An upgrade option for cartridge wheel bearings that offer extremely low friction, improved power transfer, and a service life that far exceeds traditional steel bearings.
*Grade 3 Silicon Nitride balls
*Hardened races
*Reinforced polyamide cage and non-contact seals
*Hand built in Denmark
*High resistance to poor lubrication
*6 x 61803 bearings
*Fits Zipp wheels with 188/88 hubsets