10 Best Square Taper Bottom Bracket of December 2025

• Square taper interface
• Sealed no service bearings
• Plastic left cup
• Shimano Reference Number: BB-UN26

SHIMANO

• Fits JIS square-taper cranksets
• Crankarm fixing bolts sold separately
• Bottom Bracket Shell I.D.: 1.37
• Spindle Length: 107
• BB Shell Width (mm): 68 mm

SHIMANO

• 113mm spindle length
• Heat treated CrMo JIS square-taper spindle with M8 (crank mount) thread bore and CNC machined alloy cups/spacer-shell
• 325g

Truvativ

• A good quality bottom bracket for traditional chain sets
• Super-accurate bearings for smooth operation and improved durability
• Durable, hard-wearing sealed cartridge bottom bracket with square tapered spindle fitting
• Lightweight hollow spindle
• Fast and easy installation without adjustment

SHIMANO

• Smooth ceramic ball bearing axis, greatly improving abrasion resistance and not easy to rust.
• Dear buyer, due to lighting effect, monitors brightness, manual measurement, etc., there could be some slight differences in the color and size between the photo and the actual item. Sincerely hope that you can understand! Thank you!
• Made of high grade material, durable in use.
• Its lubricity makes it easier for you to compete in bicycle racing, more effortless.
• Applicable: folding bicycle, dead fly, highway, mountain bike, etc., as long as the width of the five-way is 68MM, and it is threaded, it can be used.

BESPORTBLE

• Forged alloy body and cups
• CNC hollow chromoly spindle
• Sealed cartridge bearings
• SHIMANO Equivalent BB-UN55

Origin8

• Fits JIS square-taper cranksets
• Spindle Length: 113
• BB Shell Width (mm): 68 mm
• Bottom Bracket Shell I.D.: 1.37
• Crankarm fixing bolts sold separately

SHIMANO

• WANT THE LIGHTEST or CERAMIC MODEL? See the full TITANIUM & CERAMIC version at link at bottom.
• CRANKSET FIT: SHIMANO and other JIS 2.0° Degree Square Taper type
• SUPER SMOOTH PREMIUM BEARINGS: Premium ABEC 5 standard, Grade 5 Chromium Steel Balls, and polished 52100 High Carbon Chromium alloy races sealed with X-SEALS. Extremely close tolerances for I.D. and O.D., roundness of ball, trueness of the races and micro surface finishes of balls and races.
• SUPER LOW FRICTION X-SEALS: Patented technology uses Low Friction Dual Lip Seals housed in the Premium bearings and CNC machined alloy cups. This allows the seals to fit very precisely and allow for less contact between the rotating parts in order to reduce energy-wasting friction. In addition, the seals provide better protection for the bearings since there is less space for the elements to get past the seals.
• LIGHTWEIGHT SHAFT: Strong and stiff CNC machined hollow CROMOLY STEEL shaft for extra weight savings. JIS 2.0 degree square taper shaft.

OMNI Racer

• Fits JIS square-taper cranksets
• Crankarm fixing bolts sold separately
• Hollow spindle
• 50mm chainline

SHIMANO

• Fits JIS square-taper cranksets
• Crankarm fixing bolts sold separately
• Hollow spindle
• Spindle Length: 110
• BB Shell Width (mm): 68 mm

SHIMANO