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Trying to raise a threaded stem
#1
Hi all,

I'm new to bike maintenance, and I just got an old 12-speed with a threaded headset. I wanted to raise the stem, so I loosened the top bolt, and tapped it with a wooden block, as I've read about.

Unfortunately, it seemed to be stuck, so I hit it some more, but then the bolt just fell right through, as if there were no threads. Now the bolt is just loose, and I have no way to tighten it, and the stem is still stuck. Have I done something horribly wrong? Help!

Thanks in advance
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#2
Sounds like you unscrewed the wedge expender. You first need to get the stem out than fish or turn the bike upside down to shake out the expender .

Put bike upside down and Spray some penetrating oil from the bottom of the fork into the steering head. Let it soak for a while than turn bike right side up and twist the bars back and forth with upward pressure. Once the stem is out put the expender back in place and tighten bolt on top of stem but not too much leave the expender loose, clean apply light coat of grease install set height and tighten top bolt. Do not overtighten a light grunt.

See this photo, the bolt pulls the expender up against the wedged stem and locks it.

http://www.montaguebikes.com/assets/images/ownermanual/stem-diagram.jpg
Never Give Up!!!
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#3
Hm, it's not working out for me so far. I sprayed WD 40 into the bottom of the fork (though most of it just drained out through the top of the stem) and have been letting it sit, but it's not budging. I hope it's not too rusted...

Should I do something with the locknut?
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#4
the biggest problem is getting the right leverage. A fork clamp bike rack if you have access to one would lock the bike and then offer the leverage you need to knock the stem free.
http://www.nashbar.com/bikes/Product_10053_10052_119106_-1___202594
these can be mounted on truck bed rails or 2x4's for inside vans or in your case a work bench or 2x4 to stand on to get the leverage you need.
There are two kinds of people in the world, "Those who help themselves to people, and those who help people!"
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#5
If you can hear something loose in your fork tube in the space between the stem and the crown, then the locknut is irrelevant at this point. Brace the frame as best as you can, stick a breaker arm where the handlebars would go and turn that stem to break it loose. Once it turns you will be able to pull it free. If you can't tun it, buy or borrow some PB Blaster, spray down into the bottom of the fork crown with the bike upside down, and let it sit over night and try again. When you put it back together, be sure to put a little grease on the locknut.
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#6
(05-27-2013, 12:36 AM)holdennb Wrote:  Hi all,

I'm new to bike maintenance, and I just got an old 12-speed with a threaded headset. I wanted to raise the stem, so I loosened the top bolt, and tapped it with a wooden block, as I've read about.

Unfortunately, it seemed to be stuck, so I hit it some more, but then the bolt just fell right through, as if there were no threads. Now the bolt is just loose, and I have no way to tighten it, and the stem is still stuck. Have I done something horribly wrong? Help!

Thanks in advance


Sounds like your stem is either rusted or galvanized to the fork.

If your quill stem is aluminum it's more likely galvanized to the steel fork. This normally happens if enough water or moisture gets between the fork and stem especially in the rain. If your stem is not properly greased when inserted into the fork, it will fuse to the fork over time if moisture and water gets in there.

You can verify to check if the stem is steel buy using a magnet.

If the stem is steel, then WD-40 could work for you, but it's a bit weak, but better yet LiquidWrench Penetrating oil.

However, If your stem is aluminum, any of the above I mentioned won't do a thing for aluminum oxide when it bonds/fuses to the steel..and galvanizes to the steel. This bond that it creates gets so strong to the point that it's near impossible to get off by brute force.

At this point for aluminum stems, you can get 2 liter bottle of Coke/Pepsi and flip the bike upside down.. get some kind of silicon sealant that's not strong like some kind of household silicon sealant that's safe for aquarium use... plug up the bolt hole and any part that might allow stuff to leak out. Pour coke/pepsi into the fork tip it fills up.. and let it sit in the fork a few days... you can refresh the coke/pepsi every few days.. At least try it letting it sit there for 3 full days before trying. .. The acid in the soda will break down the galvanized bonds over time.

After that try to use the handlebars as leverage twisting back and forth while pulling up..

Becareful while you do this since you can bend the fork or even damage the front wheel if you apply to much force.

I recommend that you let it setting for a full 7 days while maybe refreshing the soda about 2-3 times total. I had much better luck with a full 7 days.

You can also apply this method to removing a stuck seat post. However you'll need to remove the crankset and bottom bracket in this case.

I've pulled out 3 aluminum seatposts with no issues and 2 stems with no issues. Only the 3rd stem which was a $#*&, the bond broke and I can twist it back and forth. But it was so stuck I could not pull it out. I got it out half an inch. Eventually I decided to saw off the stem when the fork got bent, but luckly I have a spare fork I can use on that frame 1986 Schwinn passage with Columbus Tenax Tubing. Other frames and forks that I rescued were a 1988 Miyata Triplecross and a 1984 Schwinn Worldsport (4130 tubing).

Anyway If you do get it out, Make sure you grease it.. Do the same for your seatpost too.

Note: I have not tried PB blaster yet since I was looking for something less toxic such as soda But yeah having some kind of vise hold device will help, but becareful of bending the fork/frame or wheel.
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#7
So I ended up removing the front wheel and brakes so I can see up into the fork, and the expander was indeed dislodged. I couldn't get the stem unstuck (I probably could if I spent more time), but I put the expander back tight in place, and screwed the bolt back into it.

Thanks for the help!
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