roccobike

A charity that I do some work for from time to time contacted me to see if I'd work on a vintage Trek for them. I picked up the bike today and it's a winner. A 1984 Trek 760 with Reynolds 531 Professional tubing. Just to make it interesting, its a 56cm, my size. First thing I did was to check the seat post and the stem. The seat post is tight, but turns. When I checked the stem, the problems started. The good news is the quill is loose. It separated easily with a mild tap on the shaft. The bad news is, the stem won't budge. I know others have run into this before. Knowing the quality of the frame we're dealing with, I'm not willing to chalk this one up to "too bad". The stem is a Cinelli and the headset is Campy. Obviously I'd like to save the stem, but if it has to be sacrificed, so be it.
I just hit it with PB Blaster and Liquid Wrench Penetrating oil both top and bottom and currently have the bike upside down to let the penetrating oil seep in. The Campy headset can be loosened to allow PB Blaster directly on to the stem where it goes into the steer tube. Before I try anything else, I'd like to know if anyone has come up with a method that's successful in loosening the galvanic action that's occurred.

bikemig 

Park has a good description of different ways of taking care of this

https://www.parktool.com/blog/repair...osts-and-stems

If the PB blaster and/or trying to cut it out doesn't work, then it gets really tough.

At that point, lye can be used but that can also be dangerous stuff to work with.

Here's a thread,

https://www.bikeforums.net/classic-v...r-way-out.html

wrk101

If it is really stuck, cutting it out isn't that bad really, particularly on a stem. Seat post is more painful to cut out.

Realize you CAN put more force on a frame than it can take. I've bent frames trying to gorilla out a stuck stem or seat post. I have made a jig to hold the fork crown (carefully) in my bench vise, then put a long steel bar through the stem clamp (you WILL bend aluminum handlebars). I've gotten several out that way. Kroil for the win, PB Blaster is a joke. I've had panto'd stems where the stem was worth as much as the frame. So cutting it out was not a good option.

As a chemical engineer, I will NEVER recommend lye. First, it is dangerous. Secondly, it will destroy the paint. Forget it.

francophile 

This may help if you have a pickle fork handy: https://www.bikeforums.net/classic-v...tuck-stem.html

Worked like a champ for me.

merziac

PB Blaster and patience, dribble it in from the top for several days then turn it upside down and fill from the bottom and sit for several more days, rinse and repeat as necessary, again patience is key.

Last success was a couple of months ago, Merckx 10th anniversary frame with Dura Ace 7400 hidden bolt %$#@^&* stem, soak, soak, dribble, dribble wait, wait, stem in vice, 2x4 between the forkblades at the crown and Voila!, cracked loose and came apart with no damage to stem, fork, frame or Dura-Ace HS, PRICELESS.

roccobike

As bad luck would have it, I just sold both my "pickle" forks (ball joint forks) a couple months ago after they sat for many years in my tool chest. So that leaves that method out for now.
I like the idea of soaking in PB Blaster. Because the quill is loose, I'm going to try to drop the quill out the bottom of the seat tube. If I can do that I have direct access to the bottom of the alloy stem, sans the quill. I'm going to try that 2X4 prop, then put a driver inside the stem, with the frame on the 2X4s and hit it with a light sledge.

Andy_K 

I'll offer a rather unconventional method that I stumbled upon once. I recommend this only after trying the conventional tricks, but before resorting to destructive methods. The technique: leave the bolt loose and ride it. You can see the thought process that led me to this method (except that the loose bolt part was accidental). I gave up on a stem and just decided to ride the bike as it was. Then one day while I was out riding I noticed that the bars were not aligned anymore! I think the relevant effect is that you get thousands and thousands of micro-impacts and eventually it works itself loose. Chip seal would probably help. Proceed at your own risk, of course.

nlerner

I have had success with a similar method: fork crown in the vise with hardwood to protect the finish, then, after lots of penetrating oil, use the leverage of the bars to try and get the stem to move (and as Bill advised, don’t use bars you’re fond of). If it doesn’t move with reasonable force, apply more penetrating oil and wait another 24 hours.

conspiratemus1

Household ammonia is alkaline, like lye but less so, and less dangerous. I think it was Jobst Brandt who used to recommend it. The difficulty is getting it up into the stem-steerer tube interface where the galvanic corrosion is. Never had to try it but since it hasn't been mentioned yet, I thought I would.

Then there is CLR. One of the FAQs was if it could be used to remove rust from a car. The company's answer is, "We do not recommended using CLR on a car. The acids in our product should not be used on aluminum or any painted/coated surface. You can safely remove rust from car wheels (if rims are made of chrome or stainless steel only, no alloys)." That it will damage aluminum is, of course, a good thing in that you are trying to eat away at the stem to release it. That it can damage paint is not a good thing.

P!N20

I've done this with stuck cranks, too - remove crank bolt, go for a ride. I'm always surprised how quick they loosen up.

Murray Missile 

I've had great success getting stuck steel fittings out of expensive aluminum manifolds with Kroil. Soak it in Kroil and once or twice a day give the stem a good smack with a hammer and a wood block or BIG rubber mallet then using an old set of bars as suggested above try twisting it. Do this everyday, it may take a few days but it WILL eventually move and once it moves it's as good as out.

Hobbiano 

I've got a couple Trek 760 stuck stem stories.

The first one was an '84 that I picked up for $100. I bought it at night without having good enough light to look it over really well. I could see that it had some rust issues though. But what the heck - a 760 for $100? When I got back home with it the seat post did come out with some effort. I proceeded to take it apart taking note of the Superb Pro parts, corroded, pitted, Superb Pro parts. Also poked around at the rust on the top tube around the cable guides. It was rusted so deeply I poked right through to the inside of the top tube! Oh well. At least I should be able to save a few components. Well the stem was stuck. Bad. Soaked it for weeks with PB Blaster, tried heating it and submerging it in ice water repeatedly, inverted the frame and filled the steerer up with coke, and let that soak for another week, and it was still stuck. I really wanted to salvage the Cinelli stem, and the fork. Finally one day I wedged a 2x4 in the fork of a tree and placed the fork over it so it went between the blades of the fork right at the crown and twisted so hard I'm lucky I didn't injure myself, when something finally gave way. One of the fork blades broke/ bent right at the crown. I still have that frame. Maybe I can still get the stem out. It's hard to admit defeat.

The other 760 I bought as just a frame knowing the stem was stuck (can you believe it?) When it wouldn't come out with soaking and moderate force I just cut it out with a hacksaw blade. Sawed it off about 3/4" above the headset and made two slits in the inside of the stem. Then squeezed it, and it came right out. Took a little over an hour. No damage to the fork...

Last ride 76 

I'm a big fan of any sort of long duration vibration to help penetrating oil do it's job. Let parts sit on (or with stem), lean against a job-site compressor, or a generator, for hours. while ensuring there is a constant pool of oil sitting above seized section. The combination of gravity and thousands of cycles of vibrations usually leads to successful outcomes. Took 2 days, once.

I have one abject failure. A stainless steel speedplay pedal axle stuck inside a Dura-Ace 7402 crank arm. I don't think one iota of oil has ever gotten even the teeniest bit of penetration into those threads. I have even tried heating the arm with a torch, and sticking in the fridge to try to get some gap to let the oil in.

madpogue 

A FLAPS will probably "lend" you a pickle fork. Usu. you put down a deposit of the value of the tool, or just leave your cc number, and when you return it you get your deposit back (or they tear up your cc number).

But I also reckon a 2x4 of appropriate length, with a notch cut in it, would get you a similar setup.