Malossi Over Range Variator Kit5112800 fits 13mm small splined cranks5114744 fits reinforced cranks (Smooth unsplined from case and then 13mm tapered at tip)5115823 fits 13mm small splined cranks - Use Kit#2015832 for reinforced cranksMULTIVAR 2000 MHRInnovative features of the new MULTIVAR 2000 MHR speed variators Sliding rails with a new profile New HTROLL rolls Equipped with two roll sets with varying basic weightSteel-alloy hub with hard cadmium insert on the sliding surface, both ground and lappedA wide selection of HTROLL rolls with different basic weights is available for optimal set-upAs to versions for Piaggio engines, rail and roll dimensions were increased and a new roll guide cover was fitted.Technical dataApplication range: 28 to 88 mm in average Ø (useful size on chain sliding surface: 20 to 99.5 mm in Ø)Mobile split pulley made of high silicon grade special alloy, surface treated with hardened chemical nickel Sintered bronze self-lubricating bushingSteel-alloy hub with hard cadmium insert on the sliding surface, both ground and lapped Steel roll guide cover, heat treated and surface burnishedGauged high resistant HTROLL rolls made of special CPT, basic weight marked on one sideDriven split pulley contrast spring made of pre-hardened steel-chrome-silicon, painted in different colours according to the relative K value The Minarelli version includes a fixed vented split pulley made of a high silicon steel alloy and provided with hardened chemical nickel insert. No wonder then if with a variator that features such sophisticated engineering, your scooter suddenly has that extra sprint, a consistency in shifting, a greater mechanical "ease" at high speeds and a constancy in performance you've never experienced before with the original version.