Thread in bottom bracket loose in carbon frame

bikeboff

I noticed that my crankset was wobbling, so I replaced my bottom bracket, only to realise then that the problem was more severe. The actual thread in the bottom of the frame is loose - the metal (aluminium) core is moving around inside the carbon frame. I presume it has become unstuck, unbonded, and has worked loose.

As luck would have it, this frame has a five-year warranty, but I bought it six years ago.

Has anyone experienced, or come across, a similar problem? I am wondering whether this is fixable, or whether I might have to ask the manufacturers very, very nicely whether they might be able to help?

andy_wrx

The alu BB shell come loose in one side of my 2006 Roubaix last month

Spesh wouldn't have it as a frame warranty issue, said it was due to corrosion, so I've reframed it with something nicer

bikeboff

Did you make any enquiries about getting it fixed, Andy, or did you see it as a nice chance for an upgrade?

Monty Dog

Even if it was due to corrosion, it's still down to poor quality manufacture and I'd hope covered by a lifetime warranty - but don't hold your breath. Depending on the BB construction it may be repairable but would typically involve drilling holes in the BB shell and injecting some epoxy resin

russyh

Whilst not ideal I would think that's not a particularly difficult repair. It would of only been bonded in with epoxy resin in the first place. If it were me I would buy a marine epoxy handpack from a boat chandler something like this
http://www.pinbax.com/index.asp?selecti ... ct=9&sc=15

If you warm the epoxy on a radiator you will thin it out slightly so you could inject it in fairly well. Worth giving it a go if the frame is other wise written off

Monty Dog

I've used this to successfully repair damage to carbon wheels:
http://www.easycomposites.co.uk/product ... fibre.aspx
It's quite runny when mixed so feasible to put into a syringe and pump into a hole

tuneskyline

I had this exact thing happen. The frame builders were happy for me to send my bike to a very well established carbon repair shop to see if they could fix it. They did fix the thread back in but it came loose again after a few days. I got a free replacement frame. I would just go for a new frame. Even though your warranty is up a few nice words and a few subtle hints that you post on bike forums might make them see things your way. It worked for me.

andy_wrx

bikeboff wrote:

Did you make any enquiries about getting it fixed, Andy, or did you see it as a nice chance for an upgrade?

I swapped the frame for something more interesting

It was 7 years old and a bit tatty, minor stonechips and scratches

Partly it was an excuse to upgrade, partly because I wanted it fixing quicker rather than send-off and wait for repair.

Even if it is just a 'glue it back' job, it needs to be bonded back square to the other side so the two cups are parallel, or facing.

andy_wrx

Monty Dog wrote:

Even if it was due to corrosion, it's still down to poor quality manufacture and I'd hope covered by a lifetime warranty - but don't hold your breath.

My thoughts entirely.
If due to corrosion, then surely it was not sealed properly at manufacture, or inadequate bonding/sealing products were used ?

Ironically it was my 'summer bike' anyway, so didn't get wet and caked with muck every time out like the 'winter bike' does

on-yer-bike

Apparently there can be galvanic corrosion between aluminum and carbon because carbon is an electrical conductor. So its up to the manufacturer to somehow isolate the alu. I guess there are some scientists here that can explain this better.

Burton

I had the same thing happen on my Bianchi 928L, one year out of warranty!
Tried to get somewhere with Bianchi but no luck, I also enquired about a fix (work with clever carbon specialists!) In the end I went down the new bike route too.
The Bianchi is still hanging in the shed awaiting the day I either repair it or bin it, shame because it's a lovely frame.

bikeboff

So, I've made a few enquiries, through the shop where I originally bought my bike (a Viner), and also in my LBS. I'm not sure Viner really exists any more, and it was (just) out of warranty anyway, so I think that route is dead.

I am going to strip the frame though and send it to a firm of carbon specialists called HQ Fibre, near Norwich. They have been recommended to me, were very friendly on the phone, and seemed to think a repair should be fairly straightforward for a modest cost. If that's the case I'll be delighted - I didn't want to replace the frame, tempting though an upgrade always is.

Monty Dog

on-yer-bike wrote:

Apparently there can be galvanic corrosion between aluminum and carbon because carbon is an electrical conductor. So its up to the manufacturer to somehow isolate the alu. I guess there are some scientists here that can explain this better.

