Ti wins

When did you notice that there might be a problem?

But you lose cos you spent mega bucks on a ti frame!!

Took the bike down off the wall yesterday morning to go to work and the cranks wouldn't spin. A wee bit of heaving later, there was a loud *crack* and then they were free. However, I had a wee look and noticed that the drive side BB was spinning with the cranks….

Oh and £360 ain't megabucks

/pedant mode/ The Ti used in bike frames is an alloy as it is a mixture of other metals. Did you mean "titanium alloy vs Aluminium Alloy"
/pedant mode/

I used to have mm deep grooves worn into a Litespeed titanium frame frame caused by rubbing PLASTIC-coated cables (with no corresponding damage to the cable(?) , and a deep groove caused by the RUBBER tyre rubbing under power on the inside rear stay.
Materials are funny things.

OP – looks morelike "Ti vs. crappy installation"

*runs*

west kipper – the plastic grips dirt that then rub into the metal.

And the moral of this story? Use Ti-Prep/Molly Grease/Copper Grease when installing anything on a ti frame.

(cue lots of other alternative morals to this story fuelled by the inevitable and endless 'ti is overpriced rubbish' and 'my material is better than your material' gangs that seem to inhabit STW!)

How would that have helped? Do you know the cause of the failure?

Yes, I realised that cynic-al, though I'm still surprised that the dirt was tougher than Ti (maybe we should make frames from dirt?)
BTW, I'm glad you dropped that first sentence with druidh yourself- I was thinkin' it 🙂

Given the force required, the loud crack and the remnants of material left on the bb threads, this looks like a clear case of bi-metallic corrosion. Ti and alloy are famous bed-fellows for this. Over time the components of the 2 materials fuse together at a molecular level and almost become 1 component. This is the classic cause of alloy seatposts becoming stuck in metal frames (and the reason why Seven put a unidirectional carbon fibre sleeve in their ti frames, so there is no metal-to-metal contact).

The best way to stop it is to introduce some sort of barrier element that counteracts the process. Moly grease is probably the best of all as it works on a molecular level, is completely inert and resistant to heat, moisture and force. I have used it for years on all threaded metal-to-metal contact points, and wherever bi-metalic corrosion could occur and have never had a problem. Even after months and years of all weathers riding, components come apart easily, and just need a wipe of the threads to come up as good as new.

It looks like the threads from the BB have come off in the frame. Is that right? Can the threads (in the frame) be chased clear?

Dirt = broken up rocks. Ti ain't that hard.

druidh needs to be kept in line 😡 otherwise he gets all C2W nazi 😀

Copper grease was used during installation. Mind you, that was 2 years – and a good few miles – ago. The bearing has actually seized solid and the threads in the BB shell are still perfect 🙂

solarider, you're only coming up with the defence because of your vested interest- we all have seen how you own 78.3% of the world titanium frames. 🙂

Copper grease won't last 2 years, as you can see from the picture. There is no trace of it left. Next time, re-apply more frequently or go for Moly Grease. Like any of these:

http://shop.ebay.co.uk/items/__molybdenum+grease_W0QQ_dmdZ2?rvr_id=&crlp=3020810357_229447_229457&UA=WXI6&GUID=b928754e1270a0e201d459d4ffd61c64&agid=1020327707&MT_ID=10&keyword=molybdenum+grease&ff4=229447_229457

Stays put for years.

Don't know what you mean (and it's 78.4% by the way).

I should really edit the above post before anyone comes along and starts arguing that HTII BBs can't possibly last 2 years anyway.

solarider – thanks for the advice. I'll try to remember. The NDS BB came out a treat btw.

My apologies druidh – it was crappy maintenance 😀

Maintenance?

I'll have to go google that….

I wouldn't bother at the rate you replace your bikes 😛

I didn't really see myself as one of the serial bike changers…

ChiTi – 2 years and no intention of changing
Cayo – 2 years. Might look for an end-of-year bargain later this year *cough*
Blur – Last summer, but had the Meta for 3 years before that?
Sutra – 4 years and just recently replaced.

How many new bikes have you had these last 12 months Al?

Thing is, I wouldn't have had any BB in a Ti frame for so long without occasionally doing a strip down, usually Ti bikes start creaking sooner than other metals, especially if they're used in the rain-do you live anywhere it rains druidh?. 🙂
Its one of the massive benefits of HT2, the job takes minutes, so its not even much hassle.

Heh, I knew you'd bite. You've bought 2 in the last 12 months?

I'm on 3 I think, though I don't count the Heckler as I had one before.

Heckler 2005 – present (bar Nomad for 1 year)
Shand 2006 – present
Ritchey 2004 – 2009 (Principia)
Hewitt 2003 – 2009 (Salsa)

Looking at that I think you've changed bikes mpre than me in the last few years 😛

Why do people use Copa Slip / copper grease on bikes?

