Trek Madone CF-BB liner/shell replacement?

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bikes4two
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Re: Trek Madone CF-BB liner/shell replacement?

Post by bikes4two »

Dave W wrote:" In late 1997/early 1998 they phased in a new, much improved bottom bracket shell. The original shell wasn't bad, but because the internal aluminum sleeve ended flush with the carbon fiber surrounding it, it was possible to put a compressive load on the carbon when installing a bottom bracket, which, in some cases, caused a disbond between the aluminum shell and the surrounding carbon. This didn't happen often, but we did see some frames that had to go back for replacement (under warranty) of the bottom bracket shell.


The frame in question is circa 2007 but the BB construction is similar to as you describe above in that the internal aluminium sleeve is close to being the same width as the CF surrounding (albeit the sleeve did seem to protrude maybe 1mm beyond the CF surrounding). The ease with which I removed the sleeve certainly suggests a disbonding.

I visited my local Trek dealer today - over the phone they were optimistic of a fix having resolved similar problems (BB sleeves coming loose) in the past, but on seeing the frame they do not feel that there is enough surface area inside the BB surrounding to adequately secure (a locally made) new sleeve. Further, they were of the view that this problem had been developing for some while - given that I've only had the bike for about 6 weeks, one wonders if the seller knew of this problem? And in correspondence with others, it does seem that using a ST (square taper) BB puts the most stress on the BB sleeve bonding (as Brucey said up thread).

I am coming around to the fact that this frame is beyond repair, at least in a meaningful way!

One option I'm considering is to manufacture something that would in essence be a one-shot job, e.g. permanently bond some H-II bearings in a sleeve and bond the sleeve into place with as much bonding material as I can get into the space available. Obviously once the BB bearings are worn, then that's the end of the frame.

What 'industrial strength' adhesives are to be had I wonder?
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cycleruk
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Re: Trek Madone CF-BB liner/shell replacement?

Post by cycleruk »

Check out the video on this website:-
http://praxiscycles.com/pages/conversion

Don't know if it will help but may give you an idea for a repair.
You'll never know if you don't try it.
Brucey
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Re: Trek Madone CF-BB liner/shell replacement?

Post by Brucey »

I think it is quite likely that the problem had been developing for at least as long as the ST BB unit had been installed. The vendor may well have known or suspected that there was a fault. Did you ask the Trek dealer about the adhesives and sealants you found? It could be that the sealant wasn't OEM but a bodged repair.

If you fit a new threaded sleeve there is no reason to glue the new BB cups into the sleeve; there is no point in doing that at all.

Unlike your LBS I'd be optimistic about bonding a new sleeve in to the frame. A good adhesively bonded joint, loaded in shear, has a static strength of ~ 1 tonne per square inch. What I'd not be so optimistic about is that the CF around the BB shell isn't at all damaged.

If you want to give the new sleeve the best anchor possible, there may be a way of giving it more support.

What I have in mind is that there could be four short internally threaded bungs fitted, one to each of the chainstays, the down tube and the seat tube. Each of the bungs would be attached to the sleeve by a countersunk bolt from the inside of the sleeve. The bonding operation would be done in two stages; first, the bungs would be bonded into position, using the sleeve as a jig. Next the sleeve would be bonded into the BB shell, and the bolts fitted to each of the bungs using loctite.

Using this approach you should be able to roughly double the surface area of the joint between the new sleeve assy and the BB shell vs how it was before. In all cases the bonded joint will have optimum strength if there is a film of adhesive of ~0.5mm thickness in all the joints, so a 1mm clearance on the diameter would be about right.

BTW if you like this idea and are wondering why the bungs should be short and not long, it is because of the bending loads in the tubes; these will be concentrated near the end of a longer bung and may cause a failure in the carbon. This kind of fracture is seen often in things like golf clubs, if the bonded joint hasn't been well designed.

cheers
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bikes4two
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Re: Trek Madone CF-BB liner/shell replacement?

Post by bikes4two »

Brucey wrote:I think it is quite likely that the problem had been developing for at least as long as the ST BB unit had been installed. The vendor may well have known or suspected that there was a fault. Did you ask the Trek dealer about the adhesives and sealants you found? It could be that the sealant wasn't OEM but a bodged repair.


The local Trek dealer did indeed suspect a bodge although he made no specific comment about the sealant/adhesive side of things.

Brucey wrote:If you fit a new threaded sleeve there is no reason to glue the new BB cups into the sleeve; there is no point in doing that at all.


Agreed, providing I can get a replacement sleeve? The LBS said Trek wouldn't supply such an item although a reply from Trek customer service an hour ago intimated that that wouldn't be the case if the sleeve was still available.

Brucey wrote:Unlike your LBS I'd be optimistic about bonding a new sleeve in to the frame. A good adhesively bonded joint, loaded in shear, has a static strength of ~ 1 tonne per square inch. What I'd not be so optimistic about is that the CF around the BB shell isn't at all damaged.


