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I'm trying to remove the HANDLEBARS from the stem of my bike and the handlebars are put into the stem and secured with a bolt. However, the bolt is rusted and will not budge no matter how hard I go at it. Thanks!!

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    Penetrating oil for a few days. – paparazzo Nov 1 '17 at 1:18
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    Do you want to remove the stem from the bike, or the handlebars from the stem? – Criggie Nov 1 '17 at 5:53
  • We may be answering the question that was asked, but not answering the underlying need. What do you hope to achieve by removing the stem ? – Criggie Nov 1 '17 at 21:29
  • Remove the wheel, turn the bike upside down, and see if there is any sort of opening on the underside, at the "groin" of the fork. If so, you can put penetrating oil (or, better, oxalic acid) through the hole to reach the threads that are frozen. (See Criggie's diagram.) – Daniel R Hicks Nov 1 '17 at 22:52
  • So you want to remove the bolt that clamps the stem to the handlebar? If the bolt is not too badly mangled, and is a common hex-head bolt, you should get a socket that fits tightly (DON'T use an "English" wrench on a metric bolt!) and use a socket wrench with a fairly long handle. Of course some are "Allen-head" bolts, and for that you need the appropriate (tight-fitting) Allen wrench. You may need a short piece of pipe as a "cheater" on the Allen wrench's "handle". But first use some sort of rust-buster -- simple oil does no good. – Daniel R Hicks Nov 2 '17 at 23:39
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Sounds like you have a Quill Stem, which has a single large long bolt going down into the steerer tube, which is part of the fork.

Here's a cutaway showing what's inside. http://lh4.ggpht.com/_dNxi8h53r7s/S70SYfilDGI/AAAAAAAACBA/QJsdSj44b0I/untitled_thumb%5B32%5D.jpg

Generally speaking they're fairly corroded over time. The thing labelled Clamp in the diagram is more normally known as a wedge or expander.

So you need to get some penetrating oil into the threads in the wedge. This is not possible from above.

  1. Remove your bike's front wheel and put it aside.
  2. Flip your bike over, and identify the dark hole in between the fork legs. You may need to remove any mudguard or fender too.
  3. Squirt some penetrating oil down this hole and let it sit overnight. Probably a good idea to put some rags, paper or basin down to catch any oil that comes through. Some will sneak around the sides.
  4. After a day of sitting, try and undo the bolt.

If the bolt moves, undo it about 2 full turns and then give a gentle tap with a hammer downward. This will knock the wedge loose. If you remove the whole long bolt, the wedge will be left behind.


The reason heat didn't help is because the head of the bolt is a long way from the threads, and the heat won't carry that far. Applying heat to the outside of the bike won't really help either.

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    Get penetrating freezing oil. It freezes, which causes tiny gaps that the oil can get into. I had an alloy seatpost stuck in a carbon frame that would not budge for days. One blast of freezing penetrating oil and it popped out like it was too small for the frame. – ilikeprogramming Nov 1 '17 at 10:07
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    An impact driver (either electric or manual) can also loosen stuck bolts. Be careful of using an impact driver to tighten bolts on a bicycle though -- it's way too powerful and can break frames or sheer bolts off with ease. – RoboKaren Nov 1 '17 at 14:49
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    The final issue would be to grind away the head of the bolt carefully and give the remaining stem of the bolt a slight knock with a punch. (But this would work only if the bolt has an external hex head not an Allen head.You could still drill that one out.) – Carel Nov 1 '17 at 21:25
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    @ilikeprogramming I've never heard of that - can you please quote a brand so I can find it ? Definitely sounds like something I want in my toolkit. – Criggie Nov 1 '17 at 21:27
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    @Criggie The stuff I had was Loctite Freeze and Release: "Loctite® Freeze & Release instantly chills seized and rusted parts (bolts, nuts, studs) down to -39°C. The exceptional shock-freeze effect causes microscopic cracks in the layer of rust, allowing the lubricating ingredient to wick directly into the rust by capillary action. The assembly can be easily dismantled after allowing 1-2 minutes reaction time.". It's pretty noxious stuff though, I definitely felt like I was doing the environment a disservice by using it. – ilikeprogramming Nov 2 '17 at 0:31

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