I never had anything larger than sand. When the bike was in the first few thousand miles, there would be about an pencil eraser size "glob" of the material attached to the plug - but I would never use "chunks" "shavings" "pieces", etc, to describe the metal material.
Now that I have 10k miles, I don't get much at all.

I personally would be concerned about anything larger than sand.

 

Bluesrider
put another 1000 miles and then change primary fluid again.
see what comes out on the drain plug, and also filter your oil to catch any non-ferrus parts.
you should get significantlly less debree this time.

 

Will do Bobber Rider; thanks for the advice. The pieces that i found were way larger than sand for sure. I don't know what it was from, but the bike is running like a champ!!