The buzz bolt buzz is not the bolt at all, but the long spacer surrounding it between the frame members.
A wrench on that bolt (nut) may feel rock solid tight, but if the spacer between the frame members is loose enough, it will buzz (sometimes badly). When I tightened mine (the 2d time), I cranked on it with all I had, and it squeaked (not to worry it's tool steel). I believe I had to actually compress the frame members to securely capture that long spacer to stop my buzz (a rattle actually).
When tightening, you need not get a tool on each side, just a wrench or socket on the nut side (right).
If it's not this, a front brake caliper will often make noise (like the little clip holder is loose, or the pin the floating rotors move on needs some lube).