Anodising of the aluminium alloy very effectively protects against the effects of galvanic corrision, plus if it is effectively bonded in place there should be no room for water ingress which accelerates the process. This has been a known issue for 25 years so there's no excuse from manufacturers - many still fit unfinished alloy inserts to save a few pence.

mr_evil

Monty Dog wrote:

Anodising of the aluminium alloy very effectively protects against the effects of galvanic corrision, plus if it is effectively bonded in place there should be no room for water ingress which accelerates the process. This has been a known issue for 25 years so there's no excuse from manufacturers - many still fit unfinished alloy inserts to save a few pence.

Anodizing only works as long as it remains totally intact - I recently pulled most of an anodized aluminium bolt out of my Ti frame's BB. I had hoped it would be safe, but presumably threading it in scratched through the insulating layer, and since BBs tend to get very wet... Thankfully the frame was undamaged by it.

It's my understanding that it is common to use a layer of glass fibre between carbon and Al to insulate them.

Monty Dog

I have experience of galvanic corrosion of aluminium components and carbon fibre - except it involved artificial limbs and bodily fluids as I was an in-house designer for a manufacturer of body parts! Conditions were far worse than most bike parts will endure and decent anodising of the alloy parts eliminated the issue - we tested lots of options at the time but it took a few more years for bike manufacturers to catch up.

bikeboff

It's good to know that the technology for body parts is ahead of that for bikes. My right shoulder is held together with kevlar tightropes - I hope they'll last longer than my carbon bike frame.

rhnb

I had a similar problem on a BB30 frame. The drive side alu insert unbonded itself from the carbon frame.
I eventually found this guy - 'rob@carbonbikerepair.co.uk' after another carbon bike repairer said that they no longer repaired bbracket bonding problems as they'd had too many sent back after failing again.
So, it was basically junk the frame or give him a go, so thought it was worth a punt.
Happy to report that this was just over a year ago, and I've had no further issues with it. He removed both inserts and re-bonded them. Take a look at their website ( http://www.carbonbikerepair.co.uk/ ) and maybe drop him a line and see what he thinks?
Good luck!

craker

A hacky fix for an older steel frame is one of those sleeved bottom brackets where one side screws into the other. I had to chamfer an edge on the inside of the shell but its been a working fix for me for a year. Square taper only AFAIK. Worth a try at less than £20?

bikeboff

An update on the outcome for me and my carbon frame. It has come back now from HQ Fibre in Norfolk, and they have successfully fitted a new steel shell in the bottom bracket for £111 all in. It looks solid. I'm going to have my bike rebuilt now (it needs some new cables etc), and it should be ready to ride again next week. Assuming this has been successful I am very pleased indeed to have rescued my frame.

crankycrank

Sounds like a good solution for a reasonable price. Please keep us updated if it happens to fail again as I am curious as to how long a good repair might last.

marcusww

on-yer-bike wrote:

Apparently there can be galvanic corrosion between aluminum and carbon because carbon is an electrical conductor. So its up to the manufacturer to somehow isolate the alu. I guess there are some scientists here that can explain this better.

It would most likely be the aluminium corroding itself in the presence of an electrolyte - probably water. Carbon in any corrosion situation would be the conductor between two unlike metals. But in a BB area I don't think there would be any other metal in inside the frame in proximity to the BB. the Frame manufacturer should have sealed the aluminium inside the frame in some way.

I was a marine corrosion engineer - Carbon Yachts presented real problems

phil485

So resurrecting an old thread.

I've just noticed the shell on my felt is loose, couldn't loosen the bottom bracket when I was trying to do some maintainence.

Am I going to damage the frame more if I ride it?
Anyone know how good felts warranty process is?
Anyone in the Surrey area who would be able to take a look at it?

reg_

andy_wrx wrote:

The alu BB shell come loose in one side of my 2006 Roubaix last month

Spesh wouldn't have it as a frame warranty issue, said it was due to corrosion, so I've reframed it with something nicer

Strange for Specialized?

bikeboff

An update, three months on. The repair has been excellent so far - my repaired carbon Viner rides like a new bike. Very happy indeed with the outcome here.

andy_wrx

reg_ wrote:

andy_wrx wrote:

The alu BB shell come loose in one side of my 2006 Roubaix last month

Spesh wouldn't have it as a frame warranty issue, said it was due to corrosion, so I've reframed it with something nicer

Strange for Specialized?

They've lost a customer...