Renthal – Renthal Rear Sprockets - Twinring - Suzuki, including 04-06 RM-Z 250 gearing shared with the 91-09 Kawasaki KX 250/F, 03-05 RM 65 grooved 420 options and 48P sprockets in silver, black and green. Suzuki riders looking past disposable gearing land here, because the Twinring layout answers the one complaint about aluminium sprockets: teeth that hook and stretch a chain long before the rest of the drivetrain is worn. Bolting a steel tooth ring onto a light alloy carrier keeps unsprung rotating weight low so the rear wheel still follows the ground and the engine still revs freely, while the wear surface survives sand, grit and hour after hour of riding. The tooth counts on offer suit riders who want drive out of corners more than top-end speed, which is how most RM and RM-Z owners set up for tracks with tight turns and short straights. Precise machining keeps the ring perfectly concentric with the hub, so chain alignment stays true, drivetrain noise stays down, and throttle inputs translate into traction rather than slop. Riders logging long hours between rebuilds get the most from it, since the steel ring holds its tooth form.