Shimano 105 BB-5500 Octalink Bottom Bracket

he 105 BB-5500 bottom bracket from Shimano is an Octalink bottom bracket with 8-speed gearing and a steel axle. The 109.5 mm versions are compatible with 2-way cranks, the 118.5 mm versions with 3-way cranks. Even though it has been around for a while, this bottom bracket still holds up.

Specifications:

Application: Road
Series: 105 5500
Type: BSA, ITA
Shell Width: 68 mm, 70 mm
Axle Length: 109.5 mm, 118.5 mm
Axle Type: Octalink (Road)
E-Type Compatibility: no
Chaincase Compatibility: no

Technical Information:

Bearings: steel
Axle Material: steel
Bottom Bracket Cup Material: Aluminium

Compatibility:

– Octalink crank arms with eight-speed splines for shorter grooves (Octalink MTB)

Features:

– 8x toothing of bottom bracket axle and crank

Technology:

Octalink
In Shimano’s Octalink system, the bottom bracket and crank are connected by an 8-tooth contact surface. This provides greater rigidity and greater load capacity, especially compared to conventional square systems.

Models:

BSA 68×109.5:
Threads: BSA
Shell Width: 68 mm
Axle Length: 109.5 mm
Compatibility: 2-speed
Manufacturer Number: E-BB5500B09

BSA 68×118.5:
Threads: BSA
Shell Width: 68 mm
Axle Length: 118.5 mm
Compatibility: 3x
Manufacturer Number: E-BB5500B18

ITA 70×118.5:
Threads: ITA
Shell Width: 70 mm
Axle Length: 118.5 mm
Compatibility: 3x
Manufacturer Number: E-BB5500I18