Per John Doe:

but if you want the best, there's only one company.

http://www.heinzmann.de/en

Apparently they are not for sale there.

A lot of bike motors come from China and my experience is that
almost anything from China is iffey: might be OK, might be
junk... even the same make/model may vary greatly. I had one
item where they couldn't even thread a shaft properly and it had
to be replaced.

So, unless you can afford top dollar for something from a
European maker, the firewall between you and the Chinese maker
becomes important.

It's not whether something is going to go wrong or not. Things
*will* go wrong. Instead, it's how the retailer handles it.

I bought a complete eBike conversion kit from one little guy and
got what I'm pretty sure is a bad battery. His only response
was to tell me to ship it to some middleman via hazmat shipping
and see what the middleman says. This guy didn't even have
batteries in stock.

OTOH, I bought a motor from ebikes.ca, had an issue with a noise
from the motor, and they made it right immediately and
painlessly. I would definitely recommend these guys to anybody
they will ship to.
--
PeteCresswell