Renthal – Front Sprockets - Yamaha - Mini & Youth, including 428 pitch sprockets for the YZ 85, YZ 85LW and 420 pitch grooved gearing for the YZ 65 in 13, 14 and 15 tooth, youth racing rewards smooth gearing more than raw power, and that is what this small, purpose-built group delivers. Each one is machined from hardened steel, and the grooved versions use an open tooth face that lets mud, sand and roost escape rather than pack between chain and sprocket, which is exactly the abuse a mini takes mid-pack on a wet track. Gearing choice changes the whole race for a young rider: a 13 tooth tightens final drive for tight, low-speed tracks and helps the bike drive out of ruts without slipping the clutch, while a 15 tooth calms a peaky two-stroke on long straights so the rider can hold a gear and stay smooth. Short swingarms make chain slack sensitive, so precise pitch keeps tension stable and the chain quiet. Families and race teams keep choosing Renthal because these hold their tooth profile through a long season of motos and practice. On a YZ 85 or YZ 65, gearing sets how hard a young racer has to work the clutch.