"PRESS-IN" BOTTOM BRACKET FOR MOUNTAIN BIKES

BB91, BB92, BB89.5

KCNC® 6061 ALUMINUM PRESS-IN ASSEMBLY 
WITH ENDURO®
ANGULAR CONTACT CHROMIUM STEEL BEARINGS
 
 
 
$58.00 Complete BB
(Two-Piece Aluminum Design)
 
 


PRESS-IN BB MTB, SHIMANO VERSION (HT2)

ABEC 5 ANGULAR CONTACT* CHROMIUM STEEL $58.00

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FOR SHIMANO HOLLOWTECH 2 CRANKSETS
*BOTH BEARINGS ANGULAR CONTACT FOR 1OO% BALL ENGAGEMENT AND LONGER BEARING LIFE


PRESS-IN BB MTB, SRAM VERSION (GXP)

ABEC 5 ANGULAR CONTACT* CHROMIUM STEEL $58.00

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FOR SRAM GXP CRANKSETS
*BOTH BEARINGS ARE ANGULAR CONTACT FOR 100% BALL ENGAGEMENT WHEN USED WITH INCLUDED WAVE WASHER. 


Angular contact bearings result in 100% ball engagement when pre-loaded.  Chromium steel bearing races are given Cryogenic Treatment after heat treating.  The ball bearings are Grade 10 steel with nylon retainers.  The cartridges are ABEC 5 level precision.  The sealed bearings are packed with an 80% fill of Almagard Extra High Pressure grease.  For future service, the bearings are easy to disassemble.

This press-in bottom bracket is designed for use on frames with a BB shell inside diameter of 41mm.  A 2.5mm cup spacer is included for use on frames with BB shells that are 89.5mm wide. BB shells that are 92mm wide do not require the spacer. Because manufacturing tolerances vary, on many frames no special tools will be necessary to install the cups as they will press in by hand.  On frames with a tighter fit, a mechanical means of pressing in the cups may be required.  This can either be a dedicated tool for BB86/BB92 applications, or you may improvise with a threaded rod, nuts, and fender washers. A center seal where the two-halves meet provides sealing from the inside of the frame.

Angular contact bearings are a step forward in outboard bottom bracket design.  Why? Deep groove radial ball bearing cartridges are not designed to be "adjusted."  Any inward or outward pressure on the inner races put them out of alignment with the outer races, forcing the balls to ride up the side of the groove and exerting greater pressure on the races.  This results in increased friction and premature wear.  Since almost all outboad crank sets exert some inward pressure on the bearings when installed, it only makes sense to use a bearing designed specifically for such loads. 

 
These Bottom Brackets do not use axle shims,
allowing us to reduce the bearing ID and use
larger balls for greater strength!