vundo 170mm bike crankset mtb bicycle single speed 1x 3x crank arm set for mountain road hollow tech aluminum 104bcd black without bottom bracket vundo <b>specification:</b><br><b>material:</b>aviation aluminum,3d forged process;<br><b>surface:</b>high quality surface anodizing; <br><b>crank length:</b> 170mm;<br><b>diamter of alxe:</b>24mm; <br><b>chain ring bcd:</b>104mm;<br><b>bb of frame:</b> bc1.37*24t-68/73mm screw bb or press bb92 ;<br><b>compatible with:</b><br> 1.1x,2x,3x speed chainring;<br> 2.shimano,sram(need 24mm to 22mm conversion kit),fsa, gaint atx770 atx770-d xtc 750;<br><b>weight:</b><br>one pair crank arm:682g;<br>bottom bracket:100g;<br>