SHIMANO BB-5500 BSA bottom bracket 118

Shimano BB-5500 bottom bracket with Octalink mount is dedicated to road bikes. It comes from group 105 where low weight is a priority. The Octalink technology, thanks to the axle with a large tube cross-section, provides much greater stiffness than traditional square bottom brackets, thus ensuring better energy transfer to propel the bicycle.

Specification:

• Octalink crank axle
• Adapted to support joints with a width of 68 mm
• Axle length: 118 mm
• Standard BSA (English) thread - BC 1.37 "x24T
• Works with M15 crank mounting bolts
• The kit does not include the bolts securing the crank arms to the bottom bracket shell

Technologies used:

• OCTALINK Bottom Bracket Attachment - Comparing the OCTALINK power transmission to conventional square lugs, the OCTALINK 8-Spline which connects the bottom bracket and crank increases the stiffness of the overall structure. This is all thanks to the use of a hollow axle and a more effective connection of the crank arms with the bottom bracket axle. It is the successor of the square crank mounting system. Its shape, i.e. a round shaft with eight protrusions (this is where the name of the system comes from: octa or eight), can withstand and dissipate the forces that this place is subjected to better, in addition, this connection is much stiffer than the previous solution.