CeramicSpeed Oversized Ceramic Pulley Wheel System - SRAM Red eTAP

CeramicSpeed’s mission is to get mechanical friction down to zero. They’ve done bearings for every component on your bike. Now, they’ve applied their thinking to derailleur pulleys. That’s where the Oversized Pulley Wheel System for SRAM comes in. OSPW is the acronym. This is for both SRAM’s eTap and Red rear derailleurs.

Jockey wheels have gotten bigger over the years. By one tooth in most cases. Bearings have gotten better. CS has pressed their bearings into pulleys built by others. But that wasn’t good enough for them. Rather than accept the industry dictating the size of derailleur pulleys, they decided to determine which size would be ideal. They determined that seventeen-tooth pulleys would not only dramatically reduce friction, but keep shifting performance crisp. Because such pulleys are too big to fit in conventional pulley cages, they also had to design the cage system, which is made of carbon reinforced polyamide. Even with the oversized aluminum pulleys, larger bearings, and oversized cage, the total weight for the system is only marginally higher than the stock cage and pulleys. And even with the increases size of pulleys and the custom cage (carbon-fiber, of course), the rear derailleur, which is designed to accommodate 11-28 cassettes

In terms of aerodynamics, there is no aero penalty. In some cases, at some yaw angles and rim depths, there is actually an aero gain.

More importantly, there’s the watts savings. It’s at lest 40% over what SRAM’s own ceramic-bearing pulleys. The larger pulleys spin at 65% of the speed of smaller pulleys, which further helps increase durability of the system-CS bearings already last three to five times longer than standard SRAM pulleys. And when the day comes that you realize you’ve worn out these pulleys, CS has replacements at the ready.

The heart of the system are CeramicSpeed’s standard hybrid ceramic bearing. CeramicSpeed utilizes Grade 3 Silicon Nitride balls that possess the best possible surface finish and roundness. In testing, the balls are 400% smoother, 128% harder, and 58% lighter than standard steel balls found in most bike components. They’re more than 100% smoother and 15% harder than standard ceramic balls. The balls are installed into hardened steel races in dust-free clean rooms and then checked again before assembly is complete.

As you can imagine, installing this system is a bit more involved than replacing pulleys. Rest-assured, it is more straightforward than it looks. You’ll need a Philips head screwdriver and a set of Allen keys. You can perform the installation on the bike or off, though on makes the installation a bit easier. You’ll probably also need a few more links in your chain, so starting with a new chain might be the easiest way to begin. Check out the linked videos to see how its done.

Additional tip: when packing the bike for plane travel, remove the rear derailleur from your bike. This is always a good idea, but for the OSPW it goes double. The larger pulley size means the pulleys stick out behind and under the frame more.

The kit comes with the pulleys assembled on the cage, an instruction manual, sticker sheet, and oil for lubing the bearings.

In addition to there being different Red and eTap versions, there are also coated and uncoated pulleys. Coated have less frictional resistance and last longer, but the weight is the same.

The CeramicSpeed Oversized Pulley Wheel System for SRAM eTap and Red never stops rolling.