My Nyon works fine in the US. I have no issues at all. They seem to be abandoning the Nyon and heading in a different direction all together with the likes of Kiox which is smaller.
I had the same problem when I got mine. The dealer had not set up the NuVinci correctly. They had not set the rear hub in overdrive mode. There is a good video of it on YouTube by Park Tool.
Hope this helps you. If your bike shop is any good they will be able to follow this video to correct...
