Specification :

The X85 is a full-carbon crosser designed around disc brakes; 160mm rotors to be specific, with ISO mounts that work with mechanical or hydraulic brakes. And the stays and fork play a part in keeping the braking reliable, as well as offering plenty of room for mud to flow through. The disc-brake choice also gave the folks at Look an idea; build the rear stays with 135mm spacing. This means that you can choose amongst the huge range of 29er mountain bike wheels to further tune your ride to your needs.
    CX is the reason they built the X-85.  The frame is light for a disc-brake ride:1150g for a Medium, and paired with a 550g disc brake fork. The straight 1 1/8" steerer provides a little more comfort in rough terrain. The seat post diameter is 27.2mm, so that a more compliant post can be installed.