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Seatpost torque/ carbon paste

Old 02-10-15, 09:58 PM
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Seatpost torque/ carbon paste

Hi all. I have a friend with a S2 who I ride with and the carbon post/ frame torque is 6-7 NM (I think). I was just wondering if you buy a torque wrench/ carbon paste to tighten in case of slippage, which ones do you recommend that can be bought on amazon? I never quite used a torque wrench before, usually just resorting to an Allen key to hand-tight. I know in carbon to carbon contacts you don't use grease, but carbon paste, so is there any specific paste that you guys recommend that is in a reasonable amount/ price? Thanks. I'd like to get both off Amazon to buy something else I need in a bundle.
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Old 02-10-15, 10:36 PM
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I'm too old school to talk torque wrenches. My rule is simple -- you have to tighten the clamp bolt tight enough to do the job, hold the post from slipping or twisting in use, and no tighter. So I approach it by degrees, testing by trying to twist the saddle. Carbon assembly paste provides traction, so the post holds with lower clamping force, which is always a good thing.

The paste comes in two basic types. Some have hard grit and provide super hold, as the grit bites into the post and frame. The drawback is that this scratches the post as you slide it in and align the saddle. The other type uses rubber like particles to grip without biting, and is preferable for this application, unless the grater grip strength is absolutely necessary.

BTW- for those who like to work by numbers, the question remains, what if you tighten to spec and the seat post still slips?
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Old 02-10-15, 10:41 PM
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I use a 3/8 ratchet and tighten the bolt tightly. I've used very tight on aluminum parts.
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Old 02-10-15, 11:04 PM
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Originally Posted by FBinNY
....The paste comes in two basic types. Some have hard grit and provide super hold, as the grit bites into the post and frame. The drawback is that this scratches the post as you slide it in and align the saddle. The other type uses rubber like particles to grip without biting, and is preferable for this application, unless the grater grip strength is absolutely necessary.....
Can you give examples of both types? Can you tell by the labeling?
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Old 02-10-15, 11:15 PM
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Originally Posted by Camilo
Can you give examples of both types? Can you tell by the labeling?
Offhand no, but I expect that if you visit the sites of the companies who offer them, you'll find descriptive information that might help.

I did quick serach for "no scratch carbon assembly paste" and came up with plenty on info. I'll leave the reading to you.
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Old 02-10-15, 11:19 PM
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Thanks. I have been using carbon assembly paste for a few years, but never knew there was a difference. I think I bought a tube of whatever my lbs had (there was only one among a 3 or 4 real bike shops in my town ... now they all carry it). The grit in the paste "feels" pretty hard, but I'm not sure. I'm going to find some scratch free stuff and compare.
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Old 02-11-15, 01:15 PM
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Originally Posted by FBinNY
I'm too old school to talk torque wrenches. My rule is simple -- you have to tighten the clamp bolt tight enough to do the job, hold the post from slipping or twisting in use, and no tighter. So I approach it by degrees, testing by trying to twist the saddle. Carbon assembly paste provides traction, so the post holds with lower clamping force, which is always a good thing.

The paste comes in two basic types. Some have hard grit and provide super hold, as the grit bites into the post and frame. The drawback is that this scratches the post as you slide it in and align the saddle. The other type uses rubber like particles to grip without biting, and is preferable for this application, unless the grater grip strength is absolutely necessary.

BTW- for those who like to work by numbers, the question remains, what if you tighten to spec and the seat post still slips?
FB, can you recommend a no scratch carbon paste that you use? You would just apply it to the carbon seatpost where it contacts the frame in a thin layer, right?

I found https://www.amazon.com/Tacx-LU2400-P-...FV1AG96B16SM9R
https://www.amazon.com/Park-Tool-Supe...0YW3RG62G2S9CW


I just mainly want a cheaper/ reasonable quantity since it will take forever to use up. I'm prefering the second one since it's cheaper but I can't really tell if it's the gritty or non scratch version.
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Old 02-11-15, 01:22 PM
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Originally Posted by Monkey D.Luffy
FB, can you recommend a no scratch carbon paste that you use? You would just apply it to the carbon seatpost where it contacts the frame in a thin layer, right? ....
First of all, I don't do brand recommendations. Secondly I don't own any carbon fiber bikes or posts. I use a copper based anti-seize that I voodooed with some ground peat moss years ago, before CF paste existed. For serious slippage issues, I use lapping compound. (which will scratch posts).

Finish line, Tacx, and others advertise fiber based no scratch carbon pastes. Odds are that may also scratch posts, just less. The key to limiting scratching is to know how deep you want to go, so you don't mar the exposed post, and to minimize twisting as you move the post to final position. In any case, do not force a semi tight post that has any kind of traction paste, since that will definitely scratch it.
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Old 02-12-15, 09:00 PM
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If the only task that frequently requires accurate torque limiting is tightening clamp bolts at the seatpost, stem, and handlebars, I'd check to see if they require similar torque values (maybe 1nm of variance). I'd then consider a torque key like: this at a value that does not exceed the value of any of the parts. These are inexpensive and easy to use. Otherwise, I have Amazon.com: Effetto Mariposa Giustaforza II 2-16 Pro Torque Wrench Red, One Size: Automotive , but that's probably nicer than you (or I) actually need. But some kind of low torque click torque wrench is good for these kinds of things.

I use Finish Line Fiber grip. It works fine; I have not used any competing products. It can also be useful for clamping aluminum handlebars, and to reduce the torque needed to secure threaded steerer wedges.

Last edited by cpach; 02-12-15 at 09:06 PM.
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