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Question Need help with my bottom bracket

Oct 21, 2020
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I have Boardman Team Carbon road bike with FSA Crankset, and I want to make an upgrade, so I bought a full SHIMANO 105 R7000 groupset.

Now I have a problem with the bottom bracket size, so I have to buy an adapter to fit the new 24 mm crankset with the bottom bracket or an entire bottom bracket.
Now I’m confused, I see two different numbers, the one on the bearing say “BB30” and the one on the bottom bracket say “B3155”, so correct me if I’m wrong, if I’m gonna buy an adapter then I’ll get the one which compatible with BB30, but if I’m gonna buy an entire bottom bracket then I’ll choose B3155 / PF30?
 
If it's a BB30 then you can either:

  • Buy shims to reduce the current BB to fit the Shimano crank spindle .
  • Buy a converter that will allow you to run the Shimano crank.
Personally, I'd buy the converter. BB30s can be a noisy and because the bearings sit in the frame and because of the tight tolerances required, things that don't fit just right can cause problems. Adding shims is just another area where you can introduce errors. Praxis, Wheels Manufacturing and Rotor make a converter.
 
Oct 21, 2020
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Ok, now I’m making sure that either these options are right:
I have found this converter on Amazon:


or if I’m gonna replace the entire bottom bracket I can buy this one:


I’m just making sure that I’m right
 

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