Modern Vespa

I bought a brand-new Vespa Primavera in July 2022 (manufactured in 2022). My back wheel started clicking around October. My attention was drawn to the sound when the bike was pushed with its engine off.

In November, I took the bike to a Vespa dealer for a service and to investigate the clicking issue. Initially, they thought it might be the gearbox and that might need to be replaced. When I returned the bike to the dealer in January, my mechanic told me the gearbox was fine and the clicking had ceased. They were completely baffled by it and had no idea what could have caused the sound.

The clicking sound has returned, but this time it's a bit different. The sound is the same and comes from the same area. I have noticed the clicking occurs when I use the back break in favour of the front break. This is more noticeable when I'm sitting on my bike with my full weight on it.

Any theories ??

My guess would be something in the rear brake drum. Was the rear brake inspected by the dealer?

Does the clicking sound like it's once per revolution of the rear wheel, or is it more or less frequent than that?

Dumb-ass theory: is there a stone caught in the treads of a tire?

Thank you for you reply.

The dealer inspected the breaks and he said said it was fine.

Yes. rear wheel clicks once per revolution.

Which leads me to believe there's something about the wheel, not the transmission.

Is something rubbing on the wheel or tire?