Octane one 2pcs crankset pro the lightest strongest coolest octane one tubular chromoly crankset comes in a popular trendy two piece format 170mm crank arms made of high quality seamless 4130 chromoly tubing with full heat treatment the 19mm diameter hollow axle with 48 micro splines eliminates the need of pinch bolts making this crank arm lighter and gives it a clean look 48 splines provide a large area of contact eliminate the stress points this makes the connection more reliable an