OSBB bottom bracket (2014 Specialized Roubaix SL4 Sora) swap for Dura Ace 7700 cranks
#1
Newbie
Thread Starter
Join Date: Aug 2020
Posts: 2
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
OSBB bottom bracket (2014 Specialized Roubaix SL4 Sora) swap for Dura Ace 7700 cranks
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.
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.
#2
Senior Member
Join Date: Feb 2018
Posts: 1,410
Bikes: 2017 Specialized Allez Sprint Comp
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 850 Post(s)
Liked 344 Times
in
247 Posts
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.
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.
Last edited by smashndash; 08-10-20 at 02:32 PM.
#3
Newbie
Thread Starter
Join Date: Aug 2020
Posts: 2
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
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