Put the rims on a flat surface like a granite counter top or glass-topped table and check them for warpage. Inspect the joint for defects like steps, bulges or constrictions. An out-of-round condition is unfortunately difficult to detect by measurement; a rim can be quite out-of-round and have a constant diametric measurement, like these shapes: Shapes of constant width ? set of 4 ? Maths Gear Check the drilled holes for defects; out-of-round, burrs, etc. Shake the rims if double-walled and listen for things rattling inside (these will drive your customers nuts.) Examine the brake tracks for defects.