seatpost slipping: suggestions?

[Climb01742]

so here's my situation: aluminum post in a steel frame. and it's slipping.

originally it was just post in frame. after having it slip considerably, i applied grease inside the top of the seat tube. this mitigated the slippage but it still loses a few mm's each ride.

any suggestions for further fixes to keep the alu post from slipping?

one option, adam hansen uses a second seat collar. thoughts?

http://www.cyclingnews.com/features/...lium-sl/297688

another option is to try another post. but it's a 31.6 post and only other one i have is carbon. if i try the carbon, i assume i should clean out the grease from the seat tube and apply carbon paste? any downside to residual grease mixing with carbon paste?

to sum up my situation in a word: help!

thanks!

[oldpotatoe]

Originally Posted by Climb01742

so here's my situation: aluminum post in a steel frame. and it's slipping.

originally it was just post in frame. after having it slip considerably, i applied grease inside the top of the seat tube. this mitigated the slippage but it still loses a few mm's each ride.

any suggestions for further fixes to keep the alu post from slipping?

one option, adam hansen uses a second seat collar. thoughts?

http://www.cyclingnews.com/features/...lium-sl/297688

another option is to try another post. but it's a 31.6 post and only other one i have is carbon. if i try the carbon, i assume i should clean out the grease from the seat tube and apply carbon paste? any downside to residual grease mixing with carbon paste?

to sum up my situation in a word: help!

thanks!

Good bike shop will have a knurling tool...makes ridges in post, no slip no mas.

[Ken C]

I had the same problem with a cheap steel commuter frame a Pake C'Mute.

I use carbon paste on an aluminum post and now it does not slip without having to result in excessive torque on the binder bolt.

[Grant McLean]

The very smooth and polished Easton Dura-Ace post used to slip in my Kirk,
and i put some of the Finish Line fiber grip on it, which seems to have solved
the problem.

http://www.finishlineusa.com/product...ts/fiber-grip-

-g

[Ken C]

Originally Posted by Grant McLean

The very smooth and polished Easton Dura-Ace post used to slip in my Kirk,
and i put some of the Finish Line fiber grip on it, which seems to have solved
the problem.

http://www.finishlineusa.com/product...ts/fiber-grip-

-g

That is the same stuff I use.

[vqdriver]

Doesn't have to be carbon to use carbon paste.

[shovelhd]

Originally Posted by Ken C

That is the same stuff I use.

Me too. Cheap and effective.

[Tony T]

I had this problem and it was the fastening nut that was not staying tight (5nm).
A little loc-tite on the threads solved it.

[Peter P.]

Make sure the clamp bolt is not bottoming out at the coincidental torque to give you SOME clamping force but not ENOUGH.

I've read that grease on carbon posts does something bad like penetrate the epoxy, making the post slip even more and after that, difficult to remove the grease's effect.

Measure your 31.6 post to verify it's not undersized.

According to my Sutherland's manual, the seat tube for your particular mating of steel frame to aluminum post, the seat TUBE can be as large as 31.8mm and still work with your post. Ideally, the seat TUBE would be no larger than 31.65mm.

You could have the "perfect storm" of an oversized seat tube AND undersized seat post.

My only concern with using carbon past is, will it prevent rust in the seat tube and impair seizing of the seat post.

[shovelhd]

Originally Posted by Peter P.

My only concern with using carbon past is, will it prevent rust in the seat tube and impair seizing of the seat post.

That's what it is designed to do. It's just grease with grit in it.

[Dead Man]

I had this problem.... I finally realized my seatpost clamp had a crack in it. I used my tail light clamp as a brace of sorts to try to get me the last 50 miles, but it finally broke all the way through and I had to low-rider it to a bike shop for a temp clamp. Fortunately, I was a few miles from a shop- 'cause I probably looked like an idiot

But I obviously rode around with it cracked for some time- I hadn't had any problems, then one day I noticed it had slipped and from that point on I never could get it tight.

[bikingshearer]

Originally Posted by Ken C

I had the same problem with a cheap steel commuter frame a Pake C'Mute.

I use carbon paste on an aluminum post and now it does not slip without having to result in excessive torque on the binder bolt.

I had the same problem with my old (1967) Schwinn Paramount frame (now the baddest ass commuter ever). Carbon paste plus a very small soda can shim did the trick for me. I tried the shim first, and added the paste when the shim alone didn't quiiiiiite get it done.

With the benefit of hindsight, I'd say try the paste first. If that doesn't work, add the shim (and you'll be surprised by how narrow the shim will be, but using snips on a soda can is easy-peasy-lemon-squeasy). If that doesn't work, do Old Spud's knurling thing. If that doesn't work, get a different bike.

[Kontact]

Originally Posted by bikingshearer

I had the same problem with my old (1967) Schwinn Paramount frame (now the baddest ass commuter ever). Carbon paste plus a very small soda can shim did the trick for me. I tried the shim first, and added the paste when the shim alone didn't quiiiiiite get it done.

With the benefit of hindsight, I'd say try the paste first. If that doesn't work, add the shim (and you'll be surprised by how narrow the shim will be, but using snips on a soda can is easy-peasy-lemon-squeasy). If that doesn't work, do Old Spud's knurling thing. If that doesn't work, get a different bike.

I can't speak for 1967, but many later Paramounts used 27.4 seat posts.

[bikingshearer]

Originally Posted by Kontact

I can't speak for 1967, but many later Paramounts used 27.4 seat posts.

Good thought, and I tried a 27.4 - no chance. I even found and tried a 27.3 - again, no chance, at least not without an unacceptable amount of grinding. So I was left with paste-plus-shim. Not exactly the most elegant solution, but it's working.

I think 27.4's didn't come in for at least another 10 years, maybe more, but I'm not certain. I do know that any Paramount I have seen and could check from the late 60s to mid 70s had a 27.2 post.

[RobJ]

Another cheap, simple solution is a piece of tape wrapped around the post at the position where it would meet the top of the seat tube. Some type of tape that has a cloth/fabric backing.