Apologies if this is a dumb question!:

I am teaching myself some bike maintenance skills and was removing my crank and BB. However, the ParkTools videos I've been following show BOTH ends of the BB cartridge having a cup to remove.

When I tried the same on mine, I could remove the non-chainring side, and then remove the entire cartridge through the chainring side. I don't know if the cup should be removable, or do some have them built in.

This is all the info I can find on the cartridge and I couldn't find any writing on the cartridge itself:
Bottom Bracket - VP square taper, 73mm shell, english thread

  • 2
    The square-tapered ones I know are exactly as you describe: Removable cup on the non-drive side, nothing removable on the drive side.
    – linac
    Commented Sep 5, 2016 at 13:55
  • You also need the axle size (something like 113-122.5 mm likely). Also, when selecting the replacement, I'd opt for something with metal cups not a plastic one.
    – Batman
    Commented Sep 5, 2016 at 15:38
  • 1
    It depends on the cartridge. The Shimano cartridge that was originally in my current bike had a "fixed cup" on the drive side, but my replacement Phil Wood cartridge had removable cups on both sides. The removable cups allow the same cartridge to be used with different threading schemes, and also allow the cartridge to be aligned left-right to a degree. Commented Sep 5, 2016 at 17:05

1 Answer 1


Most of the standard square taper bottom brackets on the market (e.g. Shimano BB-UN54/BB-UN55) have one cup permanently attached to the bottom bracket (usually drive side) and the other one removable.

However, some manufacturers make ones with both sides removable (e.g. Phil Wood) and some other variations on installation (notably threadless ones like the Velo Orange Grand Cru Universal).

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.