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External BSA Bottom Brackets


SKU: xtrnlbsabttmbrckts
Clear Options


White Industries external BSA style bottom brackets are made here in our shop with U.S. sourced 6061-T6 aluminum and feature Enduro stainless steel anglular contact bearings or Enduro XD-15 ceramic radial bearings where available.  We offer them with three different bearing sizes to help you fit your favorite crank to your favorite bike.

“BSA” bottom bracket shells and cups are named after the Birmingham Small Arms Company which created the thread standard used in this system.  It’s also referred to as “British” or “English” style and is the most common type of system found on modern bicycles.  The “external” designation refers to the fact that the bearings will sit outboard of your frame’s bottom bracket shell as opposed to being tucked inside the shell as you would find on some styles of BSA bottom brackets.  


  • Comes in three bearing sizes to fit:
    • 30mm White Industries M/A/R/G cranks as well as other brands of 30mm spindle cranks
    • 29mm SRAM DUB cranks
    • 24mm Shimano HollowTech II cranks
  • Dust seals included with all models
    • Seals should sit directly against the bearings, with the part numbers (molded into the seal) facing out
  • Internal BB sleeves are not available for our BSA bottom brackets


  • 1.37” x 24 TPI threads (“BSA” threads)
  • Designed to be used on 68mm or 73mm wide bottom bracket shells
  • Weight/pr (with bearings and seals)
    • 30mm: 83g
    • 29mm: 90g
    • 24mm: 84g

Cup Dimensions, Spacers and Bearing Info

  • White Industries cranks
    • No spacers needed with R30 and G30 cranks on 68mm shells (73mm shells are too wide)
    • No spacers needed with M30 and A30 cranks on 73mm shells
      • On 68mm shells, use one 2.5mm BSA cup spacer on each side

See the chart below for the “OBW” (Outer Bearing Width) of each bottom bracket and compare that to the allowed OBW for your crank (ask the crank manufacturer for this, not us!).  Most cranks these days have an adjustable bearing preload collar on them that can accommodate slightly wider/narrower OBW’s than their target number, but again, you’ll need to check with your particular crank’s manufacturer. When in doubt, start with few spacers than you think you need so you don’t crush and destroy your bearings!

  • If the allowed OBW of your crank is less than the OBW of our bottom bracket, our bottom bracket will not work (it’s too wide for the crank)
  • If the allowed OBW of your crank is more than the OBW of our bottom bracket, our bottom bracket will work but you may need spacers

How many spacers?

  • Other brands of 30mm cranks
    • Compare the allowed OBW of the crank to our bottom bracket OBW
  • 29mm SRAM DUB cranks
    • Using SRAM’s charts, look at the BSA row, find your shell width, find your crank model, then see what spacers they require
    • SRAM DUB road crank spacer chart
    • SRAM DUB mountain crank spacer chart
    • Our cups w/seals add 2mm in overall width (1mm for each cup/side) compared to SRAM DUB BB cups, so subtract 1mm from each side of SRAM’s spacer numbers
    • If SRAM calls for no (zero) outer/spindle spacers on the non-drive side (left), you may have to subtract 2mm from the drive side (right) to make things fit
    • Ex: SRAM calls for 3mm of spacer on the right and zero on the left, run 1mm on the right and zero on the left.
  • 24mm Shimano HollowTech II cranks
    • Our cups are the same width (each) as Shimano road BB cups
    • Our cups are 1mm wider (each) than Shimano mountain BB cups but are compatible with Shimano mountain cranks




Spindle Diameter Fits Cranks Cup Width (w/seals) OBW

(Outside Bearing Width)


on 68mm/73mm BB Shells

Enduro Stainless Steel Bearing

Enduro XD-15 Ceramic Bearing





30mm White Industries Etc. 11.5mm 91mm/96mm 6806 6806 6806XD



29mm SRAM DUB 12mm 92mm/97mm 6806/29 6806/29 6806/29XD



24mm Shimano HollowTech II Etc. 11.5mm 91mm/96mm 2437 2437 2437XD




White Industries

Bottom Bracket Model

Description Cup Notches/Diameter



BSA threads, external cups, 30mm spindles 12 notch/46mm

Abbey BSA30

Park BBT-79

Enduro BBT-015

Race Face Cinch spanner


BSA threads, external cups, 29mm spindles 12 notch/46mm

Abbey BSA30

Park BBT-79

Race Face Cinch spanner


BSA threads, external cups, 24mm spindles 16 notch/44mm

Park BBT-9

Park BBT-19.2

Park BBT-69.2

Abbey Tools BB Common

Enduro BBT-015

Enduro TorqTite spanner

Shimano TL-FC33


  • 26-37 ft lbs (35-50 Nm)

Techical Documents


Additional information

Weight N/A
Dimensions N/A
BB Spindle Diameter

24mm, 29mm, 30mm


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Bearing Type