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Seized handlebar stem

Cubsfan2112Cubsfan2112 Posts: 7
edited August 2018 in Road general
I've got a quill handlebar stem that is seized. I've tried several different lubricant brands and also hit the stem with the bolt stem loosened with a hammer. I hear that lubricant doesn't work because the stem is aluminum. I've heard that Ammonium can work. Please share your ideas. Thanks.

Posts

  • svettysvetty Posts: 1,904
    Invert and pour Coke down from crown. Leave for a few days then apply force.
    FFS! Harden up and grow a pair :D
  • mercia_manmercia_man Posts: 1,368
    I’ve heard of people clamping stem in a vice and using the bike frame as a lever.
  • keef66keef66 Posts: 13,286
    Take the front wheel out and rest the fork dropouts on a block of wood. Then whack the head of the loosened bolt with a hammer. That should dislodge the expander. If it's still stuck then it's likely galvanic corrosion between the alu stem and the steel steerer. If you cannot get the bars to twist while gripping the front wheel between your knees then you're going to have to flip the bike upside down and pour something down the steerer to try and dissolve it. Something acidic or alkaline.

    Coke is mildly acidic; it might work eventually. Lemon juice or vinegar are stronger, as is the stuff you can buy for descaling kettles, or the limescale stuff for toilets.

    If you want to try the alkali route, drain cleaners and oven cleaners are usually based on sodium hydroxide.

    With all these things, wear gloves and protect your eyes, and do it in a well ventilated place. If you do manage to free it, wash everything with plenty of warm water to get rid of all traces of the chemicals.
  • keef66keef66 Posts: 13,286
    Mercia Man wrote:
    I’ve heard of people clamping stem in a vice and using the bike frame as a lever.

    That works well for a stuck seatpost because it gives you a lot more leverage. Less so with a fork / steerer / stem
  • mercia_manmercia_man Posts: 1,368
    keef66 wrote:
    Mercia Man wrote:
    I’ve heard of people clamping stem in a vice and using the bike frame as a lever.

    That works well for a stuck seatpost because it gives you a lot more leverage. Less so with a fork / steerer / stem

    I’m sure you’re right. Thankfully I’ve never had a stuck stem or seatpost. I’ve always removed and greased once a year.
  • keef66keef66 Posts: 13,286
    Me too. I do a lot of dismantling and applying grease / antiseize / carbon paste on a new bike. Any component gets a critical examination and I try to imagine taking it to bits after 5 winters riding.

    Others don't like to fiddle with a shiny new bike and subscribe to the if it ain't broke don't fix it school of maintenance...
  • Thank you for all the replies. I will try your suggestions and let you know.
  • You need the repeated high impact percussion of a pneumatic rivet gun or similar.

    They are hard to find but you should be able to achieve the same affect with one of those electric impact tools builders use to break concrete. I'm not use what they are called. It might be an SDS drill.

    If you think about it, the repeated percussion of one of those small electric jobbies can break concrete much better than a massive swing with a pickaxe.
  • keef66keef66 Posts: 13,286
    Having recently acquired an SDS drill to do some light demolition I can vouch for their effectiveness. I wouldn't be taking it anywhere near a bike though :shock:
  • sungodsungod Posts: 12,685
    the al corrosion product occupies greater volume than the metal, it also is rough, the combination of high pressure and friction can jam things

    assuming it's a wedge clamp, loosen the top bolt until it's well clear, then tap it down with a hammer to free the wedge, that leaves only the corrosion holding the stem

    if you've already got lubricants in there, anything water-based will have a hard time seeping in

    acf-50 can sometimes help, but again, once you've got lubricant in there it makes it harder for anything else to penetrate

    you can try a phosphoric acid rust remover like jentolite (i'd first try flushing out the lubricant with a solvent)

    or try thermal shock - al and steel have different coefficients of thermal expansion
    - make a 'shield' out of stiff plastic/whatever to sit at the boundary of stem/headset
    - spray just the stem with freezer spray (you can also spray it into the steerer tube from the other end)
    - immediately apply force to the stem to try and twist/pull it, if you can loosen it just a bit then things should get easier
    my bike - faster than god's and twice as shiny
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