Went out today for a bit of a drive round but came home early.
When I got to 55mph +- a few mph there is a horrible kind of grating/rumbling noise.
As soon as you go below 50mph the noise dissapears.
I'll take a look soon and report back, maybe I drove over some green peace Liberal do gooder.

Hmmm. Try going 25 MPH in low range and see of it does that. That answer will narrow it down.

[2015 Z Force 800 53/Trail EPS]

Many of us have had the heat shield that the front exhaust pipe travels through make contact with the piping in the spring area at different speeds or conditions making all kids of different noises. Mine sounded like it was about to come apart..thought I had lost the engine. Just took some adjustment with a tire iron. Something to check anyway. Check the engine mounts too...and the rubbers.