I figured it out.
Mostly I just get tired of the lack of explanations and/or guides. Especially since it in this case goes against the very priciple upon which it is made.
Just a tiny guide on the wheels would be nice :)
About 1,75mm filament being the most common type.. I highly doubt the market is quiet there yet, but it is moving that way for common materials :) I use both sizes, but that is not really important in this case.