so i work in a shop. during assembly we adjust the hubs, 1 piece cranks, headsets etc. they want me to set the preload of the bearings pretty high, i can feel notchyness at the end of the handle bars for headsets. for solid axles they want notchy feeling axles when spun by hand. surprisingly qr wheels are adjusted properly with slight play in the axle when not clamped. i learned that bearings should have only enough preload to get rid of any play. they say that the high preload is so that customers wont experience loose headsets and hubs. i thought the 'free' tune up that every bike gets is to cure these break in issues. so what are you thoughts? high preload bearings to keep the customers happy or cost cutting so customers dont return and clog up the service dept?