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Pressing bearings into a carbon frame

Nov. 30, 2016, 3:28 p.m.
Posts: 1173
Joined: Jan. 9, 2005

I am about to press new bearings into my Giant. I was wondering what to use for lube between the bearing and the carbon. Should I use grease or anti seize?
Thanks

Nov. 30, 2016, 3:46 p.m.
Posts: 1143
Joined: Sept. 30, 2006

Im not really sure if this is the correct application for carbon assembly compound?

https://www.mec.ca/en/product/5048-689/SAC-2-Super-Carbon-Alloy-AssemblyCompound-4oz-113g

Nov. 30, 2016, 3:57 p.m.
Posts: 17771
Joined: Oct. 28, 2003

Im not really sure if this is the correct application for carbon assembly compound?

https://www.mec.ca/en/product/5048-689/SAC-2-Super-Carbon-Alloy-AssemblyCompound-4oz-113g

Definitely not. Carbon assembly compound is to make things like a seatpost or handlebar not slip.

Increases friction between 2 slippery surfaces, yielding tighter grip. Great for carbon, aluminum or steel seatposts, handlebars and stems.

Note, grip aided by small bits of hard silicone, which can cause cosmetic blemishing. Do not use on threaded parts or for bearing lubrication

Nov. 30, 2016, 4:07 p.m.
Posts: 17771
Joined: Oct. 28, 2003

http://si.shimano.com/php/download.php?file=pdf/dm/DM-MBFC001-00-ENG.pdf

Shimano instructions have grease for a threaded BB and no grease shown for a press fit.

Nov. 30, 2016, 7:20 p.m.
Posts: 5731
Joined: June 24, 2003

Loctite 641 sleeve retainer. Recommend by some sites for pressing bb bearings into carbon frames.

Debate? Bikes are made for riding not pushing.

Nov. 30, 2016, 7:30 p.m.
Posts: 152
Joined: Feb. 13, 2016

I always use grease to keep them from creaking and help them slide in place. I read somewhere the grease should be 'carbon compatible' but I'm not sure which is or is not. That said I generally us Phil Wood waterproof grease on my carbon frame and it hasn't melted or shattered - yet =)

Nov. 30, 2016, 7:52 p.m.
Posts: 0
Joined: Aug. 12, 2007

There's so few hard facts out there with regards what you should or shouldn't do.

Personally I'm not a fan of slamming it in dry…. Sure It'll go in fine, but will it come out again in 2 years time (or 2 weeks time being a press fit BB ;) ). Nothing wrong with grease and I don't know of a grease that isn't 'carbon friendly'. Not sure how that rumour started but always worth reading the label if in doubt. If the old BB comes out a bit too easily I'd be tempted to use a retaining compound and primer if needed. Worth noting that if you do this, you should leave time to allow it to cure once installed.

PTFE paste is sometimes recommended too.

I don't know of an obvious reason not to use anti-seize but it tends to be used with titanium to stop galling. It's also messy!

So IMHO it all boils down to the tolerances in question as to what you should use.

Don't use 'carbon prep'!
Don't use strong threadlocker!

treezz
wow you are a ass

Nov. 30, 2016, 9:27 p.m.
Posts: 152
Joined: Feb. 13, 2016

There's so few hard facts out there with regards what you should or shouldn't do.
………………….
Don't use 'carbon prep'!
Don't use strong threadlocker!

x2 on don't use thread locker. I don't know about the resin in carbon frames but I know small screw thread locker (Loctite 222 for sure) causes certain plastics to become brittle and crack.

For the same reason I would hesitate to use Loctite 641 unless as a last resort. The material technical data sheet does not talk about any specific use other than metal to metal and says "This product is not normally recommended for use on plastics (particularly thermoplastic materials where stress cracking of the plastic could result). Users are recommended to confirm compatibility of the product with such substrates."

I know carbon fiber is generally more of an epoxy resin than a plastic but I would not want to risk a $2000 frame on any assumption. That said, from reading other forums it seems as if quite a number of people are using it and I haven't heard of an epidemic of frames cracking as a result so….good luck:| Perhaps there is an industrial chemist or carbon fiber expert on these forums who could enlighten us?

Nov. 30, 2016, 9:45 p.m.
Posts: 0
Joined: Aug. 12, 2007

^ There's some good nerding on the subject here:

https://forums.cervelo.com/forums/t/9738.aspx?PageIndex=2

The summary being that Cervelo at least don't think it's a problem. Or basically no-one has a bloody clue :D Oh bike industry…..

treezz
wow you are a ass

Dec. 1, 2016, 7:58 a.m.
Posts: 6
Joined: Jan. 12, 2006

Every carbon frame I've seen has had aluminium sleeves at pivot points so that the bearings are actually sitting on metal rather than carbon.

I just put a thin film of grease on the sleeve [HTML_REMOVED] press away.

Dec. 1, 2016, 8:32 a.m.
Posts: 11
Joined: Nov. 20, 2005

I followed cervelo and wheelsmfg directions when I did pressed my BB…

… used http://www.parktool.com/product/polylube-1000-lubricant-tube-ppl-1?category=Lubricants%20[HTML_REMOVED]%20Compounds

Seemingly pretty standard lube. Along with big-ted, a thin film and press away.

Dec. 1, 2016, 12:41 p.m.
Posts: 1
Joined: Sept. 20, 2006

Apparently Finish Line qualified their greases for use on carbon.

Old Forum Answer

Dec. 2, 2016, 4:34 a.m.
Posts: 0
Joined: April 14, 2011

Giant recommend Finish Line Teflon grease for their carbon frames, whether pressing a BB, on headset bearings (including those sitting directly on the head tube seats), or suspension pivot bearings.

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