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

Built to Dominate Any Terrain, Any Time

At REV Rides we see a lot of suspension upgrades come through the shop, but the Sirris F43 CMX Fork is on another level. This fork was designed specifically for high performance compact e-moto platforms like the E-Ride Pro SR, delivering true motocross level suspension performance in a lightweight electric platform.

The F43 CMX pairs an oversized 43mm race chassis with Sirris’ proprietary CMX tuned closed cartridge damping system. The result is razor sharp handling, incredible front end confidence, and a planted ride feel even when pushing aggressive speeds on rough terrain or jumps. With 220mm of travel, race grade materials, and tool free compression adjustment, this fork completely transforms the way an E-Ride Pro SR handles off road or on track.

Sirris started with their race proven F43 platform and resized it for compact electric motos. The longer 775mm chassis, oversized stanchions, and billet clamps create a front end that is stronger, stiffer, and far more stable than stock forks. Everything about this suspension system is built to eliminate flex, improve balance, and deliver durability for riders who push their bikes hard.

Oversized Chassis Designed to Outperform

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

• 7XXX series hard anodized uppers provide exceptional strength and durability

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

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

• Billet aluminum triple clamps increase stiffness and reduce twisting

• 178mm fork spacing allows nearly unlimited tire choice for dirt or street setups

• Direct mount stem compatibility for improved cockpit stiffness

• Ultra stiff chromoly race axle improves steering precision and control

• Motorcycle style top cap for consistent steering bearing tension

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

It is not just about stiffness. The F43 CMX was engineered to maintain balance and durability under real riding conditions. Riders get a front end that absorbs punishment while staying predictable lap after lap.

Race Grade CMX Closed Cartridge Damping

At the heart of the fork is the CMX tuned symmetrical closed cartridge damper. This advanced system delivers professional level damping performance with separate oil circuits that isolate lubrication and damping oil. That design allows the fork to stay cool, consistent, and predictable during long aggressive rides.

• CMX Compact Motocross Tune designed for high speed off road riding

• True symmetrical closed cartridge for fade free damping performance

• Independent oil circuits separate damping and lubrication oil

• High flow pistons with tunable compression and rebound valving

• Hydraulic bottom out control softens heavy landings and big hits

• Hard anodized internal components reduce wear and increase durability

• Premium Daido bushings and NOK MX seals provide smooth performance and long service life
  

CMX tuning delivers a planted, confidence inspiring ride feel even when riding aggressively. From rough trail riding to high speed track laps, the fork remains consistent and endlessly tunable.

Tool-Free Compression Adjustment

The F43 CMX includes tool free compression adjusters that allow riders to quickly dial in suspension feel without tools. Nearly 30 clicks of external adjustment make it easy to adapt the fork to different terrain or riding styles.

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 keeps steering bearing torque consistent similar to larger motocross bikes.

The stock E-Ride Pro stem is not compatible because the Sirris steerer tube cannot be clamped. We recommend 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 overall 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 brake caliper mount brackets allow caliper 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 race 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, 4.0 / 4.0 springs

• Heavy: 180 to 220 lb rider weight, 4.4 / 4.0 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 additional tuning

Fitment

• E-Ride Pro SR

Who This Fork Is Perfect For

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

• Trail riders who want maximum durability and front end confidence

• High power builds that need true motocross level suspension performance

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

• Eride pro SR

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.