robt
Viscount
Posts: 559 
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Post by robt on Oct 25, 2015 9:57:15 GMT
I have an alloy stem and steel steerer tube fitted in a Sport frame that have grown so fond of each other over the years that they just don't want to be separated. Does anyone have any really good tips on how to tear them apart? How much heat and where best to apply it?
I have PlusGas penetrating oil, a kitchen blowtorch filled with butane, some 'freeze-it' spray and a collection of levers, workbenches and vices (apart from smoking & drinking). Short of pouring caustic soda down the head tube to dissolve the alloy, what tactics have members found most effective?
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robt
Viscount
Posts: 559
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Post by robt on Oct 25, 2015 17:08:45 GMT
Fear not, it is done. Having heated and chilled the stem and squirted it with penetrating oil, it still would't budge. I turned the bike upside down in my workmate so that the fork crown was well supported, found an old piece of c.1/2" tube that fitted through the fork crown and steerer tube to sit onto the bottom of the stem wedge nut and hit the 1/2" tube with a hammer many times, as below.  Untitled by RMT@261, on Flickr  Untitled by RMT@261, on Flickr I also managed to remove my bottom bracket axle and its crusty 30+ year-old cartridge bearings. Having tried hitting the axle with my trusty mallet to no effect, brute force became my friend again. I pulled off the bearings' outer seals and took a 3mm drill to the bearing cages, destroying them as much as possible. This allowed me to move all the ball bearings to one side of the axle, whereupon the axle could move away enough to allow the ball bearings to be plucked out one by one. Once the ball bearings and the bits of cage were all out, the axle pulled through the BB shell, leaving me with just the outer races to knock from the shell with a punch (done) and the inner races to remove from the axle (not yet done).  Untitled by RMT@261, on Flickr Here's what the removed bits look like now :  Untitled by RMT@261, on Flickr So the Sport is ready to be dropped off at the painters tomorrow. See you in two weeks! |
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Post by oldroadietehachapi on Oct 25, 2015 17:14:42 GMT
It looks like you got it! I have used household ammonia for stems stuck in forks and seat posts stuck in frames; just turn it upside down and let it soak.
Jim
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robt
Viscount
Posts: 559
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Post by robt on Oct 25, 2015 17:19:31 GMT
Jim,
Many thanks for the ammonia tip, but I finally found the right direction to hit it from, which did the trick.
For interest, the 22" frame weighs 1875 grammes (4lbs 2oz) and the fork weighs 850 grammes (1lb 14oz). Both weights without any headset, BB or other fittings.
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Post by jazzkifli on Mar 24, 2023 21:31:06 GMT
Hi Robt,
I have a similar problem with the stem. Sadly (or not?) I have a 3rd gen Death Fork which have no hole from the bottom, therefore I can’t use a hammer. How can I remove the stem without any damage?
Regarding the bottom bracket, thanks for your solution, maybe I have to do the same with the small drill…
KR
Viktor
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Post by brianbutler on Mar 24, 2023 23:56:36 GMT
Hi Robt, I have a similar problem with the stem. Sadly (or not?) I have a 3rd gen Death Fork which have no hole from the bottom, therefore I can’t use a hammer. How can I remove the stem without any damage? Regarding the bottom bracket, thanks for your solution, maybe I have to do the same with the small drill… KR Viktor Too bad. That is the second worst problem you can have. The only one worse is a stuck seatpost.
First a few basics. I assume you have loosened the stem bolt, backed it out several millimeters, and hit it with a hammer to dislodge the wedge at the end of the quill. This is the normal procedure to remove the stem. Beyond that, you can try various combinations of lubrication, heat, impact, torque, etc. Personally, I would immerse the joint in Evaporust for a few days as a first course. Ultimately you might have to cut off the stem and replace both the stem and the fork.
A stuck seatpost is worse because cutting things off does not solve the problem. There is often no solution and the frame is scrap.
I frequently buy bikes sight unseen, but if I want the frame I include a caveat that the seatpost and stem are not seized.
Good luck.
Brian
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Post by oldroadietehachapi on Mar 25, 2023 0:06:23 GMT
Stuck stems can be a tricky and difficult job; sometimes nothing works. Nevertheless, I would try loosening the stem bolt and then (if possible) tap the wedge (with punch and mallet) down a bit. Then remove the stem bolt and (using the bolt hole) fill the steerer tube with ammonia. Maintain the ammonia level let it sit for a day or two. You will need to securely (clamp if possible) hold the fork in place (near the crown) and try twisting the handlebars, also a tap or two with a hammer (dampened by a block of wood) may help. Be careful not to twist the fork tubes which would ruin the fork. Persistence is paramount.
