's Forum Archives - General

Archive Home >> General(1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 )

Grease on carbon seatpost and steerer, why can't I?(4 posts)

Grease on carbon seatpost and steerer, why can't I?AaronL
Jul 14, 2003 10:39 AM
Can someone please explain to me why this is supposed to be such a big no-no? I don't get it. I greased the carbon seatpost on my Litespeed, as well as the steerer, so they won't creak. No problems so far.

re: Grease on carbon seatpost and steerer, why can't I?davet
Jul 14, 2003 10:56 AM
I believe the main problem with greasing CF is in the using of petroleum based products. It can wick into the fibers and cause them to delaminate(?). Synthetic greases apparently don't cause that problem.

The original reason for not greasing CF is that CF has no chemical reaction with metals, grease therefore is not necessary.
re: Grease on carbon seatpost and steerer, why can't I?jw25
Jul 14, 2003 11:39 AM
I think the main reason is overtightening. Since the epoxy finish on CF parts is so slippery, greasing them means you need to overtighten them to prevent slippage. Overtightening greatly increases the risk of breaking fibers, which causes a stress point, and increases the chances of failure.
Grease is used to eliminate electrolytic contact, but in this case, the epoxy serves to prevent contact between the metal and fibers, so corrosion shouldn't be a problem.
I've also heard of petroleum products affecting the epoxy bond, which could cause failure. Synthetic greases may or may not cause this, but something inert like a silicone grease should be perfectly safe. Silicone grease is used in the food industry, because it's non-toxic, and while somewhat expensive, it will do the trick. I used some in my headset cups to get rid of a nagging creak. It's been 1500 miles now, and no problems (on a 1" Columbus Muscle fork - if it's going to fail, it would have by now).
Cool, I use Mobil 1 Synthetic...AaronL
Jul 14, 2003 12:16 PM
And the only reason I grease the post and steerer is to not have any creaks.