Bottom Brackets

- One-piece bottom bracket cup set - Bearings included - Fits smaller american juvenile/youth sized BB - Shell: 65mm - Cup Material: Steel - Weight: 173 grams

Shimano's BB-UN55 Square Spindle Bottom Brackets are the unofficial standard for English-threaded cartridge bottom brackets. Quality, value, and durability come together to keep you cranking for many, many miles. - Fits JIS Square-Taper Cranksets - Hollow spindle - Crankarm fixing bolts not included

- Left and right bottom bracket cups with standard bearings for FSA MegaExo cranks - BB-9050 is for 24mm spindle 68/73mm MTB K-Force and Team Issue cranks - BB-8681 for K-Force Light (a non-ceramic option) and SLK Light Road MegaExo cranks (BB-8681 bearing covers have been redesigned so that the spindle now rides directly on the bearing itself) - BB-7000 is for 24mm spindle 68/73mm shell MTB Gravity Lite, Moto X and Afterburner cranks - BB-7000 is for 24mm spindle 83mm shell MTB Gravity Lite cranks - BB-6200 is for 24mm spindle 68mm shell Energy, Gossamer and Omega No Bolt Design cranks - BB-6000 is for 24mm spindle 68mm shell Energy, Gossamer and Omega cranks - BB-4000 is for 19mm spindle 69mm shell Omega cranks - BB-1000 is for 19mm spindle 68/73mm MTB Gamma cranks - 1.37" x 24tpi (English threads) or M36 x 24tpi (Italian threads)

- Fits 3-piece crank set - Includes right and left cup, lockring and bearings - English type - Shell: 68/73mm - Cup Material: Steel - Weight: 123 grams

- With plastic washers - Shell: 8mm Allen head axle bolt

Dimension American bottom bracket for one-piece cranks. - Include cups, bearings and cones - 24 tpi