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BB30a to Shimano

  • 30-01-2023 11:11am
    Registered Users Posts: 6,823 ✭✭✭

    Hi folks

    Having terrible trouble the last while with my CAAD 12. I can't afford to buy a new bike right now so I need to fix this.

    I have replaced the BB bearing twice since August (August, December, and need to do again now)

    Last bearings got only 900km. I was 100% sure they went in straight. Everything done right. But the BB has always given hassle (for as long as I can remember)

    I came across this thread after a BB30a 'search' Hambini vs Cervelo — - Now Ye're Talkin'

    What adapter options do you recommend I use? I will have to buy Shimano cranks and they'l be over €100 so I need to keep the cost of an adapter down (at least for now)

    I don't want to spend €120 on this if possible BB30A Outboard ABEC-3 BB for 24mm Cranks (Shimano) - Black (

    I have a threaded Ultegra BB to use with an adapter

    Can I please have some recommendations for a cost effective solution to this BB issue



  • Registered Users Posts: 8,189 ✭✭✭07Lapierre

    What trouble/hassle are you having with your existing BB?

  • Registered Users Posts: 6,823 ✭✭✭G1032

    Replaced both bearings in August. Shot by December and not huge mileage done. Replaced both in December and they're shot again. Play in the cranks. The original bearings lasted about 10k km but since then I can 't get get bearings to last p!ssing time. I've got LBS to install. I've installed myself. can't keep horsing bearings into the bike every 1k or so km.

  • Registered Users Posts: 6,823 ✭✭✭G1032

    I can see loads of BB30 to 24mm but not so many BB30a adapters. Was hoping someone here had previous experience of this and or cost effective recommendations

  • Registered Users Posts: 1,644 ✭✭✭Large bottle small glass

    Try @Seweryn.

    He's got 130k km on his caad 10, I know he figured outvbb bearings.

    If he's not on boards anymore I'll drop him a text for you

  • Registered Users Posts: 14,175 ✭✭✭✭ednwireland

    Replace bearings, replace wavey washer, tourqe the crankbolt correctly. If you overtighten you put to much pressure on the inner race and the bearings just wear out

    That's what I understood from reading round how bb30 setup works.

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  • Registered Users Posts: 6,823 ✭✭✭G1032

    I wouldn't rule this out. I will replace the worn bearing tonight and get a torque wrench to

    Thanks! He's on boards. I'll message him now.

  • Registered Users Posts: 6,823 ✭✭✭G1032

  • Registered Users Posts: 2,953 ✭✭✭Plastik

    For reference, Caad10 is BB30 and runs the cables external around the BB. Caad12 is BB30a and runs them internally, so some of the options to convert to "BSA" for the 10 won't work on the 12. I've the FSA threaded sleeve pressed into the shell on my Caad10 - won't work on the 12.

  • Registered Users Posts: 6,823 ✭✭✭G1032

    Drive side bearing was the culprit. Tiny bit of roughness (if I'd even call it that). One thing for sure is that it's not water ingress causing the wear. No dirt in there. The grease still looked perfect after 900km. Put it all back together with a new drive side bearing. Will torque it tomorrow when I get a torque wrench. So could be that I'm over tightening when replacing them (although it didn't take any big effort to undo the locknut). Or it could be the shell compressing the bearings. What a sh!tshow though. Threaded brackets are just the business.

  • Registered Users Posts: 4,406 ✭✭✭Gerry

    Ive a caadx, I didnt actually have problems with the bb30 but pre emptive change to threaded, as the standard omega crankset was rubbish.

    Used FSA adapter, solid bit of kit. Threaded shimano bsa bb and ultegra crankset. zero problems since.

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  • Registered Users Posts: 648 ✭✭✭Whatwicklow

    I am using these adapters for a bb30a caad12 with ultegra crank, no issues.

    *BB is c5000km old and just started creaking.

  • Registered Users Posts: 6,823 ✭✭✭G1032

    These use the existing bearings though? I want to get rid if them 😂. I stuck with the FSA chainrings. Hindsight is 20:20 but I should have just converted this a long time ago. The 52/36 never suited me anyway. 36T just too small.

