Description
SIRRIS F43 CMX TUNE
Bike Fitment:
- Surron LBX
- Surron LBS
- Zero XB
DOMINATE THE TRACK
The Compact Motocross Tune F43 is an unapologetic race fork, built for elite-level racers chasing podiums—but it's just as powerful in the hands of everyday rippers looking to level up. Razor-sharp when you push it, forgiving when you need it. This is the ultimate performance upgrade.
FULL SPEED. FULL CONTROL. NO COMPROMISE.
The CMX Tune is purpose-built for the high-speed demands of the lightweight e-moto class—engineered to dominate any terrain, any time, anywhere. Whatever you throw at it, it’s ready.
SPRING RATE CHART:
TOOL-FREE COMPRESSION ADJUSTERS
NEW FOR CMX — Allows for quick compression adjust without a screwdriver.
Enjoy nearly 30 clicks of quick external adjustability.
DIRECT MOUNT STEM
DM READY — New CMX fork is designed with a Direct Mount (DM) setup, so the stem you’re already using will bolt right up—no hassle, no extra parts.
DROP CLAMP OPTION
BIG WHEEL OPTIONAL — Allows for fitment of 21” wheel by raising the front end an additional 25mm while retaining 220mm travel. (Raising the front end maintains balance of the bike if paired with a longer shock that raises the rear)
NEW AXLE & BRAKE MOUNTS
ULTRA STIFF AND CONFIGURABLE — Axle and drop out assembly promotes front end feel and steering precision. Replaceable caliper mount brackets allow for caliper upgrades.
FORK SPECS:
Architecture
Upside down fork
Travel
220 mm
Free length
775 mm
(drop clamp option adds another 25mm of extended length)
Fork Spacing
178 mm - allows for unlimited tire choice (dirt or street)
Fork weight
4 kg per leg (driven by sturdy construction required for the forces and speeds encountered when pushing these bikes to their limits without compromising performance)
Stanchions
Ø43, high tensile steel with hard chrome
Outer tubes
Seamless 7050 aluminum, type 3 hard anodized coating
Drop outs
6061 aluminum, type 2 anodized coating
Replaceable caliper mount brackets allow for caliper and wheel upgrades
Axle
Ultra-high tensile hard chromed axle increases steering precision and confidence
Triple clamps
Billet 6061 aluminum, type 2 anodized coating
Optional drop clamp allows for 21” front wheel conversion
Steer tube
Seamless 7050 aluminum, type 2 anodized coating
Damping
Symmetrical, adjustable closed cartridge with spring backed modified IFP
Damper bodies
Seamless 7050 aluminum, type 3 hard anodized coating
Rebound
Dual side high tensile steel spring, adjustable
Adjusters
External tool-free compression, rebound adjustment
(rebound adjusted using tool)
Seals
NOK MX seals
Bushings
Daido MX bushings
Guards
High impact PP, 210-degree wraparound
