EBMX Gold Race Chain & Sprocket Kit

The EBMX Gold Race Chain & Sprocket Kit is a heavy-duty final drive upgrade engineered by EBMX in Australia to handle the massive instantaneous torque of tuned electric dirt bikes. Upgrading to high-power controllers like the EBMX X-9000 or KO Beast V2 will quickly stretch or snap factory non-O-ring chains. This race-proven kit provides bulletproof power transfer, reduced friction, and long-lasting durability.

The kit includes a premium 420-pitch gold-plated O-ring sealed chain (106 links) featuring internal grease seals that lock in factory lubricant while sealing out abrasive trail grit and moisture. The rear sprocket is CNC-machined from ultra-high-strength 7075-T6 aerospace aluminum with a 58-tooth configuration that increases mechanical torque reduction by approximately 20% for aggressive acceleration and steep hill climbing.

The countershaft front sprocket is case-hardened steel (14T), ensuring precise tooth engagement and zero wear against the motor jackshaft output.

Gearing Physics & Trail Benefits: Moving to a 58T rear sprocket increases low-end wheel torque, allowing riders to conquer technical rock climbs and lift the front wheel over obstacles effortlessly.

Chain Tension & Installation: Install the chain with approximately 15mm to 20mm of vertical slack at the midpoint of the swingarm to allow full suspension compression without binding. Always verify that the master link spring clip closed end faces the direction of forward chain rotation.

Frequently Asked Questions:

Q: What is the benefit of a 420 O-ring chain over a non-O-ring chain? A: O-ring seals keep internal lubricant inside pin bushings and seal out dirt and water, extending chain life by 3x to 5x under off-road conditions.

Q: How does a 58T rear sprocket change my bike's gearing? A: A 58T sprocket increases mechanical gear reduction, delivering roughly 20% more low-end wheel torque for faster acceleration and hill climbing.

Q: How do I install the chain master link clip correctly? A: Always install the spring clip with the closed, rounded end facing the direction of forward chain travel to prevent accidental unhooking.

Q: How often should I lubricate an O-ring race chain? A: Clean and apply dedicated O-ring safe chain lube every 3 to 5 rides, avoiding harsh solvent degreasers that degrade rubber O-rings.

Q: Does this kit fit stock Sur-Ron wheel hubs? A: Yes. The 58T rear sprocket features the standard Sur-Ron bolt pattern for a direct bolt-on fit.

Case-Hardened Steel Pinion & Gearing Ratios: The countershaft 14T front sprocket is manufactured from case-hardened alloy steel to resist the instant torque pulses of high-power electric motors. Paired with the 58T rear sprocket, it provides optimal gear reduction for steep hill climbing and technical woods riding, allowing the motor to spin in its peak efficiency RPM band.

Chain Slack Adjustment & Gearing Math: Running a 58-tooth rear sprocket increases chain wrap around the rear hub, requiring a 106-link 420 chain. Adjust the rear axle position until the chain has 15mm to 20mm of vertical play at the midpoint of the swingarm when the suspension is at resting sag, ensuring the chain does not bind under full compression.

O-Ring Internal Lubrication & Sprocket Hardening: High-tensile steel link pins are vacuum-packed with heavy-duty synthetic grease behind rubber O-rings, while the 7075-T6 aluminum rear sprocket is hard-anodized for long tooth life under electric torque.