Zipp Upgrade Ceramic Bearing Kit - 61903
ZIPP Ceramic Bearing Upgrade Kit (2 ceramic bearings included) - 61903 - compatible with ZR1/ZM2 hubs, Cognition rear, Cognition/76 front for disc brakes, 176 all rear hubs
Two 61903 bearings for the hub shell, front or rear.
The Zipp hub ceramic bearing upgrade kit uses the highest quality materials and precise machining for maximum speed. The bearings are manufactured in Germany by a medical device specialist to Zipp's exact specifications. The bearing kits are manufactured and assembled in one location to achieve precise tolerances. The bearing races are made of hardened aluminum superalloy with the addition of a chrome-molybdenum-nickel compound, which is the highest grade of stainless steel available. Zipp testing has shown this material to be corrosion resistant, even in saltwater.
Zipp's designed combination of material and ceramic balls (Si3N4) results in significant bearing durability. The high durability and long life of the bearings allow for the use of non-contact seals on the ceramic bearings. The result is a bearing kit that significantly reduces friction and breakaway torque for the hub shell and cassette driver (freehub body). The cages inside the bearings are made of polyamide instead of steel. Polyamide has vibration-damping properties to isolate the balls, leading to improved performance and lifespan. The Zipp ceramic bearing upgrade kit is the ideal upgrade for Zipp wheels and hubs.
To upgrade a complete wheelset, 3 bearing kits (6 bearings) are required: two kits (4 bearings) of 61903 bearings for the front and rear hub shells, and one kit (2 bearings) of 61803 bearings for the freehub body. Alternatively, you can install just the two kits of 61903 bearings for the hub shells and gain most of the benefits.
COMPATIBILITY
Zipp ceramic bearing kits are compatible with all current Zipp hub models, both rim and disc brake versions: Cognition, ZR1, ZM2, 76/176, and the previous generation 77/177. These kits are not compatible with the first generation Cognition rim brake hubs.
| product ID | 174172 |
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