EFBe’s testing services:
Fatigue strength,
often also referred to as “service life”: A construction can already
show signs of fatigue after being exerted to comparatively small loads
and torques. I.e. micro-cracks are generated, that develop into visible
macro-cracks, and finally end in a fatigue fracture (= residue break).
This fatigue fracture, which in some cases takes years of use to
develop, can occur suddenly without warning and can lead to potentially
serious accidents. A component has service strength, if it is able to
withstand the loads it would endure throughout its lifespan to a high
probability without developing any cracks or fractures. 100% safety
can, however, not be ensured. Fatigue tests help to analyse the risk of
such fatigue fractures.
Maximum static load: A
component must be able to withstand the heaviest operational loads
without any permanent deformations. Static tests therefore guarantee
that nothing will become permanently deformed under the maximum
permissible load conditions.
Overload behaviour:
If a component is subject to heavier loads than intended by the
manufacturer, it must still, however, behave in a good natured, i.e.
ductile (tough) manner. It should bend to show the excessive load and
not show signs of any sudden brittle fractures. Static overload or Impact
tests can be used to examine the behaviour of a component under excess
load conditions.
Rigidity:
Under normal load, components bend slightly and spring straight back to
their original form when they are unloaded. A component that hardly
bends under a defined load is given a high rigidity value. Rigidity
measurements are therefore used to identify to what extent a component
bends (flexes) under a specific load. Depending from component and load high or low rigidity values (comfort) can be requested.
The first three tests are presenting the base of the bicycle safety standards EN 14764, 14766 and 14781.
