3

I've a threaded shell, but i have got bb30 cranks, can you get threaded bb30 bottom brackets that the it can with fit the bb30 cranks?

  • I've a threaded shell Does that mean your frame itself has an Italian or BSA/English threaded bottom bracket shell? And you want to use a BB30 crankset on it? – Andrew Henle Dec 14 '18 at 16:17
  • I've a english thread. Yes, i want to use a bb30 crankset. – Ervins K Dec 14 '18 at 16:20
4

There are some solutions in forms of bottom brackets designed to run 30 mm cranks in a threaded BSA bottom bracket shell. The deciding factor is the spindle length.

Searching the net for "bb30 crankset in bsa frame" gives e.g. this:

Threaded to 30mm Angular Contact BB - Black

Our solution for running a 30mm spindle crankset in a BSA threaded frame.

Notes:

For use with 30mm diameter cranks with a spindle length of at least 104mm. Will not work with standard BB30 cranksets.

  • This is 100% correct, the limitation is the spindle length. I run 30mm THM Clavicula SE cranks on a THM BB on a BSA frame. I was also going to run FSA Cranks BB386EVO Cranks on a FSA MegaEvo Road BB that also work. – sjakubowski Dec 14 '18 at 20:48
1

can you get threaded bb30 bottom brackets that the it can with fit the bb30 cranks?

That won't work, as the threaded bottom bracket shell simply isn't large enough.

BB30 cranksets have a 30mm spindle diameter. Per Wikipedia, the maximum internal width of an English or Italian-threaded bottom bracket is about 34 mm. Those few millimeters are not enough space for bearings.

I also think the BB30 crankset spindle will be too short.

  • But bearings can be in external cups and as such won't be limited to 4 mm – Grigory Rechistov Dec 14 '18 at 18:38
  • Yep, BB30 spindles are designed for BB shells either 68 or 73mm wide, so you can’t have an external bearing solution. – Argenti Apparatus Dec 14 '18 at 19:25
  • The bottom bracket is more than large enough. The issue is only the spindle / offset on the crank. – sjakubowski Dec 14 '18 at 20:49
  • @sjakubowski The bottom bracket is more than large enough. Seriously? What kind of bearing fits in the 2mm or so between the 30mm spindle and the 34 mm bottom bracket shell? Unless the OP already has a crankset designed for BB30 and outboard bearings, there's nowhere to put the bearings. It "won't work". – Andrew Henle Dec 14 '18 at 21:10
  • I didn't say it would work, I said the reason you mentioned is incorrect. I gave examples of 30mm diameter cranks working just fine on BSA. If you replaced the spindle on a BB30 crank with a longer one it would work just fine. – sjakubowski Dec 14 '18 at 21:15

Your Answer

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.

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