Adding to Damien's comments, I'm wondering if ANY motorized bike parts are even available in Europe, their laws being FAR more restrictive than anything even Commachussetts, Commieyork, Commiefornia or Commawaii can come up with.
Our friend in Svea Rike may have no choice but to buy fom the US, in which case he will face PROHIBITIVE shipping costs AND import duties.
Example: I used to send Yuletide gifts to a friend of mine in Austria, but, somehow, Brexit put a stop to that, because now, he would have to PAY import duties - for a gift - that far exceed the value of the gift, no matter how much I lowball the value on the customs form.
Not sure what Brexit - the politically theoretical detachment of Little Pakistan from Eurabia - has to do with a package sent from the US to Austria, but there you have it.....