Bottom bracket for 24 mm cranks, for road cranks FC-R3000, FC4700.

Progressive performance in all directions. That's what the 10-speed SHIMANO TIAGRA set represents, offering a versatile collection with technologies adapted from the DURA-ACE set.

• Seal construction for long-lasting performance.
• For a frame width of 70 mm

HOLLOWTECH II

• Providing the best balance of stiffness, strength, weight and rotating performance.
• The concept of HOLLOWTECH II technology is focused on producing a superior crankset which will maximize a rider’s power transfer. The rigidity of the crankset ensures pedaling efficiency while its weight, a key element of the crankset, you want light, aids in cycling longer distances over which the rider needs to pedal more.
• Naturally, SHIMANO strove for the optimum balance between the conflicting needs of stiffness while producing a lightweight crank. HOLLOWTECH technology is an ultra-lightweight hollow crankarm created by SHIMANO with the company’s own proprietary forging technology that also maintains rigidity.
• The HOLLOWTECH II crankset has been developed by pursuing the optimum balance of stiffness and rotating performance in a lightweight and beautiful crankset design.
• Moreover, HOLLOWTECH II crankset has a high-precision sealing in the bearing area to increase durability maintaining the excellent rotating performance for long periods.