Bicycle Mechanics - carbon post, chomoly frame and grease

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sunburst
10-25-08, 01:01 AM
OK, I searched first and read many threads about carbon seatposts seizing in an aluminum frame, or alum post in carbon frames. But I've got a chromoly frame - Reynolds 531 (that is chromoly, isn't it? ... or a different alloy?)

Tomorrow, I want to remove my alum seatpost, and install a carbon post I got in trade tonight.
Do I grease, or not? and if not, do I have to super-clean the seat tube? Some threads say yes, some say no.

Btw, I this is a loooong Specialized mt. bike seatpost (carbon wrapped aluminum?) - about 350mm I think. I appear to need less than half of that for my road bike. Would you guys cut, or just let all the extra post sit in the seat tube?


Panthers007
10-25-08, 03:03 AM
If you read all the threads on this - as I did (and many other places as well) - then you know that there are those who swear it will cause horrible problems, and those who claim it won't hurt a fly. So no one really knows that either of us have met. I see no evidence to support the allegations that it will cause problems. But...

There isn't any harm in NOT getting grease on the seatpost. And there might be a chance it can cause damage. So when I installed one on my CrMo 531 bicycle (yes I have one also) a few months back - I just gave it a small shot of Teflon spray. I just had occasion to adjust the seat height, and it came right out without a hitch. So in a couple months there has been no discrnable damage from this approach.

That's my 2 cents.

theextremist04
10-25-08, 05:30 AM
When in doubt, carbon assembly paste is best; the tacx stuff is good. Head down to your LBS and ask if they have any.


julk
10-25-08, 06:55 AM
+1 for the Tacx carbon assembly paste.

I have used it for 2 years on a carbon post in a steel frame and no problems.

HillRider
10-25-08, 07:21 AM
Just for the record, and having nothing to do with the grease/no grease question, Reynolds 531 is a Manganese-Moly alloy, not a Chrome-Moly alloy.

operator
10-25-08, 08:52 AM
If you read all the threads on this - as I did (and many other places as well) - then you know that there are those who swear it will cause horrible problems, and those who claim it won't hurt a fly. So no one really knows that either of us have met. I see no evidence to support the allegations that it will cause problems. But...

There isn't any harm in NOT getting grease on the seatpost. And there might be a chance it can cause damage. So when I installed one on my CrMo 531 bicycle (yes I have one also) a few months back - I just gave it a small shot of Teflon spray. I just had occasion to adjust the seat height, and it came right out without a hitch. So in a couple months there has been no discrnable damage from this approach.

That's my 2 cents.

That's too bad, because people make carbon specific assembly compounds - e.g

Tacx

https://images2.bikebuster.dk/imageuploads/370108/product_370108.jpg

Finish line

http://www.ebikestop.com/prodimages/LU2567.jpg

mcoomer
10-25-08, 09:51 AM
Tacx carbon assembly paste FTW!

Panthers007
10-25-08, 03:08 PM
Personally - I can't wait for this Carbon-Age silliness to come to an end, and Reynolds 531, or similar, to come back in a big way. Though I'll miss laughing when someone hits a pothole on their $5,000 Whatsit frame and carries their ex-machine home on a baggie.

<go ahead - throw rocks at me, but that's my opinion>

Mondoman
10-25-08, 04:32 PM
Seems to me that you would at least want to coat/treat the inside of the seat tube with something to prevent rust, as the seat tube opening is a likely entry route for water.

sunburst
10-25-08, 11:53 PM
I went to one of my LBS's today. They had FSA's carbon assembly stuff - $4.95 for what appeared to be a teaspoon in a small square plastic bag. Jeeezus! Didn't even look like a resealable bag, so for all I know, it was meant for a single application. So, I passed. I'll look for some Tacq. Finish Line has something similar, so whichever one I can find.

When I got home, I looked at the post. Right at the bottom, it said "Do Not Use Grease."
OK, I won't.

sunburst
10-25-08, 11:55 PM
Personally - I can't wait for this Carbon-Age silliness to come to an end, and Reynolds 531, or similar, to come back in a big way. Though I'll miss laughing when someone hits a pothole on their $5,000 Whatsit frame and carries their ex-machine home on a baggie.

<go ahead - throw rocks at me, but that's my opinion>

I've got six bikes. Five steel, and one carbon. The way the summer has gone, I ended up riding the steel bikes much more. Hadn't been on my carbon Giant in a long time. Yesterday, I took it for a 3 hour ride in the hills, and man, it felt perfect from the start to the end of the ride.

Got on my old steel Trek today and it felt great too, but the Giant OCR carbon frame is amazing.

But I know what you mean about carbon being breakable. Did you see the guy in the Tour de France who hit the isle in the middle of the road? He went straight up and his bike came down in two pieces. The announcers were besides themselves - quite a sight.

The seatpost I traded for, is carbon wrapped aluminum (what's the point? - looks?, bragging rights?), so presumably it is stronger than a pure carbon one.

z415
10-26-08, 01:21 AM
Just for the record, and having nothing to do with the grease/no grease question, Reynolds 531 is a Manganese-Moly alloy, not a Chrome-Moly alloy.

Manmoly, lol.