{"product_id":"sirris-f43-cmx-tune-220mm-fork-tool-free-lsc-altis-sigma-special-order","title":"Sirris F43 CMX Tune 220mm Fork | Tool free LSC | Altis sigma (Special Order)","description":"\u003ch1\u003eSirris F43 CMX 220mm Tool-Free LSC Fork | Altis Sigma\u003c\/h1\u003e\n\u003ch2\u003eBuilt to Push the Altis Sigma Further\u003c\/h2\u003e\n\u003cp\u003eAt REV Rides we see riders pushing the Altis Sigma well beyond what the stock suspension was originally designed for. Once you start adding power upgrades, riding rough terrain harder, hitting larger jumps, or building a dedicated off-road machine, suspension quickly becomes one of the most noticeable limitations. The Sirris F43 CMX was designed for riders who want true motocross-level front suspension performance on their compact e-moto setup.\u003c\/p\u003e\n\u003cp\u003eThe F43 CMX combines an oversized 43mm upside-down race chassis with Sirris' proprietary CMX tuned closed cartridge damping system. The result is a front end that feels stronger, more planted, and more precise when speeds increase and terrain gets rough.\u003c\/p\u003e\n\u003cp\u003eFor riders building serious Altis Sigma setups, the improvement is immediate. You gain better steering precision, reduced chassis flex, improved impact absorption, and a more predictable feel through rough sections.\u003cbr\u003e\u003cbr\u003e\u003cmeta charset=\"utf-8\"\u003e\u003c\/p\u003e\n\u003ch2\u003eImportant Altis Sigma Fitment Notes\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eThis is a special order item and requires contacting the REV Rides team before purchase to get you this set up just for you.\u003c\/strong\u003e This setup requires modifications and is intended for riders building more aggressive Altis Sigma setups. Please review all installation notes before ordering.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eSpecial order item currently only, contact REVRides.com\/contact before purchasing\u003c\/li\u003e\n\u003cli\u003eRequires drilling and tapping of certain things\u003c\/li\u003e\n\u003cli\u003eRequires modification of dust seals\u003c\/li\u003e\n\u003cli\u003eRequires a different handlebar clamp setup\u003c\/li\u003e\n\u003cli\u003eRequires a different headlight mount\u003c\/li\u003e\n\u003cli\u003eCreates a noticeably stiffer overall front-end setup compared to stock\u003c\/li\u003e\n\u003cli\u003eRecommended for experienced builders or riders performing larger custom builds we suggest a professional to do these modifications \u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cbr\u003e\u003c\/h2\u003e\n\u003ch2\u003eOversized Chassis Designed to Outperform\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e43mm hard chrome stanchions\u003c\/strong\u003e resist flex, dents, and wear\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e7XXX series hard anodized uppers\u003c\/strong\u003e maximize strength and durability\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e775mm extended fork length\u003c\/strong\u003e creates a more planted front end\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e220mm travel\u003c\/strong\u003e delivers additional suspension capability over many stock compact e-moto forks\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLightweight billet aluminum clamps\u003c\/strong\u003e reduce twisting under load\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e178mm fork spacing\u003c\/strong\u003e opens tire options for dirt and street setups\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDirect mount stem compatibility\u003c\/strong\u003e improves steering feel and cockpit rigidity\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUltra-stiff chromoly axle\u003c\/strong\u003e increases front-end precision\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMotorcycle-style top cap system\u003c\/strong\u003e improves steering bearing consistency\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplaceable brake adapters and wheel spacers\u003c\/strong\u003e allow future wheel and brake upgrades\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThis is not simply a stiffer fork. It is designed to be stronger where it matters, absorb impacts more effectively, and maintain predictable handling during aggressive riding.\u003c\/p\u003e\n\u003ch2\u003eRace Grade CMX Closed Cartridge Damping\u003c\/h2\u003e\n\u003cp\u003eAt the heart of the F43 CMX is Sirris' CMX tuned symmetrical closed cartridge damping system. This advanced design separates lubrication oil from damping oil, helping maintain consistent performance under heavy use and extended riding sessions.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eCMX Compact Motocross Tune developed for aggressive compact e-moto riding\u003c\/li\u003e\n\u003cli\u003eTrue symmetrical closed cartridge design\u003c\/li\u003e\n\u003cli\u003eIndependent oil circuits for fade resistance\u003c\/li\u003e\n\u003cli\u003eHigh-flow pistons with tunable compression and rebound valving\u003c\/li\u003e\n\u003cli\u003eHydraulic bottom-out protection\u003c\/li\u003e\n\u003cli\u003eHard anodized internal components reduce wear\u003c\/li\u003e\n\u003cli\u003ePremium Daido bushings\u003c\/li\u003e\n\u003cli\u003eNOK MX seals for smooth action and durability\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eWhether riding rough trails, technical terrain, desert sections, or larger jump lines, the F43 CMX remains controlled and highly tunable.\u003c\/p\u003e\n\u003ch2\u003eTool-Free Compression Adjustment\u003c\/h2\u003e\n\u003cp\u003eThe F43 CMX features external tool-free compression adjustment with nearly 30 clicks of adjustment. Riders can quickly adapt suspension settings for changing terrain or riding style without carrying tools.\u003c\/p\u003e\n\u003ch2\u003eDirect Mount Stem System\u003c\/h2\u003e\n\u003cp\u003eThe Sirris steerer tube and motorcycle-style top cap system were designed around direct mount stem setups. This creates a stiffer cockpit feel while helping maintain consistent steering bearing tension similar to larger motocross platforms.\u003c\/p\u003e\n\u003ch2\u003eOptional Drop Clamp for Big Wheel Builds\u003c\/h2\u003e\n\u003cp\u003eThe optional drop clamp raises overall fork height approximately 25mm, extending total fork length to roughly 800mm. This helps riders running larger wheel setups maintain proper geometry and bike balance.