I would trim a few seconds off here and there, sometimes you are waiting for the bike to reappear.
A lot of these videos maintain the feel of continuity with a wheel going out of frame on one scene and into frame the next with little delay, to keep a feeling of motion, or at least have some noise of the approaching bike for the same.
Mixing the mechanical and other noises further up at key points can add more intensity as well.
When you brush past the leaves you really want to hear that slap.
I like the fact there are slight pauses prior to the bike appearing in shot, it keeps you guessing as to where it might be off to on those lovely trails...