Gears crunching when high engine braking

[salibandy]

Hey guys, I seem to have run into an issue. Just today on the way home, I was riding when I heard a loud crunch from my engine. I was turning toward the left so I thought I had left my stand down.

 

It was only when I was downshifting to a lower gear, letting out the clutch and engaging the engine braking at high speeds for each gear that I would hear the same thing; it seems like the gears aren't being engaged properly - they would skip, engage, skip, engage in quick succession and cause crunching sounds and jerkiness.

 

Anyone know what is going on?

 

Mark