Sirris F43 CMX 220mm Tool-Free LSC Fork | By Sirris Suspension | For E-Ride Pro SS 3.0

Built to Dominate Any Terrain, Any Time

At REV Rides we work with a lot of suspension upgrades, and the Sirris F43 CMX Fork is easily one of the most impressive compact e-moto forks available today. Designed specifically for platforms like the E-Ride Pro SS 3.0, this fork delivers full-size motocross level performance in a chassis optimized for lightweight electric bikes.

The F43 CMX combines an oversized 43mm upside-down race chassis with Sirris’ proprietary CMX tuned closed cartridge damping system. The result is razor sharp handling, incredible front end confidence, and consistent control when riding aggressively on trails, tracks, or rough terrain. With 220mm of suspension travel, tool free compression adjustment, and race grade materials throughout the fork, this is a serious upgrade over stock suspension.

Sirris started with their race-proven F43 platform and resized it specifically for compact electric motos. The 775mm chassis length, oversized stanchions, and billet clamps create a stronger and more planted front end while maintaining the agility these bikes are known for. The design focuses on eliminating flex, improving durability, and delivering predictable suspension performance even when the bike is pushed hard.

Oversized Chassis Designed to Outperform

• 43mm hard chrome stanchions resist flex, dents, and wear

• 7XXX series hard anodized uppers maximize strength and durability

• 775mm extended fork length creates a longer and more stable front end

• 220mm travel provides 20mm more travel than stock suspension

• Billet aluminum triple clamps increase stiffness and reduce twisting

• 178mm fork spacing allows nearly unlimited tire choices

• Direct mount stem compatibility improves cockpit stiffness

• Ultra stiff chromoly race axle increases steering precision and front end feel

• Motorcycle style top cap improves steering bearing tension control

• Replaceable brake mounts and wheel spacers allow brake and wheel upgrades

This design focuses on more than just stiffness. The F43 CMX is built to improve balance, soak up hard impacts, and maintain long term durability for riders pushing higher speeds and rougher terrain.

Race Grade CMX Closed Cartridge Damping

At the core of the fork is the CMX tuned symmetrical closed cartridge damper. This advanced system provides professional level damping performance with independent oil circuits that separate lubrication and damping oil. This design helps maintain consistent performance even during long aggressive riding sessions.

• CMX Compact Motocross Tune designed for aggressive riding

• Symmetrical closed cartridge design delivers fade free damping

• Independent oil circuits isolate damping and lubrication oil

• High flow pistons with fully tunable compression and rebound valving

• Hydraulic bottom out control protects against harsh landings

• Hard anodized internal components reduce wear and increase longevity

• Premium Daido bushings and NOK MX seals ensure smooth operation

The CMX tuning delivers a planted and predictable ride feel. From aggressive trail riding to high speed track laps, the fork stays composed and easy to tune for rider preference.

Tool-Free Compression Adjustment

The F43 CMX features tool free compression adjusters, allowing riders to quickly adjust suspension settings without tools. With nearly 30 clicks of external adjustment, dialing in the fork for different terrain or riding styles is fast and simple.

Direct Mount Stem System

The Sirris steerer tube and motorcycle style top cap system are designed for direct mount stems. This setup improves cockpit stiffness and helps maintain consistent steering bearing torque, similar to larger motocross bikes.

The stock E-Ride Pro stem is not compatible because the Sirris steerer tube cannot be clamped. We recommend using a Warp 9 direct mount stem or the Heavy Hitter Adjustable Billet Display Mount by GritShift.

Optional Drop Clamp for Big Wheel Builds

The optional drop clamp raises the front end an additional 25mm, extending fork length to approximately 800mm. This allows riders to run a 21 inch front wheel while maintaining proper bike balance when paired with longer rear suspension.

Axle and Brake Mount System

• Ultra stiff chromoly axle improves steering precision

• Replaceable caliper mount brackets allow brake upgrades

• Designed for 220mm brake rotor setups

• All Sirris brake brackets are designed for 220mm rotors

Technical Specifications

• Architecture: Upside Down Fork

• Travel: 220 mm

• Free Length: 775 mm

• Extended Length with Drop Clamp: ~800 mm

• Fork Spacing: 178 mm

• Weight: 4 kg per leg

• Stanchions: Ø43 mm high tensile steel, hard chrome

• Outer Tubes: Seamless 7050 aluminum, Type III hard anodized

• Drop Outs: 6061 aluminum, Type II anodized

• Axle: Ultra high tensile hard chromed axle

• Triple Clamps: Billet 6061 aluminum, Type II anodized (Black or Blue)

• Steer Tube: Seamless 7050 aluminum

• Damping: Symmetrical adjustable closed cartridge with modified IFP

• Compression Adjustment: External tool free LSC adjuster

• Rebound: Dual side adjustable

• Seals: NOK MX seals

• Bushings: Daido MX bushings

• Fork Guards: High impact PP wraparound guards

Spring Rate Options

• Medium: 140 to 180 lb rider weight, 3.6 / 3.6 springs

• Heavy: 180 to 220 lb rider weight, 4.0 / 3.6 springs

Rider weight ranges are calculated without riding gear. Approximately 15 pounds of riding gear is factored into the recommended range. Any upgrades such as heavier batteries or controllers should be added to rider weight when selecting spring rates.

CMX Tune Setup Notes

• Factory settings are measured in clicks from the fully closed position

• Back adjusters out from closed position to reach factory settings

• Riders near a weight cutoff may adjust preload to fine tune sag

• Aggressive riders may benefit from moving up one spring class

• Riding style and terrain may require further tuning

Fitment

• E-Ride Pro SS 3.0

Who This Fork Is Perfect For

• E-Ride Pro riders building a race ready or track focused setup

• Trail riders who want maximum front end stability and durability

• High power builds that need true motocross level suspension performance

Fitment: Sirris F43 CMX 220mm Fork | Tool free LSC | for E-Ride Pro SS 3.0

• Eride pro SS 3.0

This product may be compatible with more models than shown above. Please see the product description for full details, or contact us for help with fitment.