Shimano BB-ES300 Octalink bottom bracket

This is the basic (and currently the only) Shimano bottom bracket model with an Octalink interface, designed for MTB and trekking bikes. It is used in groups , , , as well as in older crankset models from higher-level groups.

Thanks to its large-diameter tubular axle, Octalink technology provides considerably greater stiffness than traditional square-taper bottom brackets, thereby ensuring more efficient energy transfer to the bicycle drivetrain.

The BB-ES300 was introduced as a replacement for its predecessor, the BB-ES25. It differs from that model by having approximately 10% lower weight.

Specifications:

- axle for cranks using the Octalink standard

- suitable for bottom bracket shells with a width of: 68 mm

- axle length: 118 mm

- standard BSA (English) thread – BC 1,37" x 24T

- compatible with M15 crank fixing bolts

- average weight: 270 g

Important! The set does not include bolts for fixing the crank arms to the bottom bracket axle. If required, they are available separately from us.

Shimano technologies used:

OCTALINK bottom bracket interface – Compared with power transfer using conventional square tapers, the 8-spline OCTALINK interface, which connects the bottom bracket axle and the crankset, increases the stiffness of the entire construction. This is achieved through the use of a hollow axle and a more efficient connection between the crank arms and the bottom bracket axle. The bicycle crank mounting system was developed and patented by Shimano. It is the successor to the square-taper crank mounting system. Its shape – a round shaft with eight splines (hence the system name: octa means eight) – withstands and disperses the forces acting on this area more effectively. In addition, this connection is considerably stiffer than the previous solution.