TECHNOLOGY STORIES BIKE INFO, GEOMETRY ... - Vintage Trek

A Word About Torque Specifications
118
Torque is a measurement of the tightness of a threaded
fastener such as a screw or bolt, determined by
using a torque wrench. The torque specifications in this
manual are listed to help you determine the correct
tightness of parts and their threaded fasteners. More
than anything, these should be used to make sure you
do not over tighten the fasteners. Applying more than
recommended torque to a fastener does not provide
extra holding power and may actually lead to damage or
failure of a part. For example, over tightening bar ends
can crush a handlebar. Once a part is tight enough to
stay tight and be safe, it rarely does any good to tighten
the part any further.
We offer a range of torque specifications. Similar parts
in different bikes may require different torques due to
slight differences.
There are simple function tests you should perform
to make sure a part is properly tightened. They should
be performed whether a torque wrench was used or
not and will suffice as a test for proper tightness if
you do not have a torque wrench. As an example after
assembling a bike you should determine if a stem is
properly tightened to the fork. Place the front wheel
between your knees and try to rotate the stem by twisting
the handlebars from side to side. If the stem does
not twist, it is properly tightened. While this test is
somewhat subjective, it places a much greater force on
the system than is required of the stem clamping force
in normal riding.
2002 Trek Technical Manual