DaveLeeNC

I have a nice, but older (mid 90's) EL/OS steel frame bike. The (carbon) seatpost is, apparently, seized to the tube. I have used some WD40 (not the best of penetrating oils for sure), heavy twisting of the saddle, and spreading the tube clamps with a screwdriver. No luck so far. All I really want to do here is to point the nose of the saddle just slightly more to the right. At this point it is (arguably) pointed just slightly left (not by much) and I am getting chafing and irritation on just the left side..

The seatpost has been in for about 4 years (and never moved that I know of - but my LBS does most of my work). I don't ride much in the rain but it certainly happens on occasion.

From all I know my options here are

1) A better penetrating oil (and possibly let it soak upside down in a pool of it by turning the bike upside down and pouring a bunch into a bottle holder hole)

2) Use of heat and/or cold to take advantage of the different coefficients of expansion of steel vs. carbon. Cycling between the two might break it loose, and just heat should (in theory) expand the clamp but not the carbon seatpost.

3) Remove the seat and use something else (not sure what) that would allow more torque to be applied. I am not sure how much force can be applied before the carbon seatpost is toast

Other thoughts or ideas? Anything more complicated than those above and (me not being a mechanical type) it is probably a trip to my LBS.

Thanks.

dave

RoCou

The classical method is to remove the seat, clamp the top of the seat post in a bench-mounted vise, and turn the frame - allowing a much longer lever than other methods. But with a carbon post, the probability of breakage is high. Heating the frame could help (steel will dilate, carbon not so much). Depending on the value of the seat post, I'd try the vise method, accepting the probability of breakage (which would be followed by Dremelling the remnants of the post out of the frame).

The vise method worked for me with an aluminum post into a steel frame.

mrt2you

try a heat gun on the steel tube.

Brocephus

I think you're already on the right track here. Get some real penetrating oil, and try the hot-cold thing (while being careful not to go too extreme on the temps). Just don't get impatient and break the post, causing even more grief.
I would exhaust these options before wasting the money and letting the LBS chimps take a swing (and probably try basically the same things. I don't think they have a special, double-secret, $500 Park Tool made just for this application ! )

shelbyfv

Yes, turn it upside down and get some liquid penetrant in the seat tube. PB Blaster, Liquid Wrench, etc. It may take a few days. Tap around the post and tube occasionally to keep it moving. Don't use more force on the post, you've been lucky so far. You may want to research whether the post is still safe to use after the chemicals.

DaveLeeNC

Thanks for the comments.

I do have a heat gun (from back in my golf club building days), so I really do need to try that one. Anybody have any idea at what temperature a carbon seatpost begins to change dramatically? The epoxy used to bond shaft to hosel breaks down around 300 degrees F, and that does NOT hurt a carbon fiber golf shaft.

The one thing that my LBS probably does have (that I do not) is a good vise clamp for use on a seatpost.

dave

DaveLeeNC

You may be right about 'hidden breakage' of the seatpost (for lack of a better term). However, in a good amount of reading at various sources I have not seen that being reported.

Thanks for the input.

dave

shelbyfv

That would be the last thing you'd want to use on a carbon post. Once you've soaked it, try tapping vertically, up and down, rather than twisting.

Mad Honk 

Dave,
If you watched my "Naked Dave" series on the ICG* website you will note that I posted the breakdown temperatures for both epoxy and carbon fiber in one of them. Carbon fiber will break down at 350* in most cases and the epoxies will break down between 275* and 300*. There is a fine line before destroying the carbon fiber. Most of the posts here have advised to use a lubricant to loosen the seat post. The lubricants will break into the carbon fiber and create a swelling of the tubes and lock the seat post into place even farther. A better solution would be to use hydraulic pressure like you did when removing golf heads from the CF shafts. It will take a bit of designing work to make a jig that will put a small hydraulic jack in between the BB and the seat post base, but it is the safest way to remove the post. Smiles, MH

* International Clubmakers Guild (I was one of the principals in the making of the "guild")

DaveLeeNC

WOW - thanks for the info. When pulling a golf shaft you were always kind of protected by the constant pressure showing you pretty much instantly when you had broken the epoxy bond holding the clubhead. I was just a hobbiest type club builder but never I ruined a carbon fiber shaft. However this is different. I guess that boiling water is the only safe solution here.

I do not have a hydraulic shaft puller but do have a decent quality mechanical one that did the job for me. Where the seatpost slides into the seat tube is a whole lot like a golf shaft and clubhead hosel (sizes are different of course). Interesting thought. Thanks.