Good Luck! Jim |
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Post by brianbutler on Mar 25, 2023 1:01:32 GMT
Stuck stems can be a tricky and difficult job; sometimes nothing works. Nevertheless, I would try loosening the stem bolt and then (if possible) tap the wedge (with punch and mallet) down a bit. Then remove the stem bolt and (using the bolt hole) fill the steerer tube with ammonia. Maintain the ammonia level let it sit for a day or two. You will need to securely (clamp if possible) hold the fork in place (near the crown) and try twisting the handlebars, also a tap or two with a hammer (dampened by a block of wood) may help. Be careful not to twist the fork tubes which would ruin the fork. Persistence is paramount.
Good Luck! Jim I will try the ammonia trick the next time I have a stuck stem. How to you keep ammonia from running out through the bearings and/or bottom of the fork crown? Maybe remove the handlebars and immerse the whole head end? I assume the ammonia is acting on the aluminum and its salts. What gases are produced by this method? Is is something I can do indoors?
Brian
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Post by oldroadietehachapi on Mar 25, 2023 3:30:52 GMT
Good questions, aluminum oxide reacts with ammonia to produce aluminum nitride and water. Yes it will leak past the bearings; you can slow the leaking by pulling electrical tape into the gap above the fork crown. I would only use consumer grade ammonia as commercial grade may damage the paint and is more hazardous to handle. I think such things should be done outside if for no other reason than the mess. My own experience has only been with a seat post, so the upside down bike contained the ammonia. Since it did not leak out, I refreshed it a few times to help maintain the reaction. The big concern with ammonia is to not mix it with cholrine bleach; this it produces deadly chlorine gas.
Cheers
Jim
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Post by jazzkifli on Mar 25, 2023 9:04:33 GMT
Hi guys,
Thanks for the many advice!
Yes, the wedge moves freely, but I can’t make to move.
I simply tried to turn it with the handlebars while the front wheel was between my legs.
I try it out was you wrote.
However, should I remove the stem when the fork moves without any issue?
I’m just curious how the bearings are. But I think I can let it so.
Thanks
Viktor
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Post by brianbutler on Mar 25, 2023 11:43:17 GMT
Hi guys, Thanks for the many advice! Yes, the wedge moves freely, but I can’t make to move. I simply tried to turn it with the handlebars while the front wheel was between my legs. I try it out was you wrote. However, should I remove the stem when the fork moves without any issue? I’m just curious how the bearings are. But I think I can let it so. Thanks Viktor If you get it moving, just pull the stem out. The bearings touch only the steerer tube, not the stem. After pulling the stem, you can remove the bearings. To do that, support the fork with a bungee cord so it does not fall and unscrew the locknut, spacers, and upper cone from the steerer. Take out the upper bearing (loose ball or cage. Turn the bike over and lift the fork out. Remove the lower bearing. If you are replacing the headset, you must also remove the "fork crown race". It is the ring at the base of the steerer tube just above the fork crown. You can do that by knocking it off with a punch. Sometimes I tap a razor blade around the seat as a wedge to get it started. Finally, remove the upper and lower cups from the frame by inserting a pipe and knocking them out.
Then come back here for advice on which headsets will fit and how to install them.
Brian
Brian
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Post by brianbutler on Mar 25, 2023 11:49:26 GMT
Good questions, aluminum oxide reacts with ammonia to produce aluminum nitride and water. Yes it will leak past the bearings; you can slow the leaking by pulling electrical tape into the gap above the fork crown. I would only use consumer grade ammonia as commercial grade may damage the paint and is more hazardous to handle. I think such things should be done outside if for no other reason than the mess. My own experience has only been with a seat post, so the upside down bike contained the ammonia. Since it did not leak out, I refreshed it a few times to help maintain the reaction. The big concern with ammonia is to not mix it with cholrine bleach; this it produces deadly chlorine gas. Cheers Jim So is the theory that aluminum oxidation is the culprit in stuck stems/seatposts? I also see a lot of rust and have had stuck steel setaposts. Do you think ammonia also reduces/dissolves the iron oxides? Perhaps I should have paid more attention in chemistry class.
