Bicycle Mechanics - Seatpost Torque

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View Full Version : Seatpost Torque


ivan_yulaev
10-31-05, 10:37 PM
So, how much torque on that seatpost? Mine has a bolt, not a collar-clamp.

It seems to be sliding down with the amount of torque I give it (10 ft-lbs?) I gave it about 25 today...we'll see how she does.


MudPie
10-31-05, 10:49 PM
So, how much torque on that seatpost? Mine has a bolt, not a collar-clamp.



Park Tool offers torque recommendation for bicycle fasteners: http://www.parktool.com/repair/readhowto.asp?id=88

ivan_yulaev
10-31-05, 10:58 PM
Yeah, for seatposts, they say "Minimal torque. Avoid overtightening." Useful, huh? :p


RockyMtnMerlin
11-01-05, 09:22 AM
So, how much torque on that seatpost? Mine has a bolt, not a collar-clamp.

It seems to be sliding down with the amount of torque I give it (10 ft-lbs?) I gave it about 25 today...we'll see how she does.
You did not say what type of seat post you have. If there is a manufacturer's website check that. The better seatposts normally suggest a torque range or a starting point. My Alien says snug it down minimally, mark where the seat post meets the seat tube and then go for a short ride. If it has slipped down, move it back up to the mark, tighten it a bit more and repeat until it does not slip. And remember if you have a carbon seat post - do not grease it!!!!!!!!

sydney
11-01-05, 09:26 AM
Yeah, for seatposts, they say "Minimal torque. Avoid overtightening." Useful, huh? :pIt's kind of a no brainer.There are so many fasterner types and clamping arrangements that a generalization would be worthless.Tight enough not to slip,but not so tight as to break the bolt or bugger a CF post. I find a small beer can shim keeps mine from slipping without getting too horsey with the bolt.

neil0502
11-01-05, 10:48 AM
It's kind of a no brainer.There are so many fasterner types and clamping arrangements that a generalization would be worthless.

The generalization I've heard (and I think it came from the Unsinkable Sheldon Brown) was: tighten it enough that you cannot rotate the saddle with the force of one hand.

RockyMtnMerlin
11-01-05, 11:01 AM
The generalization I've heard (and I think it came from the Unsinkable Sheldon Brown) was: tighten it enough that you cannot rotate the saddle with the force of one hand.
If you have a carbon post and you do this test, make sure that you have removed any burrs or rough spots from the inside of the top of the seat tube so that it does not scratch (and possibly weaken) the seat post.

neil0502
11-01-05, 11:47 AM
If you have a carbon post and you do this test, make sure that you have removed any burrs or rough spots from the inside of the top of the seat tube so that it does not scratch (and possibly weaken) the seat post.

Good point.

To add to that: with a carbon post, you should never insert or remove the post via twisting motion. Instead, remove/insert it with straight vertical pull or push. Avoids using your frame as a pipe cutter, scoring a cut in the seatpost that could weaken it over time.

MudPie
11-01-05, 09:13 PM
Yeah, for seatposts, they say "Minimal torque. Avoid overtightening." Useful, huh? :p

As they say, you get what you pay for! I didn't look at the table - sorry about that; I do keep it bookmarked and use the torque values as a guide.