I´m having BIG poblems with th belts skipping during braking and hard acceleration. Anyone who has some tips?

The belts are replaced (They even skipped when they where brand new and after a while). I have tried diffrent settings to the tensioners but nothing helps.

I run 5 cell, spool, bruhless and rubber tires on carpet.

Does your belts skip? If not, how did you fix it?