jwible204

Hello - I picked up an old 7700 full groupset for $175 a few months back. I'm naive and assumed it would be an easy swap, turns out that is true for all but the crankset. I've spent a bunch of time researching and from what I can gather my bike has an OSBB bottom bracket (or BB30, I'm seeing conflicting information online).

I don't quite follow the path to use the 7700 crankset. I think there's bottom brackets I can buy to adapt but I'm struggling to fully understand if that's true or which one would work.

Here's a pic of my current frame where the bottom bracket is. I can't attach the pic either.

This site indicates that due to the year, it's OSBB, but it also says if there's any aluminum visible than it's a BB30. I can't post the link as I'm too new here.

smashndash

So do you see any aluminum? You can also pretty easily measure the BB shell.

Specialized Carbon OSBB was 61mm wide with a 46mm hole. BB30 or alloy OSBB is 68mm wide with a 42mm hole.

That being said, it seems that Dura Ace 7700 cranks use octalink. Trying to fit an octalink BB in a pressfit shell is a rabbit hole I wouldn’t recommend diving into. Look for a 9 speed Hollowtech II crankset like Sora R3000 and just get an OSBB or BB30 to HT II adapter like:

https://wheelsmfg.com/pressfit-30-to...ano-black.html

or

https://wheelsmfg.com/bb30-to-outboa...ano-black.html

depending on what you have.

jwible204

Ok this is excellent. There is aluminum showing, yes. But according to the bluebook website it's OSBB, but that conflicts with another writeup I saw that said if aluminum is showing then it's BB30. I'll measure tonight and see