\u003c\/p\u003e\n\u003ch2\u003eAxle and Brake Mount System\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eUltra-stiff chromoly axle improves steering precision\u003c\/li\u003e\n\u003cli\u003eReplaceable brake brackets allow future brake upgrades\u003c\/li\u003e\n\u003cli\u003eDesigned for 220mm brake rotor setups\u003c\/li\u003e\n\u003cli\u003eSirris brake brackets designed around 220mm rotors\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eArchitecture:\u003c\/strong\u003e Upside down fork\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTravel:\u003c\/strong\u003e 220mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFree Length:\u003c\/strong\u003e 775mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExtended Length with Drop Clamp:\u003c\/strong\u003e Approximately 800mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFork Spacing:\u003c\/strong\u003e 178mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 4kg per leg\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStanchions:\u003c\/strong\u003e Ø43mm high tensile steel, hard chrome\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOuter Tubes:\u003c\/strong\u003e Seamless 7050 aluminum, Type 3 hard anodized coating\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDrop Outs:\u003c\/strong\u003e 6061 aluminum, Type 2 anodized coating\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAxle:\u003c\/strong\u003e Ultra high tensile hard chromed axle\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTriple Clamps:\u003c\/strong\u003e Billet 6061 aluminum, Type 2 anodized coating, Black or Blue\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSteer Tube:\u003c\/strong\u003e Seamless 7050 aluminum, Type 2 anodized coating\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDamping:\u003c\/strong\u003e Symmetrical adjustable closed cartridge with spring-backed modified IFP\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDamper Bodies:\u003c\/strong\u003e Seamless 7050 aluminum, Type 3 hard anodized coating\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompression Adjustment:\u003c\/strong\u003e External tool-free adjuster\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRebound:\u003c\/strong\u003e Adjustable dual-side high tensile spring system\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSeals:\u003c\/strong\u003e NOK MX seals\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBushings:\u003c\/strong\u003e Daido MX bushings\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFork Guards:\u003c\/strong\u003e High impact PP, 210-degree wraparound\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eSpring Rate Options\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMedium:\u003c\/strong\u003e 140-180 lb rider weight, 3.6 \/ 3.2 springs\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHeavy:\u003c\/strong\u003e 180-220 lb rider weight, 3.6 \/ 3.6 springs\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eRider weight recommendations are based on body weight without riding gear. Sirris factors approximately 15 pounds of riding gear into these recommendations. Additional battery, controller, or accessory upgrades should be added into total rider system weight.\u003c\/p\u003e\n\u003ch2\u003eCMX Tune Setup Notes\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eFactory settings are measured in clicks from fully closed position\u003c\/li\u003e\n\u003cli\u003eFully close adjusters clockwise, then back out counter-clockwise to recommended starting settings\u003c\/li\u003e\n\u003cli\u003eRiders near spring weight cutoffs can fine tune with preload adjustments\u003c\/li\u003e\n\u003cli\u003eAggressive riders may prefer moving up one spring class with reduced preload\u003c\/li\u003e\n\u003cli\u003eTerrain and rider preference may require additional tuning\u003c\/li\u003e\n\u003cli\u003eExample: 160 lb rider with 20 lb of upgrades equals 180 lb total system weight\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eFitment\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eAltis Sigma\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eWho This Fork Is Perfect For\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eAltis Sigma riders building high-performance off-road setups\u003c\/li\u003e\n\u003cli\u003eTrail and desert riders wanting increased front-end stability\u003c\/li\u003e\n\u003cli\u003eJump riders and aggressive riders pushing beyond stock suspension limits\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Sirris Store","offers":[{"title":"220mm - Medium (140-180lbs) \/ CMX - Standard Clamp \/ Black","offer_id":51654041731362,"sku":null,"price":2250.0,"currency_code":"USD","in_stock":false},{"title":"220mm - Medium (140-180lbs) \/ CMX - Standard Clamp \/ Blue","offer_id":51654041764130,"sku":null,"price":2250.0,"currency_code":"USD","in_stock":false},{"title":"220mm - Medium (140-180lbs) \/ CMX - Drop Clamp \/ Black","offer_id":51654041796898,"sku":null,"price":2350.0,"currency_code":"USD","in_stock":false},{"title":"220mm - Medium (140-180lbs) \/ CMX - Drop Clamp \/ Blue","offer_id":51654041829666,"sku":null,"price":2350.0,"currency_code":"USD","in_stock":false},{"title":"220mm - Heavy (180-220 lb) \/ CMX - Standard Clamp \/ Black","offer_id":51654041862434,"sku":null,"price":2250.0,"currency_code":"USD","in_stock":false},{"title":"220mm - Heavy (180-220 lb) \/ CMX - Standard Clamp \/ Blue","offer_id":51654041895202,"sku":null,"price":2250.0,"currency_code":"USD","in_stock":false},{"title":"220mm - Heavy (180-220 lb) \/ CMX - Drop Clamp \/ Black","offer_id":51654041927970,"sku":null,"price":2350.0,"currency_code":"USD","in_stock":false},{"title":"220mm - Heavy (180-220 lb) \/ CMX - Drop Clamp \/ Blue","offer_id":51654041960738,"sku":null,"price":2350.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0093\/1672\/8892\/files\/sirris-F43-220-E-RIde-Pro-suspension-fork-3_4-CMX-black-drop-clamp_4476c89c-e83a-4f3e-8623-fa4cad5a5f43.webp?v=1773352753","url":"https:\/\/revrides.com\/products\/sirris-f43-cmx-tune-220mm-fork-tool-free-lsc-altis-sigma-special-order","provider":"REVRides","version":"1.0","type":"link"}