Figure 1:
Clamp bolt perpendicular to radius
Chapter 3: inspection, adjustment, and lubrication
Carbon fiber composite can be damaged by sharp edges or clamping mechanisms that cause a point load, or a high pressure area. Such damage can add to stress fatigue, leading to breakage. Before you install any carbon fiber part, or you attach any component to an existing carbon fiber part, make sure the part is compatible. If you are not sure, consult your Trek dealer. This information is only provided as an explanation of how compatibility is determined.
If the part is used, also make sure the part is in 'New' condition by following the carbon fiber composite inspection procedures.
These procedures apply to any part interfacing a carbon part. As an example, a carbon handlebar interfaces the stem, brake levers, shift levers, and possibly bar-ends. All of the clamps of these parts should be inspected for carbon compatibility. If any part does not pass the inspection, either fix the problem or replace the part.
Make sure the clamp is carbon-friendly. It should apply pressure over the largest possible area. It must draw together smoothly, and not pinch. The clamp bolt must be perpendicular to the radius of the clamped item, and should be as close to the surface of the clamped item as possible (Figure 1).
For a handlebar, do not attach bar-ends that use an internal (expanding) clamp mechanism.
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Figure 1: Clamp bolt perpendicular to radius |
Carbon parts can be crushed by clamping in an incorrect location. To resist the forces of a clamp, the clamp area must be designed for clamping. As an example, clamping bar-ends or triathlon handlebar extensions on some carbon fiber handlebars could crush the handlebar. For another example, clamping the stem to the wrong area of a carbon steerer of a fork could crush the steerer (see the Fork page for more information). If you are not sure if a part or area is designed for clamping, consult your Trek dealer.
With some interfaces of metal parts, grease is used on the clamping surfaces to prevent corrosion. Since carbon does not corrode, grease is not necessary, nor recommended. If grease is applied to a carbon part, the part may slip in the clamp, even at the recommended torque specification.
Visually inspect the edges and surfaces of the interfacing parts for burrs or deformation that might mar the carbon part. With your finger, again check the part. Any roughness or sharp edges could mar the carbon part. If a carbon part is scratched deeply, it could have damage so it should not be used. Refer to the information about carbon fiber inspection.
Carbon parts require special lubrication explained in Carbon Inspection and Use.
