Bonneville America Forums Forums Technical Forums General Tech 2016 TBA LT front sprocket “rattle”

My 2016 TBA LT has developed a “rattle” that seems to be coming from the front sprocket at exactly 65 mph in 4th gear. Once I shift into 5th, noise goes away. Very annoying, so I bought a new o-ring chain although the bike only has 8,000 on it. Inspected the front sprocket for anything unusual but didn’t see anything that would cause a “rattle”. Installed the new chain per the book, and the noise did go away for the first 50 miles or so, with the new chain, but then came back. I put the bike on my jack and put it in 4th gear, and sure enough at 65 mph indicated, it rattles quite significantly from the sprocket.
Any ideas? Anyone else have this issue? Thanks in advance..

This is a new one to me, I'm afraid.
Did you do any work/ change any parts recently?
E.g. my late 014 LT vibrated at random revs after I'd fitted Metzler 888:s.
Drove me nuts till I threw them away and fitted alternative tyres.

Nut loose? Splines worn? Rubber shot? Bearing on the shaft bad? Any leaks at the shaft? Teeth worn?

As I recall there is counterbore side to the nut that clears the splines. The outer diameter of that is what clamps the sprocket to the shaft. If, for some reason the thickness of the sprocket has changed or the locking washer thickness, you could be loosing the clamp on the sprocket. The nut would still be tight, but would not be squeezing the sprocket against the shoulder of the counter shaft.

Hi - I had mine from factory loosen up on me, the nut was finger loose!!! Boy was that scary!!!