One of the best 50cc geared motors is the Moto Morini AM6.
It is e.g. installed in Italian (Aprilia) and Spanish (Motorhispania, Derbi) mopeds (Supermoto and Enduro stye).
I have this one:
https://www.motorhispania.at/news/detai ... p.up-gruen(notive the seat height of 85-89cm.)
Another European alternative would be KTM/Husaberg/Husqvarna group.
But "ready to race" has its price (3695€ for a tiny Husky TC50).
The K-Pipe is very small too (74cm seat height). More suitable for childs.
I must admit, that I don't really like changing gears (frequently).
A 50cc engine lacks power, you always need to shift.
It''s getting better with 125cc...650cc...
The schakel brommer market in Europe is dying. Scooters are more practical.
Beware of the Chinese. They sometimes carry time-honored (bought-up) names (Kreidler), sometimes the importer (Mash) has come up with something. But there is always Chinese technology behind it.
The Chinese are not even that cheap. My Motorhispania was 1500€ from dealer.