The ceramicspeed shrouded OSPW has been spotted at various bike events around this week. This video covers some of the technical aspects around the product - mainly the aerodynamics.
Overall, it's very expensive for a product that probably saves very little. It exists and some people will no doubt buy it. At a guess I'd say it was worse than an OEM shimano cage, owing to the fact it uses ceramic bearings and massive pulleys - the mechanical losses and the size of shroud in an attempt to reduce the Cd are negated.
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