Gk plus are a stiff tire. I just replaced my wife’s GK slicks with the slick plus. She had around 5000kms, no pinctures on the regular ones, but we’re off on a 10 day tour so thought we’d upgrade the puncture protection for that. They went on to her rims fine but I wouldn’t want to try and get them on a tighter rim.
Gk plus are a stiff tire. I just replaced my wife’s GK slicks with the slick plus. She had around 5000kms, no pinctures on the regular ones, but we’re off on a 10 day tour so thought we’d upgrade the puncture protection for that. They went on to her rims fine but I wouldn’t want to try and get them on a tighter rim.