I think limiting rear tyres to Trials or Speedway type is a retrograde step for every era, especially for the Evos and Pre 90s, if they run.
Whats wrong with K70s or the modern equivalent ?? or indeed the tyres that were run, on oil tracks, in the 80s and other eras represented ??
Freaky, the track is hard oil and unless the club rips the track , it will probably stay that way.
I have no problem with loose deco tracks or hard pack oil ones as , BITD you just changed the rear tyre to suit the track you were gonna race on !!
Foss