Also along these lines - do you think anti-sieze compounds like copper grease and aluminum grease work by putting an electrical conductor between different metals to eliminate galvanic corrosion?
Brian
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Post by oldroadietehachapi on Mar 25, 2023 16:33:44 GMT
Brian wrote
"So is the theory that aluminum oxidation is the culprit in stuck stems/seatposts? I also see a lot of rust and have had stuck steel setaposts. Do you think ammonia also reduces/dissolves the iron oxides? Perhaps I should have paid more attention in chemistry class.
Also along these lines - do you think anti-sieze compounds like copper grease and aluminum grease work by putting an electrical conductor between different metals to eliminate galvanic corrosion?"My understanding is limited, but this is what I think I know. Which oxide is produced depends upon the nobility of the metals; the metal with the least nobility will react. Aluminum is less noble (more reactive) than steel and the elements the steel is alloyed with (see chart). I also have seen rust in stem areas and guess it is iron oxidation not necessarily caused by galvanic processes; I really don’t know for sure. I don’t think ammonia is very reactive with consumer grade ammonia, again, I don’t know for sure. As for prevention, anything that acts as an insulator and prevents moisture in the contact area will help. Grease helps, anti-seize is better and especially, keep the bike dry. Old bikes have often been stored outside in the rain, very destructive and begging for trouble. I prefer aluminum grease on bikes as aluminum is the same nobility as aluminum; but I doubt it really matters. I think bikes ridden in the rain should be disassembled, lubricated and anti-seize placed on stems at least once per season. I cringe when I see bikes washed with a hose (pros do this, go figure). I dry wash my bikes with automotive detailer, greasy parts first get a bit of a rag soaked with Simple Green. I only have a couple of bikes that I will ride in the rain (easier here in California).
Cheers Jim
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Post by brianbutler on Mar 25, 2023 18:18:33 GMT
Brian wrote
"So is the theory that aluminum oxidation is the culprit in stuck stems/seatposts? I also see a lot of rust and have had stuck steel setaposts. Do you think ammonia also reduces/dissolves the iron oxides? Perhaps I should have paid more attention in chemistry class.
Also along these lines - do you think anti-sieze compounds like copper grease and aluminum grease work by putting an electrical conductor between different metals to eliminate galvanic corrosion?"My understanding is limited, but this is what I think I know. Which oxide is produced depends upon the nobility of the metals; the metal with the least nobility will react. Aluminum is less noble (more reactive) than steel and the elements the steel is alloyed with (see chart). I also have seen rust in stem areas and guess it is iron oxidation not necessarily caused by galvanic processes; I really don’t know for sure. I don’t think ammonia is very reactive with consumer grade ammonia, again, I don’t know for sure. As for prevention, anything that acts as an insulator and prevents moisture in the contact area will help. Grease helps, anti-seize is better and especially, keep the bike dry. Old bikes have often been stored outside in the rain, very destructive and begging for trouble. I prefer aluminum grease on bikes as aluminum is the same nobility as aluminum; but I doubt it really matters. I think bikes ridden in the rain should be disassembled, lubricated and anti-seize placed on stems at least once per season. I cringe when I see bikes washed with a hose (pros do this, go figure). I dry wash my bikes with automotive detailer, greasy parts first get a bit of a rag soaked with Simple Green. I only have a couple of bikes that I will ride in the rain (easier here in California).
Cheers Jim
Funny how there are definite regional differences in bike care. Here in New England, you will rarely find a bike that has been stored outside for more than a season. It has already been taken to the dump. It rains at least once a week so bikes are frequently ridden in or after rain. That means they get wet and muddy. You pretty much have to wash them off with a hose. But I have never noticed that it causes a problem. Better grade steel like Reynolds 531 and other CroMo steels don't seem to rust easily. The real problem is winter cycling because the roads are treated with various anti-ice compounds. It used to be rock salt and sand laid down after plowing, but now they spread a thin layer of a green crystalline substance before it snows and it prevents the snow and ice from sticking. This stuff mixes with melted snow and eventually coats the bike. It is corrosive and I rinse it off a couple times during the winter. I usually dedicate a single bike for winter duty and completely overhaul it in the spring.
Keep in mind, my bikes are not collector's items. I think my average purchase price is about $50 and then another $100 for tires, cables, handlebar tape, chain, and lubricants. These are riders and I get a kick out of their humble lives.
Brian
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