Kronos RaceSpec Ceramic Shimano Bottom Bracket Bearings – 2 bearings
Specifications
| Return Shipping Will Be Paid By | Buyer |
| All Returns Accepted | Returns Accepted |
| Item Must Be Returned Within | 30 Days |
| Refund Will Be Given As | Money Back |
| Material | Ceramic |
| For Component | Bottom Bracket |
| Part Type | Bearings |
| MPN | Does Not Apply |
| Compatible Bike Type | Road Bike - Racing |
| Brand | Kronos |
Kronos RaceSpec Hybrid Ceramic Bearings sized 6805-7 (25mm I.D. X 37mm O.D. X 7mm width) with 2 rubber (2RS) low-drag seals Fits: Shimano Dura Ace 7800, 7900 Shimano Ultegra 6700, 6600, 6601 Shimano 105 5600 Shimano XT, XTR (Hollowtech I, II) Shimano Other: Hollowtech I, II Up for auction is a quantity of two (2) brand-new fully race-tested Kronos RaceSpec hybrid ceramic bearings. The inner and outer races are specially heat treated oil-quenched extremely high-strength AISI 52100 alloy steel with superior hardness in the Rockwell C range of 62 to 64 making it perfect for bicycle racing and touring applications. The races are then precision ground to ABEC 5 specifications. The Silicon Nitride (Si3N4) ceramic balls are the finest commercially available in a Grade 3 roundness. Two low-drag rubber seals help to keep out the grit and water to further prolong the life of the bearing. A high-quality PEEK retainer is used to separate the ceramic balls for trouble free operation. And finally, the bearing is filled with Kyodo Yushi PS2 grease for low viscous drag and great lubrication. Kronos' engineers have worked with many bearing companies over the years to come up with bearings that are specifically designed for bicycle applications. We've worked with SKF, Fag, and many other US, European, and Asian manufacturers to arrive at an optimum designed bearing for use in the relatively low speed applications usually involved with bicycles. This 6805-7 bearing is the result of our collaboration with these companies. This sized bearing is commonly used in Shimano Hollowgram bottom brackets as well as many other uses. We've tested our bearings to last as much as 3 times longer than the typical steel bearings with a reduction in drag. This is a great upgrade to reduce bearing drag on your bicycles. 1. Inner and Outer Race Material: AISI 52100 Steel Rc ~ 62 super hard alloy steel high strength for great durability 2. Si3N4 ceramic balls with a Grade 3 sphericity (the most precise grade) with a density of 3.2 grams/cm3 (steel is 8.0 gr/cm3). 3. Races are precision ground to ABEC 5 standards which is extremely precise 4. Extremely high quality PEEK retainer 5. Kyodo Yushi PS2 multi-temp low viscosity grease 6. Two low-drag rubber seals to minimize seal drag. 7. Weight: 19.5 grams each (39 grams for pair) Original MGF Retail Price: $39.95 (each bearing) Shipping and Handling in U.S. is $2.75 for first item and free for each additional item. Shipping and Handling for Europe, Asia, and South America is charged at my cost by the United States Postal System for international packages. I don't add any handling charges.