  • Registered Users Posts: 6,823 ✭✭✭G1032

    Agreed. Total and utter rubbish. The CAAD12 has a BB30a which makes adapting it that bit more awkward (or should I say options for adapters more limited)

  • Registered Users Posts: 2,953 ✭✭✭Plastik

    I don't particularly like those cup adapters that you slot in either, they just give one more possible interface for creaking to occur. FWIW, I converted my Caad10 because I bought it frame/fork and the only chainset I had to hand to put on was a Campag one. I've a Caad12 and SuperSix Evo here and they're both still running as true BB30 setups.

  • Registered Users Posts: 4,487 ✭✭✭Seweryn

    Thanks :-). And yeah, my CAAD is still going.

    I have responded to @G1032 directly, however, after looking at this thread I see there may be a different issue here.

    First of all - the play in the cranks. Assuming the bearings are new and installed correctly, the play in the crank axle occurs when the bearing seizes tight and causes the wear on the bearing contact point on the aluminium crank spindle. I assume that is not the case here, but it would need to be looked at. The other situation when you may have a play in the cranks is when the crank spindle is not positioned in its "sweet spot" left-right. In some cranks the bearing contact surface(s) may be slightly missaligned; and you may be able to get that sorted by adding an extra shim on one side of the crank (if there is a space for it) to compensate for that.

    So, there may be an issue with the crank / installation. A close inspection would be ideal, but if you have detail photos of the installed bearings in the BB shell and the crank spindle contact points to see if there are any damages, it may be helpful.

    Another thing comes to mind - when installing the bearings in the BB shell, I would recommend to always use the retaining compound (medium strength). It is a liquid that helps the bearing to settle in the sleave and fixes it in its position. It helps to prevent the damage to the frame in case the bearing would seize.

  • Registered Users Posts: 420 ✭✭CtrlAltDelete

    I am using these on my Synapse HiMod with a BB30a shell. Regular BB30 bearings. Silky smooth and zero creaking.

  • Registered Users Posts: 6,823 ✭✭✭G1032

    Interesting... Re the spindle. After installing the new drive side bearing last night I found it very difficult to get the spindle back in. It's like it didn't want to go in straight through the new bearing (for want of a better phrase). Ended up just giving it a good whack and it went through and both bearings. I wouldn't rule out a tiny misalignment there but if it was misaligned would it go all the way through the non drive side bearing smoothly? I don't know if I've any of that explained very well at all. 🙈

  • Registered Users Posts: 881 ✭✭✭nicksnikita

    The fact that the original bearings lasted 10k km suggests that alignment is fine and that the issue is installation/bearing quality related.

    What’s the difference between BB30 and BB30a?

    If the frame can take one of those fsa sleeves or a Token-style thread-together bb, I’d be tossing a coin between them and going down that route

  • Registered Users Posts: 6,823 ✭✭✭G1032

    The 'a' stands for asymmetrical.

    It's a wider shell and supposedly stiffer. I doubt that 99.99999% of all people would ever notice a difference. Just more of the usual marketing bùllsh!t we're constantly bombarded with.

    BB30a shell is 73mm wide v standard 68mm

  • Registered Users Posts: 881 ✭✭✭nicksnikita

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  • Registered Users Posts: 4,406 ✭✭✭Gerry

    used a press kit I'd normally use for car suspension bushes. very straightforward really. I realise bb30a a little trickier but in case anyone reading this thread has a bb30

  • Registered Users Posts: 648 ✭✭✭Whatwicklow

    I have an older specialized stumpjumper too that I converted from pf30 to shimano, I bonded in A FSA alloy sleeve that takes a threaded bb, it works well and would be a solution

  • Registered Users Posts: 881 ✭✭✭nicksnikita

    I’ve used this solution for BB30 conversion in the past also but it won’t work for the BB30a (as far as I can see).

    The op will need to opt for something like the one he has linked in above from Wheels mfg. ie One to suit BB30a specifically