If the rear was breaking loose at high speed the speedo would show a massive jump in speed, even though you aint accelerating.

We've all done 80mph without moving, have we not?

I agree with the others, gotta be a clutch issue.

 

the only think i can think of if you rev high on the throttle and the rpms go up but the acceleration goes down seems to be a problem with the clutch slipping.

 

When is the last time your have checked your clutch? I have over worked a clutch on the track and warped the steel plates. Installed a EBC race clutch kit and new steel plates talk about night and day.

 

I got it to do it again... Its the damn clutch.
Do you have any good links for better than OEM clutches?

 

Yes,these bikes can get good wheelspin,if tuned right.Mine does.

 

I would bet VERY large amounts of money on clutch... Get that **** checked out while it still moves, puahahaha!