Replacing my bb30 bearings and spotted cracks in the housing. Any comments on what to do? Is this housing replacable? Carbon frame.

Looks like wall art.

Not sure I unerstand.. You think this is only superficial? Hope you're right..
You did notice that the crack goes all the way to the bolt hole inside, and also on the outside?

"Wall art" in this context means the frame is dead, i.e. it's only value is to hang on the wall and look at it.

I don't know if that assessment is correct, just explaining the terminology.

Okay, thanks for clarifying.

..and its seeing things like these that makes me hold off on buying anything with these new pressfit style bottom brackets. maybe in a few more years when the bugs are all sorted out

There are carbon fiber frame repair shops that can replace the cracked sleeve. One of the most respected (and expensive) is https://calfeedesign.com/repair/ . Get an estimate from them for comparison and search some other repair shops. I don't know enough about any other shops to recommend one but you may be able to find reviews to determine if you want to go with someone other than Calfee. Out of curiosity what is the brand, year and model of your frame?

If that crack is really into the carbon shell then the options are to have an expert like Calfee repair it or replace the frame. The picture shows what seems to be a metal insert that is cracked and that would have to be replaced which will also require expert repair since it is certainly bonded in.

BTW, some manufacturer's have a lifetime warranty for the original owner for their frames. If you are the original purchaser and have your sales receipt, contact the manufacturer about a warrantee replacement or major discount on a new frame.

To all: Thanks for help and tips.

The frame is a Bianchi Sempre (2011). I think Bianchi had a 5 year warranty on frames (so 1 year late).

I have checked with a carbon repair shop, and it will cost too much (550 usd for fixing the carbon if i replace the alloy insert.

I have sent pictures to Bianchi as well to see what they can do.

Many brands will extend "unwritten" warranty coverage to original purchasers. Also crash replacement discounts are often offered. If I were the shop this was sold through and if I still sold Bianchi I would pressure Bianchi to offer something.


But as already mentioned carbon is not always a lifetime frame. Until the buying public votes with their pocket books brands will still push the limits of minimal weight and sometimes their customers will suffer the results before they think they should. Andy.

Well, in this case it was the aluminum insert that were broken, not the carbon.. The shop i bought from has stopped selling Bianchi, so I first try to contact Bianchi directly to see what they say..

No ...contact the dealer, don't skip them .. they can still help you (or be given a chance to try).

Service calls flow backwards from distribution. bring your sales invoice.

Yep, I will - and I have contacted them - they wanted to get the bike to see if the could press out the insert. I very much doubt that they can, and I "need" the bike almost every day so I just check out other options first.

Option: adapter to use a threaded BB, epoxied in, it will bridge the crack with a new layer of aluminum..
But that will void any possibility of having it your frame pictured, replaced.

If you need a bike to commute on, N+1, & get a steel frame. not carbon..

For the reliability factor .... you have discovered its shortfalls...



...

The problem here is that if the metal ring is meant to distribute force to the CF frame, and its cracked, you may end up doing irreparable damage to the CF by riding it. If its a press in/press out collar it may be a quick fix for them.

Back in the days of steel frames, the best I ever got was two seasons. Just about all the manufacturers, cracked on the down tube where the cables connect. Then I changed to a carbon Colnago C40. I believe that was 18 years ago, it is still going strong after more races and crashes I would like to remember. I believe today it is just a matter of being careful about the BB standard you choose when buying a carbon frame. Some still get it right, most don't.

This is what would do. I would apply epoxy to the crack. Install new bearings and keep riding it.

I still have the bike I built the frame, DIY, in 1975.. a Touring type.


racing?.. yes the whole bike is a consumable.

Pros may go thru several a season, that is why pro teams bring a truck full of spares..

I have 3 aluminum bikes and a carbon TT-bike too, so the commuting will do just fine
But I am in the last weeks before my A-races this season and need my road racer with power meter..

While this might work, or doing nothing to the frame and riding it may work, using epoxy (alone) to repair CF or metal is gonna be pretty useless. The tensile strength of CF is in the carbon fiber, not in the epoxy matrix. CF is way (20-100 times) stronger than epoxy. Same for metal. So to repair a joint in CF or metal that already was too weak to survive, with a far weaker adhesive is probably futile.

Really, the only solution is to have your frame repaired properly, by machining out the current aluminum insert and molding a new insert in place. You can perhaps press the bearing in with Loctite 638 and hope for the best, provided the carbon housing around the insert is solid with no cracks. If it were me though, it would bother me while racing more than the $550, or new frame cost out of my pocket.

What BB was in there?

If you use a BB with an adapter that presses into the BB30, using Loctite 638, you will have a much better chance of success.

Its a bb30. But with an insert i would have to buy new crankset (including stages pm).. so i guess that solution also will lose to getting new frame.