Just purchased game and license key. I had downloaded the demo and entered the license key and all went as it should. Game runs fine with one bike (Schwaben M2 2018) and the 2 tracks.
I would like to add the Original Piboso Bikes which are, as you know, 4 additional bikes. When I try to add them they do not show in the game. I placed the 5 files (pkz files) in the mods folder located at Documents\PiBoSo\GP Bikes\mods\bikes.
Current game version is "beta 18c".
Why do these bike not display in the game?
Unfortunately they aren't compatible.
There are several mods of the bikes to work in latest beta mainly the 990
I guess you'd need to load the tyres as well if you want to use the old bikes.
I don't think any of them will behave very well since there are quite big changes in how the physics work in the later betas.
Mystic made a great update to one as have I but never uploaded mine.
Ask him about it
The old bikes works. You need to download the tyres