I don't recall the videos, but I do remember you being a most valuable contributor on one of the club building forums a while back. GEA maybe? Or maybe the Wishon forum when Tom was still active? I have been out of that as a hobby for quite some time.

dave

Mad Honk 

Dave,
That was a few years ago, but I taught at PCS as a Master Professional, and was active on Tom's website. I did a lot of teaching at ICG through the web with help from guys like Don Johnson. We were inducted into HOF I think in 2014. I am still active in the AGCP, with an anticipated "masters" from them this year. Jim and his wife Mikey helped me create the Naked Dave series of instructional videos. A lot of great memories from back then....
The process you are doing though is just like pulling a head from the shaft. There is no epoxy bond but a brinneling of the steel against the carbon fiber,which can be as strong as epoxy. Vertical pressure just like a golf shaft is the best, with a light heat applied to the seat tube, and not the post. When it comes out, treat it like a shaft tip and clean it with a light sandpaper before re-installing it. HTH, MH

DaveLeeNC

Two things are for sure here

1) This has got to be fixed. Somehow my saddle nose is pointed maybe 1/16" to the left (you really have to line it up to see it). But I have ramped up my mileage and am having lots of chaffing on the left side only. I have to believe this is the culprit. Chamois butter/etc is helpful, but not enough.

2) This thing is unlikely to come out in one piece (a pretty high end Bontrager XXX, unfortunately). I am not even sure at this point if penetrating oil is going to be helpful or actually make the problem worse.

So I am going to talk to my LBS to get their opinion (small shop and I will be talking to the guy who would do the work). If I don't hear anything unexpected, I'll probably just take the heat gun and a bunch of torque. And if it goes like I expect (unsuccessfully) I will probably end up heating (steel frame) the collar until I can basically spoon out the old seatpost.

Not sure what else to do here. I just don't have the tools and skills to make a proper jig, although I could probably design one.

Thanks for the input.

dave

Mad Honk 

David,
You have the skills to remove this seat post. And the desire to do so. The jig may be a bit difficult to create, but remember that you are paving the way for many after you who will experience the same thing. This is what will determine your place in the cycling world of mechanics. Find a way to make the jig and then post it here. Same way I did it a the PCS, ICG, AGCP. You're a smart fella! Give some of your expertise back to this group of new mechanics. Smiles, MH

Gresp15C

About the heat gun, I haven't messed with carbon bike parts, but I sometimes have to disassemble small optical assemblies at my workplace. I've found that for virtually any epoxy, 1 minute with a heat gun breaks the bond. And the adhesive does not recover when it cools.

DaveLeeNC

Unfortunately there is a schedule problem here. Despite my better judgment I have decided to ride the Six Gap Century (over 2 miles of climbing) for my 70th birthday this year (the ride is the end of Sept). The chafing is becoming a real training problem and there just is no time for me to muck around forever on this.

So off to my LBS today.

dave

conspiratemus1

This has been a most informative thread. Do hope to hear how it works/comes out. Certainly agree that small adjustments in the yaw of a seat post can make all the difference....and perfectly centred is not always the best for one's own anatomy.

DaveLeeNC

Well, this has been f***king frustrating. My LBS (I am dealing directly with the owner who is also the guy doing to work) has managed to move it about an inch so far. He is using some kind of penetrating oil, and he is finding that helps (it may not be exactly penetrating oil - I got the feeling that it was something else). But if I understand what he told me when he moves it a little it kind of re-seizes, so you start again. He doubts that this thing is coming out in reusable form (kind of what I expected).

I asked about melting it and kind of spooning it out and he would be concerned about the integrity of the frame paint in that case. And destructively removing it in any other way is going to be hard at best. He is going to talk to a couple of frame builder guys that he knows well for guidance here.

So here I am trying to train for the Six Gap Century without a bike! Like I said, the has been frustrating.

dave

ps. Here is a pic taken prior to replacing the stock handlebars.

shelbyfv

Nice bike! That carbon seatpost can't have been happy on classic steel. It's now getting revenge, even to the death. Choose a polished silver one next time, match the stem

RoCou

Taking it out in destructive mode is easy - cut it above the frame, and Dremel multiple grooves straight down the inside of the post.

le mans

Nice bike

I never heard of carbon seat post seize in a steel frame before. aluminum or carbon ..yes.

What sort of penetrating oil was he using?


BTW judging by my fiberglass experience i'm sure carbon would burn like fiberglass not melt like plastic

DaveLeeNC

I don't know what he was using.

The epoxy (as I understand things) breaks down at around 400 degrees (F, I assume). If you could get it to that temp without affecting the finish in the seatpost, it would come out I would think.

I was quite surprised at how all this has come out (pun intended).

dave

trailangel

Only one bike? Shame

DaveLeeNC

See https://www.bikeforums.net/road-cycl...ther-bike.html

:-)

dave

le mans

I'd settle for one classic italian, i'd fit a D curve handle bar on it though, a nice wide one to suit my broad shoulders


(nah, i'd have to have an internal gear hub cruiser too)

Carbonfiberboy 

AeroKroil is the good stuff, probably what your guy is using. The usual thing is to cut the post off about an inch proud, then kerf the remaining post in the seattube with a hacksaw blade in a holder designed for that use. Heating the seat tube is the usual thing before doing the former. Carbon posts should be installed using carbon assembly paste.