Occasional click/tick sound in 7th gear. Anyone?

[gawarner]

I just assembled the radCity 5 Step through. Everything went well and the bike rides well, except for one small irritating thing. In 7th gear,  hear an occasional click or tick while pedaling. It seems to be occurring randomly. Anyone have any idea what this could possibly be?

[JimInPT]

I think click/tick sounds are usually related to one or more loose spokes, but I doubt it would be related to the chosen gear - my MiniST2's rear wheel ticks a little bit now and then, but it's related to the weight loading - haven't yet found a spoke that actually feels loose, and keep meaning to poke around with it.  Winter gives me a good excuse to wait until the garage isn't so cold anymore......