Can't respond to the person below you, so I'll have to do it here - the EU doesn't actually make many motorcycles, and people who buy them don't want a harley - they want something fast and reliable, not loud and showy.
I would suspect it's a general 6% tarriff on things that haven't been included in a trade deal before, and thanks to WTO rules it'll be the same for Japanese motorbikes as well.
That's what I would've thought too, but in 2017 Harley sold 140k bikes in the US and 40k in Europe. So probably a fraction of the Japanese brands, but definitely a significant portion of Harley's business.
I would suspect it's a general 6% tarriff on things that haven't been included in a trade deal before, and thanks to WTO rules it'll be the same for Japanese motorbikes as well.