How to create a carbon fibre shader

Think of the Carbon fibre material as two layers. First the fibre layer and then the glossy coating layer.

For the fibers layer connect a fractal with Repeat UV 0.005 and 16 to a Cloth U color
and a fractal with Repeat UV 16 and 0.005 to V Color.
Set the Color Gain of the fractals to a mid blue grey color.
Set the U and V Width of the Cloth texture to 1 and the rest of the values to 0.
Connect the Cloth to a Anisotropic shader with a dark grey specular color.
Connect the Cloth to the Anisotropic as bumpmap with a very small bumpvalue like 0.02.

For the coating layer create a phong shader with black color and a mid bluish grey Specular color.
Set the reflectivity to somewhere in the range of 0.1 to 0.3 depending on the effect you want.
In this example I used a Environment crome texture for Reflected color
but if you have a modelled environment that should be enough.

Connect the Anisotropic shader and the blinn shader to a plusminus average node
and then to outcolor of a surface shader.
(You could use the mix8layer MR shader instead of the plusminus average and surface shader if you like.)

Good luck!