# How tight to tighten Carbon Seatpost?



## ringroadwarrior (Dec 8, 2002)

Well, I finally got all the grease out of frame. Now how tight should the coller be to hold the post in. I have a torque wrench but it will not hold my 4mm allen head. I dare not clamp it as tight as my Al. post was.


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## OokieCookie (Apr 8, 2004)

I just tighten mine until it feels good and solid. Basically just enough so that it wont move around at all when you're sitting on it. I tighten, and then try and rotate the seat. It gets to be one of those things where you just "know" where the proper tightness is. Experiment, but definitely err to the low-torque end of things.


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## Dinosaur (Jan 29, 2004)

*How is your sense of feel?*

Just about all the cf seat posts have recommended torque settings, but if you have a good sense of feel, use a 3 way hex wrench and tighten using your fingers until it's good and solid and the wrench starts to fex, then stop. But before you slam that puppy all the way in, check and make sure it won't get stuck. Like I said before, I used a LIGHT coat of grease with mine. Using grease you risk the chance of the post slipping, without grease, it could get stuck. If you have one of those ultra weight seat posts and you over tighten, you can crimp the post. My cf post came with instructions, recommending 12lbs with a torgue wrench and advised to have it installed by a bicycle mechanic if in doubt. I've never had problems with mine one way or the other........


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## johnny99 (Apr 2, 2004)

Dinosaur said:


> Using grease you risk the chance of the post slipping, without grease, it could get stuck..


The reason to grease is to prevent a metal post from reacting with metal in your frame. A carbon post does not have this problem and should not be greased. Follow the torque recommendation for the post. If it slips, tighten 1/4 turn at a time until it doesn't slip any more.


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## Dinosaur (Jan 29, 2004)

*Sorry...*



johnny99 said:


> The reason to grease is to prevent a metal post from reacting with metal in your frame. A carbon post does not have this problem and should not be greased. Follow the torque recommendation for the post. If it slips, tighten 1/4 turn at a time until it doesn't slip any more.


I installed my cf post first time around with no grease, rode through the winter and when I pulled it out a couple of weeks ago there was rust forming on the inside of my seat tube. Maybe the cf post needs no grease, but the inside of a seat tube on a steel bike needs something down there or it will rust if you ride in the wet. I think the orignal poster has an al bike he did not say, but I've seen rust on al also.....


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## spookyload (Jan 30, 2004)

Tighten it till it makes a sound similar to stepping on a box of captain crunch! Seriously, it doesn't have to be white knuckle tight. Like someone else suggested, if you can force the seat to move with your hands, then it is too loose. I always mark a tiny spot on the post to make sure it isn't creeping into the frame and also to give me a reference for seat height if I need to take it out and reinstall it for some reason. CF seatposts are pretty strong to crushing force as long as it is symetrical force. If the clamp is removable, most companies recommend rotating the bolt to the opposite side as the split in the seattube.


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## ringroadwarrior (Dec 8, 2002)

*Is Al.*

My frame is Al. Instructions do give a torque setting of 12lbs. Says nothing about reversing the collar.Would this be a good idea anyway?


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## spookyload (Jan 30, 2004)

I just installed a new USE alien, and it said it very specifically in the instructions to do that. I don't know if it is true for all, but it can't hurt. They said it provides less crushing force.


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## jaldridge (Feb 27, 2005)

ringroadwarrior said:


> My frame is Al. Instructions do give a torque setting of 12lbs. Says nothing about reversing the collar.Would this be a good idea anyway?


12 lbs isn't a torque, it's a force. 

If you mean 12 inch-pounds (a pound of force applied to a foot-long wrench), then that sounds pretty light in the way of torque. It seems like 40-50 inch-pounds would be about right. I think the advice to tighten to effect (no movement) is the best. 

I have a Trek Pilot 5.2 (all carbon), and I haven't had any problems.

Jim


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## wunlap togo (Oct 1, 2004)

johnny99 said:


> The reason to grease is to prevent a metal post from reacting with metal in your frame. A carbon post does not have this problem and should not be greased. Follow the torque recommendation for the post. If it slips, tighten 1/4 turn at a time until it doesn't slip any more.


Carbon posts most certainly can react with the metal of a frame and become badly stuck. I have seen it happen with several steel frames including my own. No grease- post can get stuck. Grease- post can slip. I think some manufacturers are concerned that certain kinds of grease can affect the carbon and weaken it although I'm not sure where I heard that. Get an aluminum post and use grease.


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## Spunout (Aug 12, 2002)

Or use a silicone lubricant between carbon and aluminum, not petroleum.

I tighten my Chorus carbon (with proper clamp) tight enough so that I can't twist the saddle. Probably less than 10Nm, just about two fingers tight.


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## clintb (Apr 8, 2002)

On my TCR Composite, Giant reccomends 60 in-lbs. Before that I had a TCR Zero Al and they reccomended 120 in-lbs, which seems a bit high.


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## cdmc (Feb 3, 2004)

I just torque down until I hear the post crack, pull it out, put a new post in and don't tighten quite as much.      

I couldn't help it.


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