10/11/12 speed mtb road bicycle heel separate ultralight aluminum alloy cassette bike wheel bracket sprocket

[speed]10 11 12 speed compatible with shlmano, sram(sram xd incompatible) [color] nickel chromium silver (specially treated surface) [material] high tension steel plate, aluminum alloy bracket, [characteristics] high tension steel plate nickel chromium plating processing, hollow design, reduce weight, high cost, high wear-resistant steel imports, multilayer electroplating antirust, design, high precision gear transmission smooth, strong compatibility, professional climbing heel.