Zipp Ceramic Bearing Upgrade Kit 61903 for ZR1 / ZM2 / Cognition Disc Hubs

This upgrade kit for Zipp wheel hubs includes two type 61903 ceramic bearings, which are compatible with ZR1, Cognition Disc and also with older hubs. Ceramic balls made of silicon nitride, bearing races made of chrome-molybdenum-nickel steel, polyamide cages as well as non-contact seals ensure improved function, longer durability and lower friction.

Specifications:

Dimensions (Inner x Outer x Width):

17 mm x 30 mm x 7 mm

Designation:

61903 (6903)

Technical Information:

Design:

deep groove ball bearings

Recommended Use:

hubs

Inner Race Material:

stainless steel (chrome-molybdenum-nickel)

Outer Race Material:

stainless steel (chrome-molybdenum-nickel)

Ball Material:

Ceramic (Si3N4)

Compatibility:

• ZR1 front and rear hubs
• ZR1 Disc front and rear hubs
• ZM2 front and rear hubs
• Cognition V1 Gen 2 rear hubs
• Cognition Disc V1 front and rear hubs
• Cognition Disc V2 front and rear hubs
• 76 Disc front hubs
• 176 rear hub
• 176 Disc rear hubs
• 77 Disc front hubs
• 177 rear hub
• 177 Disc rear hubs

Features:

• ideal upgrade for Zipp wheels or hubs, reduces friction and breakaway torque
• silicon nitride ceramic ball bearings for higher durability
• corrosion-resistant bearing races made of a hardened stainless steel super-alloy on a chrome-molybdenum-nickel basis
• polyamide ball bearing cages for vibration damping and insulation, improved function and durability
• contact-free seals possible thanks to high strength
• manufactured in Germany by a medical device specialist

Note from the manufacturer:

To upgrade a whole wheelset you need three kits (six bearings): two kits (4 pieces) with 61903 bearings for the front and rear hub shells and one kit (two bearings) with 61803 bearings for freehub bodies. Alternatively, you can fit two sets of bearings 61903 in the hub bodies to get the most benefits.

Manufacturer Number:

11.2018.067.000

Contents:

Zipp Upgrade Kit, consisting of:

• 2 x 61903 ceramic bearings (17 mm x 30 mm x 7 mm)