chrispe

I know there are a ton of threads on stuck seatposts and I know seatposts can be a pain in the ass a lot of the time, but I actually feel this case is out of the ordinary. I've tried everything on Sheldon Browns website and basically everything I could find on here. I broke a bench vice, a hard plastic saddle, and several other things with brute force trying to get it out. I tried soaking it in ammonia, penetrating oil, and rust removers. I basically tried anything I could find so it finally came to the point where I decided to break out the hacksaw. After sawing the post off about half an inch above the frame I found, much to my surprise, that the inside of the SR Laprade seatpost is narrower than a normal hacksaw . So now I feel as though I've come to a point where it may be hopeless, but I thought I should ask if anyone has any ideas. So far my only ideas are:

1. Drill a larger hole in the middle of the seatpost. This would be the obvious choice if I already had huge drill bits, but they seem to be very expensive, and while I don't mind spending time on this I would prefer not spending money especially since I will probably only use this bit once and while I like the frame (Trek 613 so basically 610 frame) its not worth all that much considering its not in great condition.

2. Dissolve the seatpost in something and hope it doesn't eat the frame. I know oxalic acid shouldn't harm the steel to much and should do something to the aluminum, but I don't know if it will eat away at the aluminum enough. I know lye would most likely dissolve the post, but I don't know what it would do to the frame.

3. Trash it. I hate to do this, but it seems to be becoming more and more of an option.

Any help or suggestions of other routes would be greatly appreciated.

Schnayke

I would say maybe get ahold of a grinding bit and just make a slot big enuf to get the hack saw in, and then finish the job. I don't think a drill big will work but a grinding bit will.

Last time I had a seat post stuck I used a heat gun and a welding bench vise to get the post out. You really should have killed the frame before the vise broke. If it was in one piece still, I would say find a better vise. But for real the vise is the way to go, you just run the risk of killing the frame. I don't know what happend to your vise.

southpawboston

re: your ideas:

1) you could use a dremel grinding bit to create a channel in the seatpost, which may allow you to get the saw blade in there. the hole might get wider toward the bottom of the seatpost, so if you create a small channel near the top, you may be in luck. not sure about the laprade in terms of a tapering hole. i can check on one of mine and post back. alternatively, can you find a narrower hacksaw blade for not a lot of money?

2) there's nothing that will dissolve the aluminum without seriously hurting the rest of the frame. oxalic will oxidize the surface of the aluminum, but not dissolve it.

3) be patient. don't trash it just yet.

additionally, i've heard some people report great success with an aerosol spray that freezes the metal. the aluminum contracts faster/more than steel, and that may free it up.

takingcontrol

I have no Idea if this will work but it may be worth a shot. Get some electric pipe wrap ( the wrap you plug in to keep pipes from freezing). Place the frame in an salt and ice water bath (should get the frame down to approx 17 °F ) once frame is cool wrap the seat-tube with pipe wrap. Hope the thermal difference will allow separation.

ilikebikes

Wow! I sure was lucky!

chrispe

I should clarify with the vise it was a cheap vice and what broke was the bolts which you could loosen in order to turn the vice to a different angle so now if you try to put pressure on it it will swivel around, but unfortunately that's the only vice I have access to. I forgot to mention I tried heating it with a torch even though I know the aluminum expands faster and that did nothing. I also tried spraying it with canned air which cooled it down slightly, but not very much and I think I would need to use something else for it to be effective at all. I don't really know a better way of cooling it though. Also it is much more difficult to get a grip on now that it is cut. I tried something similar to south paw's suggestion for #1 which was to cut a slot all the way down to the frame with the hacksaw. I tried to get the blade in at an angle, but it still did not work at all. Also I just measure the inside hole of the seatpost and it is about 11.4mm in diameter. I'm not sure if they make thinner hacksaw blades and I assumed they were all pretty standard, but its worth checking.
Thank you.

curbtender

You may be able to use a jig saw blade. Cut two sides down then colapse them with a punch.

cudak888 

I had a stuck handlebar stem recently in a Raleigh Gran Sport fork. Wouldn't come out for anything.

I tried that "highly praised" Freeze-Off too. Nada. Not impressed.

-Kurt

auchencrow

If it has annealed itself to the inside of the tube there is a chance that it will never let loose, even if you do the whole hacksaw trip.

(I had a similar problem on a Miyate 710 and after trying all of Sheldon's recipes, and breaking a vise , freezing the post, heating the tube with a torch, failing the post torsionally, and cutting no less than three full depth slots with a hacksaw I was left with three segments still permanently welded onto the tube.
(It was also a LaPrade post and I had to start the cut with a cut down hacksaw blade because like yours the inside diameter was initially too small).

