Dec 11 2008
Stuck Seatpost 201
On Wed, Dec 10, 2008, Adam wrote:
Hey Erik,My name is Adam, I took part in your Fall bike maintenance course at Bowdoin college this year. I know you said we could email you if we had any questions after the course, and I have seemed to come into quite a predicament with my own bike. About a week ago I was cleaning my bike, when I decided to take my seat post out. I got it pretty far out, until it got stuck completely. It was really too high to ride so today I took it to the L.L. Bean bike service shop (Center Street was closed). Well, LL Bean has tried and tried, they sprayed some kind of lubricant around the edge of where the seat post enters the frame, they have heated it up, used vice grips and even clamped the seat post and put all their body weight on the frame trying to get it to budge. They called me up saying that their final resort is really banging on the frame and their is a possible chance of cracking the frame (they wanted my go ahead, before doing so).
Essentially my question is should I let them do it, or are their other less detrimental solutions. I talked to my brother who lived in this area for a bit, and he said that their is a bike shop in Bath that is the best around. He suggested taking it their. He also said that their might be a possibility of cutting the seat post out. I had a hard time imagining this, but perhaps that is a solution.
Pretty much I am looking for any advice. I don’t have money for a new bike, and would really enjoy to continue riding my current one.
Thank you very much in advance, and I look forward to your response.
Sincerely,
Adam
Hi Adam,
Glad you wrote to me about this. I’ll see if I can help.
Welcome to Stuck Seatpost 201! The shop already did 101 so this is an upper level course.
To start, let me just say that the weird part for me is that you said you could get it to come out some yourself, then it got stuck. Does this mean it pulled out to a certain point and then froze? How hard was it for you to get it out to that point? Whatever your answer, it’s a good sign that you got it to move at all. So the next questions are how much is out and how much is in and do you care about saving the seat post and how much damage is done to the post already. If the other shop put vice grips on it and still haven’t had any luck, it’s probably pretty ugly at this point. I’d suggest you write off the post. Consider it collateral damage. But it’s got to come out, so here are some ideas.
First, ask the shop to stop before they bang on the frame. That just sounds ugly. It sounds like they’ve tried the usual methods with no luck so trying another shop could be good for your bikes sake. If shop/mechanic #1 is now frustrated with it and ready to bang on it, they may show it less love than a fresh set of eyes. The shop in Bath is Bath Cycle and Ski and they are excellent. You may also try Center Street Cycles again, if you can work around their winter hours. So keep them both in mind. Not that the LL Bean shop is not good, but the idea of banging on it doesn’t sound overly productive. The fact that they called you first speaks well of them, but also indicates that they are running out of ideas. Also, they probably mean that they are going to bang on the post. Sometimes it works to try to push the post back into the frame. If it moves at all and is covered in lubricant, it may get the lube into where you need it and do the trick. Or not.
Here are some methods that you could try or suggest to a shop to try:
Before you do too much more, take off your wheels and the seat so it’s easier to toss this thing around.
1. If they heated it up, they hopefully just heated your post, not the frame, since they probably used a propane torch. That could work but it’s rare. If you heat the post, it expands and is then stuck more. The hope though is that it will cool and shrink and that expansion/contraction is enough to break it free. I’ve not had great luck with this method. Heating the frame would help get it out but could damage the frame or at least toast your paint job if they use a torch. You might try getting a few gallons of water pretty hot, nearly boiling and pouring it on your frame, at the seat post, so it gets the frame hot but doesn’t touch the post. This will heat your frame up which will make it expand and may release the post enough that you can pull it out. To do this, read on.
2. To pull it out, I would suggest you take off your seat and clamp the seatpost in a vice right where they seat post meets the clamp at the top. The clamp usually is inserted into the post about 2 inches and you want to clamp it just below where the the post and the seat clamp meet, so that you can tighten the vice and not just crush the tube of the seat post. The vice itself needs to be secure and if you are considering the method I described above, it may need to be outside. Pouring gallons of hot water on the floor in the shop basicly rules this out for most shops. I’m pretty sure the BOC has a vice and you could bolt it to a piece of plywood like the one I brought to class, then clamp that to a table or a truck bed outside. You’ll need to get creative with this but if you are going to pour hot water on it, it’ will be messy so you’ll need to do something. I know you guys have boat trailers, maybe clamp it to one of them. (What would be great is one of those telephone company trucks with a vice mounted on it’s bumper!) So get a buddy or two, clamp it in with the bike hanging out to the side. Then have one of you pour the water while one of you slowly tries to twist the bike while pulling on it, to try to get the post to move. Turn around and see what you will land on if it pulls right out, before you start pulling. Slow steady pressure this way is unlikely to really damage your bike and you can use the frame for leverage. If you feel like you are about to bend your frame, stop. You need another plan.
