I have 650 miles on my 2014 S.G.S. and have been wearing a full face the whole time. Today w/Half helmet I hear it clunking when I give it gas or let off the gas.
I did a search before post but found more after. I believe this to be normal. It sounds like a car or truck with a bad U joint.

 

The rear belt sprocket has a built in 'slop' designed to soften driveline loading and unloading. I would say 'normal'

 

I'd say abby normal,but I haven't ridden the bike. If my drive line had slop in it,I'd be checkin' it out.

 

junk primary drive setup, mine does it also. my 92 heritage is smooth as can be. no noise what so ever. this new stuff is way noisy than the older bikes.

 

My 2004 (the red one) is totally quiet.

 

What that John Deere do in that department?

 

Nothing runs like a Deere.