Well done!  I'm gonna give you the 'needs improvement' first...

1.  Your own shadow in the shot is a deal-breaker for me.  This vid is good, but that's the one fault that really glares.  Other minor items...
2.  The light leaks at 1:05 are a bit much.  Half as much would be better.  Same at 2:04 - less would be more.
3.  I love the slo mo of the right hand turn at 2:11, but you used a lot of footage in your vid from that one camera position.
4.  Cut off the empty frames of the shot at 3:11.  There's nothing there.
5.  When he dumps it at the end and you reply in slo-mo, don't use the slowed-down audio with it.  Let some audio from other normal-speed footage play over it.
6.  One thing that would have really brought me into it more is a couple of quick head shots of the riders close up.  Like when they're putting on gear.  Get some faces in there.  Let the viewer see these guys and make a connection, rather than just anonymous helmet-heads on bikes.

What I really liked:
1.  Good selection for the opening shot, two guys bar-to-bar in the whoops.
2.  Good music selection.
3.  I like the pacing of the edits around the 0:57 mark.
4.  Good cut at 1:45.  It implies a change in the pacing.
5.  I like the slo mo pacing in the middle of the vid with the second music selection.  And the overall length of that segment was right on.
6.  Overall I think it's super well done, and I'm sure your riding buddies enjoy it.  As a former owner of a Honda CR500, a Suzuki Hayabusa, and a dozen bikes before those, I sure liked it.  Don't take my list above too hard, it's a kick ass vid. 
It makes me want to go shoot something like this.