Roll sets from POLINI and MALOSSI are treated with high quality PTFE and can be installed dry. Theoretically. Regardless, due to experience, we recommend rubbing each roll lightly with Vario Grease The advantages are even smoother shifting - even when rolls are no longer perfectly round - longer life for your rolls and better maintenance: when installed dry, black dust collects in the variator and is extremely difficult to remove! If rolls are lightly smeared with grease, they much easier to remove dirt.