Any consensus as to whether headset cups should be greased or not before fitment to carbon frames?

Grease or anti-seize (but not copper grease)

Grease

Mounted in carbon or metal cups ? The rest of the frame is immaterial IMHO

Thanks all.
I just assumed the cups would be in bare carbon – not actually stripped down yet – just maddeningly creaky and think its coming from front end. Sounds like my new carbon super bike is about to snap into a thousand pieces…

Fully synthesis grease. I believe petroleum based products can have an adverse effect on the resin used in carbon.

I’d just go with a bike specific teflon fortified grease as it will stay put better.

Carbon frames are very good at transferring noises around the bike and tricking you into thinking it’s coming from somewhere else.

Yeah – well aware the sound could be ‘bouncing’ around the frame and tricking me but have done the whole seated/standing/no hands pedalling/no feet bouncing on saddle options which makes me think its definitely front end based.

Carbon prep, not grease.

I wouldnt use the gritty carbon assembly stuff as a headset should be a very close tolerance so no room for the coarse particles and you could do harm.

Concur. And seems we have consensus that a touch of grease is the way to go. Will do that tomorrow and see how we go. Cheers 🙂

Use carbon paste or fibre grip is good will stop any noises appearing

Interesting, dropped the bearings into the cups on a mojo and tranny and its been as good as gold. No grease on the bearing /cup at all…

Re: Santa Cruz Highball, it says…..

SHOULD I GREASE THE HEADSET CUPS WHEN I INSTALL THEM?
Yes, we recommend this. Do not use the Carbon Assembly Compound on the headset, as it will make it more difficult to remove from the frame.

Just looking into this myself. Being somewhat OCD, I can never take a vague answer, and ambiguity annoys me a lot.

There is a lot of conflicting info about:

http://forums.roadbikereview.com/components-wrenching/fyi-grease-carbon-seat-posts-40455.html
http://www.bikeradar.com/forums/viewtopic.php?p=15993952
http://weightweenies.starbike.com/forum/viewtopic.php?f=3&t=119994

So really, what the heck do we use as an assembly compound (grease is too general a word iMHO) for aluminum (aluminum) headsets pressed into carbon fibre (fiber) frames?

+ everyone says DO NOT use Carbon Assembly Compound (gritty paste)
+ Santa Cruz say use use grease
+ Easton, Campagnolo, Deda, Bontrager say don’t use grease

Looking into it a bit, I think what I am going to use to press aluminium cups into a carbon frame is Dow Corning 7 Release Compound. This is a silicone grease that is neutral on rubber and plastic, and so should be totally fine on carbon and aluminium. It is very water repellent (takes ages to remove from skin, soap and water not very effective). Its viscoelastic properties suggest that at short flow times (or low temperatures), it acts like an elastic solid, similar to rubber. This seems to be ideal for this application. Luckily, I have a tube of this in my arsenal (used for replacing rubber bushings on old monosynth keyboards).

Still looking into what to use on titanium / aluminium, aluminium / amuminium, and steel / aluminium surfaces!

Before you strip it down, I had a creaking from my carbon road bike and was the rear brake ferrule in the side of the head tube/ top tube moving and creaking. Also check the bottom bracket for sound resonance moving through the frame.

For a couple of seasons, my BB creaked like mad. Turned out to be the stem/bars interface which needed a dab of copper splodge.

It is a jolly game tracking down annoying noises…

My carbon Santa Cruz was the same, v nearly changed the cups. Turned out to be Hope Head Doctor. Changed to star nut and all is quiet again…

Interesting.

I stripped front end down today and was half expecting the cups to just fall out of the frame the noises had been so bad. But they were fine. Just cleaned everything and greased well and replaced 4 off 5 mm spacers with 1 off 20 mm spacer (stiffer) and car park test seems positive. Happy days 🙂