sound when walking the bike backwards

[Rema1000]

This summer, my GS has started to produce a sound as I walk it backwards in neutral (to get out of the garage).  The sound is a metallic "tink-tink-tink-tink...", as if you were slowly pulling a chain through a block and tackle.  The sound is only produced when walking the bike backwards. It's not very loud; I can only hear it when I'm not wearing earplugs.  But I don't think that I heard it until midsummer this year.

Sound harmless?

[JamesG]

Your chain is dragging on the centerstand or the engine chain guard.
Even if the chain is properly tightened (you may want to check) when rolled backwards, its the rear sprocket that is pulling the chain, so the bottom run is slack, so it touches easier.

[dorian chapman]

do you wear earplugs when you ride ?
i lvoe hearing the engine, i think i'd go crazy if i rode with earplugs

[zlei]

What you might be hearing is the chain links slapping into place on the front sprocket.

[Rema1000]

I thought "chain tension? but this is practially a brand new chain, and I just put it on... <pause to check maintenance log> oh, I see, 3326 miles ago".   It's gone up from 25mm to 28mm, and looks like it will probably exceed the 30mm specified tolerance at about 4500 miles of service, which sounds about right since the adjustment interval is every 4000 miles.

But at that rate, it looks like I will be out of adjustment room at about 13k miles.  I thought I was taking better care of it than that.