Aye, its horrible stuff that makes the bike look like its weeping rust from the threads.

cynic-al – Member
Heh, I knew you'd bite. You've bought 2 in the last 12 months?

I'm on 3 I think, though I don't count the Heckler as I had one before.

Heckler 2005 – present (bar Nomad for 1 year)
Shand 2006 – present
Ritchey 2004 – 2009 (Principia)
Hewitt 2003 – 2009 (Salsa)

Looking at that I think you've changed bikes mpre than me in the last few years

Probably right – it's just that some folk seem to get turn over their bikes a lot more often than me…..

Dirt is ground up minerals, and minerals are very hard indeed. No good for frames of course since they are brittle.

That's why dirty chains wear very very fast, because the grit is so hard.

Why do people use Copa Slip / copper grease on bikes?

See my post above. Prevents this kind of bi-metallic corrosion. The copper acts as a kind of inert barrier between 2 metals that would otherwise fuse. It's no a lubricant, so can;t be used on moving parts. It's just for static parts. Moly grease is better though.

I am a big user of coppaslip. I have heard it said on there that it causes catalytic corrosion but I use it all the time on dissimilar metals. Anyone got an explanation for this tendency to cause corrosion?

Bolts that might work loose or are safety critical – loctite.
Nuts and bolts of the same material – moly grease
Bolts bolted into disimilar metals (ie Steel caliper bolts) – coppaslip

I never have issues with stuff seizing – motorcycles or bicycles. Mind you I was appalled that my new bike had been assembled with a lot of dry threads. Some corroded after a few months – I stripped the entire bike to reassemble properly

Copper grease is for high temperature conditions.
Copper grease, does it not cause galvanic corrision?
The picture in the OP looks a lot like galling.

Previously called Ti Prep

"Copper grease won't last 2 years"

Rather a sweeping statement. Where is it going to go then? Can't get washed out trapped between threads, if applied correctly it's still visible upon dismantling whatever the time period.

Corrosion usually takes place where stuff stays wet (eg being sprayed by road salt). I've not researched, but my guess is coppaslip is better than nothing in this sense but it's non-conductive properties will get ****ed up the arse by grease.

Coleman – Member
> "Copper grease won't last 2 years"

Rather a sweeping statement. Where is it going to go then? Can't get washed out trapped between threads, if applied correctly it's still visible upon dismantling whatever the time period.

I should point out that I did actually clean the BB shell before taking the photo – just to make it easier to see the damage.

Finish Line Anti Seize is that not Bostik Never Seize, which is not copper based.

Campagnolo recommend Loctite 222 Threadseal for BB threads.

What part of a bike gets up to the temperatures that needs copa slip?
http://www.molyslip.co.uk/anti_sieze_compounds/

From the molyslip site..

A single application of Copaslip (often misspelled as copperslip or coppaslip) or Alumslip will stop metal fusion for many years.

Many=>2??

Is copper a good conductor?
http://www.stainless-steel-world.net/titanium/ShowPage.aspx?pageID=173

Campagnolo Loctite 222 thread lock/seal
http://www.youtube.com/watch?v=fAHd2amwskU&feature=related

Galling
http://www.finishing.com/Library/titanium.html

The poor thermal conductivity of titanium also cortributes to the galling problem.

Macavity – Member

Copper grease is for high temperature conditions.

that would make sense – exhaust studs on motorbikes and brake mountings is two common places – ordinary grease would boil / burn away but the copper would remain.

Copper grease, does it not cause galvanic corrision?

So I have heard said on here but I would like to hear a bit more explanation as it doesn't IME

"Copper grease won't last 2 years"

Rather a sweeping statement. Where is it going to go then? Can't get washed out trapped between threads, if applied correctly it's still visible upon dismantling whatever the time period.

Are you kidding? There are 2 places that water washes into your frame. Firstly down the seat tube (from the back wheel), and secondly through the bb (from the front wheel). Regardless of wherever and however it enters your frame, the bb is the lowest point in your frame and where all water eventually collects. It absolutely will make its way between threads and wash out copper slip. In extreme cases (and I am not accusing the OP here), the bb can literally be submerged in water inside the frame.

That's why Phil Wood (RIP) bbs, which are reknowned for their longevity, use submarine bearings. It's also why so many frames have drain holes under the bb shell, to release any water which would otherwise wash out grease around the threads and the bearings from the inside out.

Have you not ever removed a bb and released at least a little water, or found the shell covered in mud (the residue from dirty water having found its way down there)?

It's simple physics. In descending order of density you have solids, liquids and then gasses. Since a liquid (in this case water) is less dense than a solid (in this case copper slip), it will find its way in there.

Moly resists water and friction better than copper grease. In either case, a regular re-application would be advisable, but what constitutes 'regular' depends on how regularly the bike gets ridden in the wet.