Sirris F43 CMX Front Fork – Surron LBX | E Ride Pro S / SS 2.0

RIDE IT ONCE. REGRET EVERYTHING ELSE.

The Sirris F43 CMX is the ultimate compact E-Moto fork, engineered for elite control, razor-sharp handling, and unmatched front-end confidence. Race-built with an oversized F43 chassis and CMX-tuned closed cartridge damper, it’s the strongest, most durable, and highest-performance fork for your bike.

Precision Engineering for Elite Performance

• CMX-Tuned Closed Cartridge Damper – Optimized for precise damping, enhanced traction, and stable performance across all terrains

• Tool-Free Compression Adjusters – Nearly 30 clicks of external adjustment without a screwdriver for quick tuning on the fly

• Direct Mount (DM) Ready Stem – Installs effortlessly with your existing stem; no extra parts required

• Drop Clamp Option – Optional 21” wheel fitment by raising the front end 25 mm while maintaining 220 mm travel

• Ultra-Stiff Axle & Brake Mounts – Promotes precise steering and allows caliper/wheel upgrades

• Customizable Triple Clamps – Billet 6061 aluminum, available in black or blue

Specifications

• Architecture: Upside-down fork (USD)

• Travel: 220 mm (drop clamp option adds +25 mm)

• Free Length: 775 mm

• Fork Spacing: 178 mm

• Fork Weight: 4 kg per leg

• Stanchions: Ø43 mm, high tensile steel, hard chrome

• Outer Tubes: Seamless 7050 aluminum, type 3 hard anodized

• Dropouts: 6061 aluminum, type 2 anodized, replaceable caliper mount brackets

• Axle: Ultra-high tensile hard chromed

• Triple Clamps: Billet 6061 aluminum, type 2 anodized, blue or black

• Steer Tube: Seamless 7050 aluminum, type 2 anodized

• Damping: Symmetrical closed cartridge with spring-backed modified IFP

• Rebound: Dual-side high tensile steel spring, adjustable

• Adjusters: External tool-free compression, rebound adjusted with tool

• Seals: NOK MX

• Bushings: Daido MX

• Fork Guards: High-impact PP, 210-degree wraparound

Spring Rate Chart

Choose the CMX tune based on rider weight (without gear; ~15 lbs riding gear included):

• Medium: 140–180 lbs (3.6 / 3.2 left/right)

• Heavy: 180–220 lbs (3.6 / 3.6 left/right)

Bike Fitment

• Surron LBX

• Surron LBS

• E Ride Pro S

• E Ride Pro SS 2.0

The Sirris F43 CMX Fork delivers race-level stiffness, tunability, and precision. Perfect for riders seeking the ultimate upgrade in front-end performance and confidence.