I share your optimism about being able to bond in a new sleeve, but getting one might be the problem. If I can't get a new sleeve then I'll consider salvaging the old one as follows:
a. The old sleeve is split more or less around the circumference in the middle area.
b. The threaded parts are undamaged so if I cut the old sleeve right through I could with the aid of a suitable length of new tubing whose OD matched that of the ID of the old sleeve, bond the parts together to form a replacement sleeve. The new length of tube joining the two old parts would preclude the use of a ST BB, but given the earlier discussion, I wouldn't want to :roll: However, a Hollowtech II axle wouldn't be obstructed by this piece of new tube, so there you go. :wink:
c. The salvaged (now repaired) BB sleeve can then be bonded back into place and hopefully give some useful service life?

I like the idea of the bungs to give increased surface area for bonding the BB sleeve to - what materials might be candidates for the bungs?

Cyleruk,
That's a interesting link, thanks, but this product wouldn't work on this frame as the BB frame orifices are only 38mm in diameter.

So I'm currently searching for bonding agents/adhesives and a replacement sleeve. On this latter point, I've yet to contact Ceeway.com as suggested 'up thread'.
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bikes4two
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Re: Trek Madone CF-BB liner/shell replacement?

Post by bikes4two »

bikes4two wrote:So I'm currently searching for bonding agents/adhesives and a replacement sleeve. On this latter point, I've yet to contact Ceeway.com as suggested 'up thread'.


Well I'm jiggered, I've just visited ceeway.com and.....
temp.jpg


Item 'BBSleeve68.38' seems just what I'm looking for :) :) :)
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Brucey
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Re: Trek Madone CF-BB liner/shell replacement?

Post by Brucey »

well that looks like just the ticket to me.

Time to get the araldite out then.

If you want to try bungs as I suggested earlier, aluminium or steel would be OK.

But then again if you try it without and it doesn't work, maybe you can have another go anyway....?

cheers
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ChrisButch
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Re: Trek Madone CF-BB liner/shell replacement?

Post by ChrisButch »

I've been following this thread with a lot of sympathy, since the nature of the bond between the liner and the carbon shell becomes of urgent interest, as I have found, if you have a BB which you need to remove but is reluctant to shift - do you take the risk of using some of the more aggressive usual methods in such circumstances, when what gives way might be the liner/frame joint rather than the BB/liner joint? I found myself in this dilemma with my first carbon frame a few years back. Unless detailed information about the liner and its fixing is available from the manufacturer (as appears to be the case here with Trek), you feel a bit like the bomb disposal man deciding which lead to cut in The Poseidon Adventure
whit3sh33p
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Re: Trek Madone CF-BB liner/shell replacement?

Post by whit3sh33p »

Hey Bikes4two

Did you ever solve this problem? I've got a very similar issue (the sleeve is completely cracked, one half is rotating inside the shell, the other remains stuck).
Help!!
tim-b
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Re: Trek Madone CF-BB liner/shell replacement?

Post by tim-b »

Hi
There have been a few different threads on this, which I think are the same BB
viewtopic.php?f=5&t=82038 replacement
viewtopic.php?f=1&t=82147&hilit=bb+sleeve+trek suitable glue
viewtopic.php?f=5&t=82599&p=737995&hilit=bb+sleeve#p737995 the fix
How successful has it been? I don't know...
Regards
tim-b
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bikes4two
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Re: Trek Madone CF-BB liner/shell replacement?

Post by bikes4two »

Hi All,
I'm the OP of this thread. I haven't been out on the Trek much until recently and I've done just over 300 miles on the repaired BB.

Many of the miles have been over the hilly South Downs and I often get out of the saddle to cope - and I'm 95kg so lots of pressure on the cranks.

As of Saturday I can report that there is no visible lateral movement of the cranks whilst 'honking' (I often look down at the chain rings/FD to observe any movement).

I have a word document outlining the repair - just PM me if you'd like a copy.
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bikes4two
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Re: Trek Madone CF-BB liner/shell replacement?

Post by bikes4two »

bikes4two wrote:Hi All,
I'm the OP of this thread. I haven't been out on the Trek much until recently and I've done just over 300 miles on the repaired BB.

Many of the miles have been over the hilly South Downs and I often get out of the saddle to cope - and I'm 95kg so lots of pressure on the cranks.

As of Saturday I can report that there is no visible lateral movement of the cranks whilst 'honking' (I often look down at the chain rings/FD to observe any movement).

I have a word document outlining the repair - just PM me if you'd like a copy.


Just to say that it's more than two years since the repair and maybe a couple of thousand miles on the Trek Madone (not my most used bike by any means :roll: ) and the repair job is still holding with no noticeable degradation.

I had some PMs from others who had the problem and sent them the repair procedure I'd used - hopefully they have enjoyed the same level of success?

I am completely confident that the repaired BB is stronger than the factory supplied version. :shock:
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Stefgloyn9
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Re: Trek Madone CF-BB liner/shell replacement?

Post by Stefgloyn9 »

Bikesfor2 I am currently experiencing the same issue with my 2012 Madone, can I please request the word document you have created? I have managed to remove the old BB sleeve and have ordered another from ceeway but need help on how to bond it etc. Any help you can give would be appreciated. Email is stef.gloyn@hotmail.co.uk. Many thanks
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