Aluminum Alloy: The chainring is forged from aluminum alloy, providing strength and impact resistance with uniform force distribution for smooth riding. Anodized Process: The surface is treated with anodization to effectively protect the aluminum alloy body and prevent rust and oxidation. Main Features: High-precision positive and negative positioning grooves ensure strong engagement. The arc entry angle with alternating wide and narrow tooth design reduces chain wear, decreases load, prevents chain drop during riding, and ensures efficient power transmission. Mud Discharge Oblique Mouth: The unique sludge discharge design prevents silt buildup, allowing smooth gear operation. Application: This direct mount narrow-wide chainring is compatible with SRAM GXP cranks and 8-11 speed chains, suitable for direct mount and DUB cranks, and designed for use with 148mm bike frames. Item Type: 40T Direct Mount Narrow Wide Chainring for GXP Specification: 40T Material: Aluminum Alloy Product Diameter: Approx. 170mm / 6.7in Offset: 3mm / 0.1in Product Weight: Approx. 127g / 4.5oz Process: One-piece turning and milling, anodized finish Compatibility: Compatible with GXP Crank and 8/9/10/11 Speed Chain Description for GXP Direct Mount Chainring Offset: 1. SRAM mountain bike cranks use a standardized three-bolt interface, and the mounting pattern is universal across crank types. This means the same mounting interface applies to GXP, BB30, PF30, and DUB cranks, regardless of crank specification. 2. Direct Mount Chainrings for SRAM are available in 0mm, 3mm, and 6mm offset options. Offset selection is not determined by frame type alone. A larger offset brings the chainring closer to the frame. The purpose of offset is to optimize chain line alignment, which depends on the bottom bracket and crankset used. 3. Frame design limits the maximum chainring size. Larger chainrings may not fit due to clearance constraints. For example, if a 6mm offset ring causes interference, a 3mm offset may be used instead, keeping the chain line farther from the frame. 4. Chainrings with 0mm offset are generally less expensive and easier to manufacture. When chain line alignment is not a concern, 0mm offset rings offer a cost-effective option. 5. When selecting an offset, note that using a low-offset chainring with mismatched cassette sizes may increase chain angle when shifting to extreme gears. While chain drop is unlikely due to the narrow-wide design, excessive chain angle can accelerate wear and increase noise. 1 x Narrow Wide Chainring