I would warn off anyone looking at the Zipp 900. I feel the hub design is pretty weak and the bearings in there are not up to the job, just too small for the loads they see. I only use my disc a handful of times each year but the bearings go notchy on a regular basis, and are very fussy to get installed correctly. Shops have done it wrong twice for me. If buying new again I would go FFWD if looking for the same price point and am currently in the market for a used Mavic/Campy/Araya disc to replace this one.