The bottom bracket has gone on my 2011 Specialized Stumpy Evo.

The old bearing assembly needed hammer and drift to remove from the frame. Bought a new Sram PF30 from Chain Reaction and it looks exactly the same BUT it just slides into the frame and on measuring the original and new bearing there is a 2/3 thou size difference in the cap sizes.

The old bearing would still go in tight with the right tool, but the new one just drops in.

Local bike shop got another one from the UK distributor and exactly the same problem. Too small!

Anybody else come across this problem? Specialized aren’t offering much help. I’m not happy fitting a bearing that is slack in the frame.

Interested in this. I have the same bike and these bottom brackets do seem to be very unreliable, so interested in the outcome for when mine goes.

Awesome bike though…

Are you sure your new BB is Pressfit30? Could it be BB30? I think that has a slightly smaller O/D.

Can’t realy mix them up, BB30 bearings press directly into frame, pressfit 30 come in nylon cups. Definatly don’t put them in loose that will cause wear to the frame and compound the problem however i can’t beleive specialized aren’t any help they should know whats fitted.

http://www.cycleservicenordic.com/f/f1/Bottom-brackets-English-version.pdf

Its a BB30 press fit, bottom right hand corner. Had a headset bearing remover and a headset bearing press to fit it in.

Yes, the new and old are both definitely press fit. The image below matches exactly what I purchased from chain reaction and the one that came from the bike shop where I purchased the bike.

They both look exactly the same as what originally came on the bike, apart from the tiny difference in size! Bike shop is trying to get some info from Sram tomorrow.

Both the new bearings I have tried can be pushed in by hand, and slide in and out easily 😕

Cammer that’s the same that came out of mine, replaced like for like. Mine took a bit of ‘persuasion’ to come out, slid in easy like John Holmes.

The normal FSR is bb91-42a. Is that the same as bb30? I didn’t think it is…

Any update yet, Cammer?

Awaiting a response from Specialized who are talking to their people in America. The frame might be going in for warranty.

Checked with a couple of local shops and none have not seen the problem before. I have compared 3 new BB’s with the original, and all have been a different size.

So no, I haven’t had an answer yet but i’ll report back.

I changed my 2011 evo bb twice last year with no problem. But sold the frame before Xmas could sram have a duff batch

Any news?

Hi Rickos, Specialized just told me to use the new BB as it was, (ie just push it in by hand).

I’ve had the bike out for a couple of rides and whilst it has been ok, there is a slight bit of movement starting to appear if you move the cranks with your hands.

My LBS have made a note of the communication with Specialized so if the play gets worse or the BB doesn’t last very long i’ll be straight back to them.

Still doesn’t seem right to me, but can only see how it goes for now. I still think Specialized have messed up somewhere as it doesn’t get away from the fact that the measurements on original and new BB’s are different!

Do you think that specialized fitted an oversize one originally due to a tolerance issue and got a special batch from SRAM slightly over sized?

Thanks Cammer. Seems a bizarre response, so I’ll be interested to see what mine’s like when it needs changing.

Exactly what I was thinking Mr Plow. I mentioned that at another local well known bike shop and got shot down immediatly saying they wouldn’t be allowed to do that. Well I think that is exactly what they have done!

I don’t think we have seen the end of this problem, the new BB won’t last long with the movement, it’s easily going to wear much faster then it should 👿

Not that I want your BB to fail any time soon Rickos but I’ll be interested to see how you get on

The normal FSR is bb91-42a. Is that the same as bb30? I didn’t think it is…

+1

This one I think

BB91-42

This is the BB spec from the Specialized website for the 2011 Stumpy EVO –

SRAM PF-30, OS press-in bearing, sealed cartridge

Your link is for Shimano, not for the oversized 30mm crank spindle on the EVO model.

I think…

New BB non-standards are ridicluous.

Wonder if it sells more frames, can’t save more than 50g or something, most people I know are actively avoiding them when possible now.

Makes frames cheaper to produce.Like a lot of so-called ‘advances’.

I don’t know what to think but am watching this as a friend has an Evo frame to build up later in the year. It is very odd that the “same” parts are a different size in the frame and that Spec told you to put the smaller one in given your reportings to them.

They are a big old company so if they had a big bad batch they may have been able to get SRAM to help them out. I remember reports that Spec had over sized 05-06 Enduro headtubes and that some people were having issues putting chris king headsets in for this reason. There was even discussion about slightly oversize headsets.

A strange situation here if the parts are the right ones.

It is very odd that the “same” parts are a different size in the frame and that Spec told you to put the smaller one in given your reportings to them.

We even sent a video to Specialized showing how it fit. Their response as above ‘that’s how they go in, and to run it like that’

So much for working to a standard size. Interesting about the previous headset problems. Waiting to see if this topic comes up more as others replace their bb’s. I guess some will just throw the replacement in and not notice the difference.