If I had it to do over again, I'd FILL that seat tube with PB Blaster,( through the BB opening or bottle cage mounts), rap it a few times with a hammer, then hang it upside down from my garage rafters for a year or so.
- That's because in most situations I've encountered since, there is nothing I've found more effective than PB Blaster and patience.

BillB.

Try the old torch approach! The right amount of heat will losen that sucker!!!!

unworthy1

lye will dissolve the aluminum, but won't harm anything ferrous (steel). It can harm brazing and paint, so if it was me, I'd mount the frame in a solid stand upside down and over a bucket...inject the lye solution thru the open BB into the seat tube with a turkey baster or a long funnel, make sure you don't spill a drop, wear gloves and safety glasses, allow for ventilation.

r0ckh0und 

I just drilled out a stem yesterday. I was fortunate enough to have a drill and bits at my disposal. Things got very hot while drilling..........need to cool it with oil when drilling. You might also try and find a bi-metal sawzall blade, some of the cheaper ones may be a little narrower than a hacksaw blade.

Another thought is to drill a series of holes with a smaller diameter bit to create a slot for your hacksaw blade.

JohnDThompson 

If this is a steel frame, and you don't mind ruining the paint, you can melt the aluminum post out with a propane torch well before the steel gets harmed. Clamp the frame in a stand upside down over a bucket of water. Heat the seat tube where the post is stuck with the torch. Eventually the aluminum will melt and drop into the water. It tends to go from solid to liquid almost instantaneously when it's hot enough, so it's important to have the bucket positioned to catch the molten blob of aluminum. Otherwise you could get burned or start a fire. Or both.

raverson

The worst stuck seat post I've ever dealt with was on an early 90's Schwinn High Sierra MTB. I tried PB Blaster, heating the post, twisting in a vise, and would have tried hacksawing but didn't because of the length of the post. What finally worked was removing the BB and drilling a hole from the bottom of the shell, lining up with the seat tube. I then inserted a steel 1/4 inch rod long enough to reach the post and drove it out by pounding. Worked like a champ and now the BB shell has great drainage.

merlin55

avoid the torch route, also beating on the poor frame, assuming you don't want to trash the frame. Your best bet. is to take a new hacksaw blade, and use a bench grinder to make the blade narrow so that it will fit into the chopped off seatpost. Saw 2 slots, opposite each other, very carefully to not cut the steel seat tube then carefully use a screwdriver in the cut slot to loosen the seatpost pieces....relax, take your time and think positive

auchencrow

Now THAT is a novel idea !

wrk101

+1 That's the ticket.

As far as using lye to dissolve the post, it will also ruin your paint.

I have a Trek 500 to cut out the seat post right now myself.

chrispe

Thanks everyone I think grinding down the blade will be my first choice now. Once i got the top off I was very frustrated to find that I couldn't get the blade in the hole and could not think of an immediate way to thin the blade or buy a thinner one. I'm surprised at how thick they made these seat posts even considering that they are fluted. I was also considering the lye down the seat tube, but think its probably best to avoid dangerous chemicals. I actually don't have a bench grinder and didn't think of that, but I have access to one at my schools community bike shop so that should do the trick.

soonerbills

I have found hammering a severely stuck post slightly down further into the tube works to break them free. I then use a pipe wrench to twist them out. Of course all this with the help of a lubricant.
Now that you have cut off the post the above method using modified hack saw blades and a punch or chisel probably be your only choice. Good luck!

Steve530

Since the hole is about 11.4mm and the seatpost is probably about 27mm, the seatpost is probably about 7mm or 8mm thick. That's pretty thick so maybe you could drill a small hole vertically in the seat post to get the clearance for a hack saw blade. Maybe start with a 1/8" bit and go up to a 1/4" bit a little toward the center.

auchencrow

"...Saw 2 slots, opposite each other, very carefully to not cut the steel seat tube then carefully use a screwdriver in the cut slot to loosen the seatpost pieces...."

Certainly this is is a good method, but just be advised it does not work in all cases when the aluminum is chemically welded to the steel through galvanic action.

illwafer

i would try to find a blade that fits down the tube.

dedhed

I've narrowed hacksaw blades with a good pair of tin snips. Way less work than grinding.

unterhausen

mount the bike in the toolpost of your lathe. Use a 1" drill bit in the head, and it will probably pull out. If that doesn't work, remove the remnants with a boring head. You do have a lathe, correct?

jmichaeldesign

I ran into the same situation with a stuck stem. Being that the aluminum was so thick I was able to drill 4 holes in just the wall of the aluminum stem after cutting it flush with the fork. I then slowly stepped up the size of the drill bits until I was actually cutting all the way through the aluminum. I then used a punch the collapse the 4 pieces and it all came out. The inside of the steerer was a bit marred but still completely functional.