Specifications is_customized:Yes Model Number:1350 Sensitivity:108 Sounds Flywheel Adjustable Gear Number:13S Material:STEEL Gear Teeth:11-50T Freewheel Speed:13 Origin:Mainland China Components:Freewheel MTB Bike 13 Speed 11-50T Cassette FIT FOR HG SYSTEM Color: Black-silver MATERIAL: Sprockets :Steel Spider :Aluminium WEIGHT : About 595g RATIOS: 11-13-15-17-19-21-23-25-28-32-36-42-50T Compatible with 11 speed ROAD HG hub. Yeah! MTB 13speed is coming! The Earlier Thoughts. Talking about lose cassette's weight, the first thing we came up with somthing like this. A CNC machined spider and some steel cogs riveting on it. This is might be a cheaper solution, but larger cogs would still be quiet heavy. The weight could go up to 415 grams, even that is better than orginal 660 grams, but we are not satisfied. The Idea Of CNC Larger Cogs. After studing a lot of famous brands, we are start to looking into a one-piece full CNC solution. Full steel design is the best solution for the strength and durability, but full steel cost a lot. Then we consider the full aluminum design, but use aluminum alloy to make smaller cogs could make cassette easy to wear out. So we decide to only use aluminum alloy to make larger cogs. Smoother Gear Ratio We use11-13-15-18-21-24-28-32-36-40-46-52Tgear ratio,With a smoother gear ratio, it will be easier for rear derailleurs to shift. Full CNC Machined 7075 Aluminum Lockring Not only beautiful anodized color,these lockrings could be extra lightweight and strong. REAR DERAILLEUR HANGER EXTENSION ALSO COULD IMPROVE THE SHIFTING PERFORMANCE OF LARGER CASSETTES