104BCD 42T Single Speed Wide Chain Narrow Round Mountain Bike Features: 104BCD Discs: For M370, M410, M610, M670, M780, Jiankun IXF, FRO part of Hao Meng discs, etc. One-piece high-speed CNC tools to ensure strength and beauty, do not fade, beautiful atmosphere. The modification of the transmission is more constant, no need to change the forward and reverse gears at the same time to achieve a continuous transmission ratio. Features: Name: narrow and wide ring . Material: 7075 aluminum alloy. Color: black. Specifications: 42T. Weight: about 115g . Outer diameter: approx. 177 mm. Disc type: round disc. BCD: 104 mm. Usable crank : 104 mm BCD Compatible with 8/9/10/11/12 speed chains from major brands. Reminder The BCD is 104 mm, so if you buy the crank, make sure your crank is 104BCD (the diameter of the circle created by the center of the four pins is 104mm, not wrong, or you can't be wrong or not install it. Note: 1. The actual color of the item may vary from the color of the pictures depending on your computer's display and brightness settings. Thank you. 2. Due to hand measurement, sizes shown may vary by 1-2cm. Contents: 1 Narrow Round Tray. 104BCD Discs: for M370, M410, M610, M670, M780, Jiankun IXF, FRO part of Discs, etc. One-piece high-speed CNC tool machine, to ensure solidity and beauty, never fade step, beautiful atmosphere The gear ratio change is more constant, no need to change the forward and reverse gears at the same time to achieve a continuous gear ratio