GOLDIX | GOLDIX R9100 HG Ultralight Road Cassette 11S 12S 11-28T~11-36T 128g CNC Hollow Freewheel K7 Sprocket HG Hub Racing Gravel Bike

Product SpecificationsBrand: GOLDIXModel: R9100Product Type: Road Bike Cassette (HG Standard)Speed Options: 11-speed / 12-speedFreehub Compatibility: Standard Road HGMaterial Construction: High-wear-resistant steel + 7005 aluminum alloyFinish/Color: Iridescent steel cogs + Black aluminum alloy large cogsCompatible Bikes: Drop-bar road bikes, rim-brake road bikes, disc-brake road bikes, gravel bikes, touring road bikesKey Selling Points1. Steel-Aluminum Hybrid Design: Balancing Lightweight Performance and DurabilityThe GOLDIX R9100 utilizes a composite structure combining steel and aluminum, with materials allocated based on the specific stress characteristics of each cog.Black Large Cogs: 7005 High-Strength Aluminum AlloyThese large cogs are CNC-machined from a single piece with a hollowed-out design; by retaining critical structural ribs while removing excess material, the design reduces cassette weight and rear-wheel rotational inertia, making starts, acceleration, and climbing feel effortless.Iridescent Small Cogs: High-Wear-Resistant SteelSmall cogs endure frequent use and concentrated chain engagement pressure. Consequently, they are crafted from high-wear-resistant steel and feature an iridescent finish, enhancing durability, resistance to deformation, and visual distinctiveness.Steel handles high-frequency engagement, while aluminum alloy provides lightweight structural support.II. Optimized tooth profile for smooth shifting transitionsThe sprockets feature ramp profiles and progressive tooth shapes optimized for multi-speed road drivetrains. This design facilitates smooth chain movement between adjacent sprockets, minimizing noticeable jolts during upshifts and downshifts.Suitable for daily cruising, continuous gear changes, shifting while climbing, and high-speed riding.Actual shifting performance may be affected by the following factors: shifter and rear derailleur models; chain speed compatibility and wear level; rear derailleur hanger alignment; tension and limit screw adjustments; shift cable tension; chain length; and cassette/drivetrain compatibility.Freehub and drivetrain compatibility notes11-speed version: Compatible with standard road HG freehubs that meet length and structural requirements; requires matching 11-speed road shifters, rear derailleurs, and chains. Shorter 8/9/10-speed HG freehubs generally cannot accommodate 11-speed road cassettes directly;please verify the freehub length before purchase.12-speed version: Compatible with standard road HG freehubs meeting installation requirements; requires matching 12-speed shifters, rear derailleurs, and chains. The need for a spacer should be determined based on the specific freehub structure, cassette width, and the locking status after installation.Do not ride if the cassette wobbles or the lockring cannot be tightened securely.Important Note:A 36T sprocket falls outside the official compatibility range of the common rear derailleurs mentioned above. Forced installation may result in: insufficient chain length, abnormal rear derailleur tension, the guide pulley rubbing against the largest cog, chain drops or inaccurate shifting/noise when using the small chainring with the largest cassette cog, or abnormal rear derailleur operating angles. It is recommended to pair this with a rear derailleur system explicitly designed to support 36T and to re-verify chain length and tension.This product is a lightweight road bike cassette intended for proper installation, correct adjustment, and standard road cycling use.Cassettes are drivetrain wear items; the following issues are not considered product defects (placing an order constitutes acceptance of these terms):Skipping gears or noise caused by using an old chain; guide pulley rubbing due to insufficient rear derailleur capacity; incorrect chain length; bent derailleur hanger or incorrect shifting adjustment; lockring not tightened to specifications; cog damage caused by forced shifting under high load;Installation on an incompatible freehub body or for the wrong number of speeds; normal wear marks on the iridescent finish caused by chain friction.Not compatible with: XD, XDR, MS, or short-style MTB HG freehub bodies. Please verify the freehub type, drivetrain speed, rear derailleur capacity, and chain length before purchasing.The 11-speed and 12-speed versions are distinct products; please select the correct speed version based on your shifter, rear derailleur, chain, and overall drivetrain system—they are not interchangeable.