Now if that doesn’t work….
Plan B is a long version of what you just did. Take off your water bottle cage if you have one on the seat tube of the frame. If you don’t, take out your bottom bracket and turn the bike upside down. Spray your lubricant of choice in the seat tube from the water bottle cage mounting hole or the bottom bracket and wait. I’d suggest you try Liquid Wrench. Spray some in and wait a few hours then do it again. Do this now and then for a few days, then put it back in the vice like above and see if it will come out. You can also use Pepsi but I suspect the shop already has some lube in there and that may negate the ability of the Pepsi to actually touch the metal. I”m not sure on that.
Plan C is to do the Liquid Wrench and the hot water trick together.
Plan D is to cut off the seatpost about 1″ above the frame and then try to slice it down the middle like your brother suggested. This makes me cringe just writing it. Plan on a tedious job. I’ve spent a lot of time on this method. On the plus side, it’s always worked. Here is how:
Cut off the post leaving 1″ sticking out of the frame. Measure how much of your seatpost is in there. Lets say you have 6″ stuck. Now get a hacksaw blade that is about 12″ long. Wrap the end of it with a rag to make a handle so it has about 9″ of blade exposed. Hold the rag handle and start to cut the seatpost from the inside of the tube toward your frame. The post is usually aluminum so you will eventually cut through it. Cutting your frame will feel and sound different because it’s much harder so it’s unlikely that you will damage your frame. Stick with one groove that you are cutting. It will seem like you are not doing anything because you have hardly any leverage, but you will eventually make progress. Experiment with different coarseness blades and see what works best. Be patient. It take a long time. Eventually you will cut your seatpost from end to end, down one side of the post, all the way to your frame. This may be enough. You can now try to take pliers and squeeze the top of the post together ever so slightly. You have about a 1/16″ cut from the saw to work with. While you do this, spray some more Liquid Wrench where it is pulling away from the frame. You want to get the lube between the post and the frame. Work both sides of the cut in the post, pulling it back and spraying in the lube. Be gentle with the post because you don’t have much to pull on. Try pulling it out too as you do this and see if it moves. Try spraying it, and and waiting. Try wiggling it. Try talking to it. If it still wont, cut a second grove about 1/4′ away from the first one. When you are done, you can peel back the sliver of post that is between the two groves. Now you can defiantly collapse the post in on itself, spray in lube and pull that sucker out.
If you want to get some other ideas, check out Sheldon Brown’s site. He’s wicked smart!
Go get a beer. You’ve just completed this class.
Now all that’s left to do is clean up the mess. And part of that is to clean up the frame. You have aluminum shavings down in there and they will get your next post stuck if you leave them in. So i’d suggest compressed air if you have it or go to a carwash and spray the car wash wand in there to wash it out. USE EYE PROTECTION either way since shavings will be flying out of there. Be sure you remove your bottom bracket before you do this so you don’t wash all the lube out of that and find it stuck in the frame in 3 months! Then I would suggest you get a shop to run a deburring tool down in there before you put in another post. It is a round brush-like tool called a Flex-Hone that goes on a drill and has little sanding blobs on the end of the bristles. It kind of reminds me of a tiny chimney sweeper. If you put any burrs in the frame inside as part of getting this out, it will smooth them off. Also, your frame probably has corrosion in it, which is why this got stuck in the first place and it will remove that. You can buy one and use a drill but you may never need it again so paying a shop may be more cost effective.
When you do finally put in your next post, it should slide in smoothly. If it does, you’ll know you did a good job. Then, be sure to grease both the post and the frame and pull the post out every few months and make sure it still moves, clean it off and regrease it. That way you will never have to do this again!
So as you can imagine, having a shop do any of this will cost a bunch of money because it’s so potentially time consuming. So you might want to do it yourself, at least in part.
Best of luck with it and please let me know what you decide to do and how you make out.
Erik West
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