This press-in bottom bracket is specifically designed for original aluminum Pivot Cycles. These frames have protrusions inside the BB shells that prevent the use of normal BB sleeves. In addition, the press fits were unusually tight, sometimes over-compressing the bearings. Our BB cups are machined to the perfect tolerance to fit the Pivot BB shells. The bearing-to-cup clearance has also been custom engineered to prevent ovalized BB shell tubes from distorting the bearings--leading to much longer bearing life than the OE bottom brackets provide. The machined aluminum center sleeve is a special narrow design that won't interfere with the extruded supports that protrude inside the Pivot aluminum BB shells.

ENDURO ANGULAR CONTACT CERAMIC HYBRID "CH SERIES" GRADE 5 BALLS / ABEC 5 CARTRIDGE RATING

THE BALLS are made from pure Silicon Nitride material with extreme high density from uniform compaction (3.25 g/cm3). The micro-structural development of this material during manufacture is second to none. These high precision Grade 5, SI3N4 pure ceramic balls are 5/1,000,000” from exactly round in sphericity. They are 60% lighter in weight, and 7 times harder than steel. Friction is reduced to near zero.

THE RACES ARE A PATENT-PENDING ANGULAR CONTACT DESIGN with vacuum de-gassed alloy hardened to Rockwell C-64. These high precision races are cryogenically treated not once, but three times during the final "super polishing" phase. Cryogenic treatment means taking the races down to minus 300º Fahrenheit to nomalize the crystalline structure of the material so that the races will resist the hardness of the ceramic balls and get the maximum wear potential. This critical treatment to the races is left out by many manufacturers, but not by Enduro.

THE RETAINERS are nylon with Graphite and are virtually frictionless.

THE SEALS are "LLB" low contact labyrinth type, with 2 sealing lips which fit into a matching groove on the inner race. The outer sealing lip repels dirt and water while the inner sealing lip retains the grease. When the bearing is first turned, you will notice some grease will come out of the sea