Sirris CMX Fork for E Ride Pro, Ventus, Talaria, Zero XB, Surron LBX

The Sirris F43 CMX is the most advanced compact eMoto fork available — period. Engineered for elite-level performance, the CMX fork brings a race-proven chassis, ultra-planted ride feel, and adjustable closed cartridge damping to bikes like the E Ride Pro SR, SS 3.0, Talaria Sting MX5, Surron Light Bee X, and Zero XB.

Whether you’re racing hard enduro, hitting MX tracks, or just want the most confidence-inspiring front end possible, this fork changes everything.

Note: ECR ships each Sirris F43 CMX fork "built to order" and tuned specifically for each rider. 

Spring Rates

• Medium Tune (140–180 lb rider weight)

• Heavy Tune (180–220 lb rider weight)
  (Based on rider weight without gear. Add 15 lbs for gear, and account for accessories like upgraded batteries.)

Key Features

• CMX-Tuned Damper: Closed cartridge design with separate damping and lube oil paths for fade-free performance.

• Oversized 43mm Stanchions: Hard chrome, high-tensile steel for maximum front-end stiffness and durability.

• Travel: 220mm of fully usable suspension travel.

• Fork Length: 775mm standard (800mm with drop crown).

• Clamp Options: Choose standard or drop clamp for taller stance and 21” front wheel fitment.

• Tire Clearance: 178mm fork spacing fits nearly any tire — dirt or street.

• Direct Mount Stem Compatible: Improved clamping and steering bearing preload with motorcycle-style top cap.

• Replaceable Brake Mounts: Configure for different calipers or future bikes with swappable 220mm mount brackets.

• Ultra-Stiff Axle: Custom chromoly axle for enhanced steering precision.

• Tool-Free Compression Adjusters: Fine-tune your ride without tools.

• NOK MX Seals & Daido Bushings: Long life and smooth action, even under pressure.

Chassis Specs

• Fork Style: USD (Inverted)

• Length: 775mm (800mm with drop crown)

• Travel: 220mm

• Offset: 25mm

• Weight: 4kg per leg

• Stanchions: Ø43mm, hard chrome

• Lowers: Seamless 7050 aluminum, hard anodized

• Dropouts: 6061 aluminum, replaceable caliper brackets

• Axle: Ultra-high tensile chromoly, hard chromed

• Triple Clamps: Billet 6061 aluminum (Black or Blue)

• Steerer Tube: 7050 aluminum, anodized

• Brake Compatibility: 220mm rotors only

• Guard Style: 210° high-impact wraparound

Damping & Tuning

• Damping System: Symmetrical closed cartridge

• Rebound: Adjustable, tool-based

• Compression: Tool-free external adjusters

• Hydraulic Bottom-Out: Integrated

• Internal Finish: 7XXX-series, hard-anodized

Installation Notes

• The CMX fork requires a Direct Mount stem — stock E-Ride Pro stems will not fit.

• We recommend the Warp 9 Direct Mount or GritShift Heavy Hitter Adjustable Mount.

• All versions use 220mm rotor mounts.

• Choose Drop Clamp version for 21" wheel compatibility or a taller front end stance.

Warranty & Shipping

• 1-Year Warranty by Sirris Suspension

• Ships pre-assembled and custom tuned for selected rider weight

Rear Shock Pairing:

We highly recommend pairing your F43 CMX Fork with the EXT Arma shock. 

For additional tuning specs, please note the following in the notes at checkout when selecting your fork settings:

• Type of Riding: Please indicate the terrain you ride your Ultra Bee (MX, Singletrack, Desert, etc.)

• Skill Level: Please indicate rider skill level/race class (Beginner, Novice, Expert, Pro)
  

Fitment

• E Ride Pro SR

• E Ride Pro SS 3.0

• Talaria Sting MX5

• Surron Light Bee X

• Zero XB