CeramicSpeed ??Ceramic Oversized Pulley Wheel Black for Shimano Dura Ace 9100 and Ultegra 8000

CeramicSpeed ??makes some of the strongest, most accurate and lightest rolling bearings on the market, they are all ceramic.

Ceramic bearings also provide a better utilization of one's wattage.

Oversized Pulley wheels are, as the hub suggests, pulley wheels that are larger than normal, this gives less movement in the chain, which therefore gives less energy loss and ultimately a greater power transfer.

Only fits Shimano Dura Ace 9100 and Ultegra 8000.

Comes with a new rear derailleur arm so you can change the whole set that way.

Made of aluminum and with ceramic bearings.

607 tenants.

With a 13 tooth pulley wheel at the top and a 19 tooth pulley wheel at the bottom.