Building your dream headset may not be a goal on every cyclist's list, but we heartily support the endeavor, and so does Cane Creek. Its 110 Series IS52/40 Bottom represents one of several separately-sold headset pieces that let you choose exactly what will work with your frame and budget, and as its 110 Series, it's the best of the best from a company who only manufactures high-end componentry. Part of Cane Creek's integrated headset line, the IS52/40 comes compatible with a bottom head tube inner diameter of 52. 1mm. Its dual-seal aluminum crown race measures 39. 79mm in diameter and it adds a 1mm to the bottom stack height. Fittingly, Cane Creek includes sealed stainless steel bearings ready to block out grit and water to give you a creak-free ride from now until the next century. Yes, we're serious -- the 110 Series comes complete with a 110-year warranty, so with the proper maintenance, (and barring any significant scientific advancements), your headset could very well outlive you.