I'm from Germany, I searched a Minibike site, and I found one

I, know, I should use the search button, but I can't write in Dutch.
I'm not really happy whit the original-Tires on my minibike, the original "Xunsheng" Tires are not really round.
When i drive, the minibike is hopping because of that.
edit: my tires are front:90/65-6,5 and rear 110/50-6,5
do your know a good Firm like Pirelli or others which produces such small and good tires ??
The Polini-Minibikes, T mean that they have tires named "Junior" but where can I buy them?
thanks
iko_man
and sorry for my bad English
