So my bike started making a noise I've never heard before the other day. Its a kinda a metal on metal noise or a rattling. High pitched, I dunno how else to describe it. It happens when my RPMs are up and I need to shift up OR if I shift up early and ride in a gear up, then it is almost constant. Anyone with any clues? I can't pinpoint where its coming from since I'm riding when I hear it but it is driving me insane and I'm worried about what it could be. Thanks.

2008 Speedy, AI removed, DIY airbox destruction with K&N filters, spectres, re-jetted and "custom" rattle can paint job.