Then you've unfortunately ended up with a very unfortunate combination of tire and axle.
This proves that the soft tire counteracts the hard axle. Therefore, you should also use a normal hard axle with your "standard" tires .
It's clear that running at high pressure generally isn't as stable, simply because the contact area is somewhat smaller.
In my case, it was only about absorbing the lateral forces that occur during an autocross event.
Gruß Bertil
Skoda 5E5 CZDA + Mini R50 W10 + VW ID.3 + Fiat Ducato 250 + 161 DX
*** Technische Anfragen per PN werden von mir nicht beantwortet! ***