Black cylindrical device labeled "Rotation Engineering," with grooved ends. Appears mechanical or industrial, conveying precision and durability.
A metallic, cylindrical bike component with the text "Rotation Engineering" printed on the black central section. Silver threaded ends feature ridge details.
A metallic, cylindrical bike component with the text "Rotation Engineering" printed on the black central section. Silver threaded ends feature ridge details.
A metallic, cylindrical bike component with the text "Rotation Engineering" printed on the black central section. Silver threaded ends feature ridge details.
A metallic, cylindrical bike component with the text "Rotation Engineering" printed on the black central section. Silver threaded ends feature ridge details.
Close-up of a black cylindrical mechanical part, labeled "Rotation Engineering." It has threaded ends, a smooth surface, and exudes a sleek, industrial look.
Close-up of a black cylindrical mechanical part, labeled "Rotation Engineering." It has threaded ends, a smooth surface, and exudes a sleek, industrial look.
Close-up of a black cylindrical mechanical part, labeled "Rotation Engineering." It has threaded ends, a smooth surface, and exudes a sleek, industrial look.
Brown and black cylindrical device labeled "Rotation Engineering," with grooved ends. Appears mechanical or industrial, conveying precision and durability.
Brown and black cylindrical device labeled "Rotation Engineering," with grooved ends. Appears mechanical or industrial, conveying precision and durability.
Brown and black cylindrical device labeled "Rotation Engineering," with grooved ends. Appears mechanical or industrial, conveying precision and durability.
Brown and black cylindrical device labeled "Rotation Engineering," with grooved ends. Appears mechanical or industrial, conveying precision and durability.
A bicycle bottom bracket with purple threaded cups and a black center bearing labeled "Rotation Engineering." The design appears sleek and modern.
A bicycle bottom bracket with purple threaded cups and a black center bearing labeled "Rotation Engineering." The design appears sleek and modern.
A bicycle bottom bracket with purple threaded cups and a black center bearing labeled "Rotation Engineering." The design appears sleek and modern.
A bicycle bottom bracket with purple threaded cups and a black center bearing labeled "Rotation Engineering." The design appears sleek and modern.
Rotation Engineering

BSA Threaded Bottom Bracket

Sale price$349.00
Bearing Type: Ultimate - Ceramic
Spindle Diameter: 29mm
Color | Width: Bronze | 68-73mm

Description

Rotation Engineering’s new BSA is our most evolved model. Of course, we use premium 7075 Aluminum & Titanium (Ti-6AL-4V). Accurate thread geometry and the precise bearing bore press fit tolerance were maintained to ensure consistent installation and performance. We modified the back of the cup with a small standoff so that it would align better with the frame after chasing and facing. Your bike shop can now face the frame with the smallest 44mm or 45mm BB face cutters instead of using the much larger 57mm cutter that was previously recommended. The gap geometry between the outer flange of the cup and the reducer flange  create a tight-fitting, zero contact labyrinth seal. A hydrophobic Nano-particle paste is added to the inside of the bearing reducer flanges and outer bearing seal to gain more protection against water ingress and contamination.  A square cut seal has been added to the outside of the reducer where it meets the crank arm and spindle to seal this critical area. We still offer two pre-assembled bearing options STANDARD and ULTIMATE (description below).  For frame and crank fitment we support three crank spindle diameters (29mm-24mm/30mm) and two frame width options (68mm-73mm). Crank spindle spacers are not included.

  • The STANDARD bearing option features hardened 52100 high chromium races, PEEK Cage, and steel ball bearings, two low friction rubber seals and a specially formulated anti-corrosion low friction bearing grease and our NanoGliss Race Coating. This option is for the more budget-oriented customer that still wants a premium USA-made bottom bracket.

  • The ULTIMATE bearing option features one low friction rubber seal facing out, one non contact PEEK shield on the inside, a PEEK bearing cage, a specially formulated ceramic-bearing-optimized, low-friction grease, grade 3 silicon nitride balls,  hardened 52100 high chromium bearing races that have been isotropicly polished and coated with our NanoGliss Race Coating for the ultimate blend of durability and performance. This option is for the consumer that wants the ULTIMATE, period!

 

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