Mistica1

Hi, I have this second hand vintage road bike and I want to repaint it, so I took it all apart but not the handlebar since I can't loosen it at all. There is this hex underneath the normal bolt which God knows for what reason has been screwed there. The top one doesn't move at all and the hex can be moved but nothing happens, nothing really loosens... Please see my photo to understand what I mean. Any help will be very appreciated!

oddjob2

Well the hex underneath the stem bolt indicates the prior owner had the same problem, likely a rusted in wedge underneath the stem. In any event, do you have a hex fitting for a 3/8" long handled ratchet or breaker bar? Anything over 10" should get the bolt moving.

Flip the frame over and spray rust penetrant of your choice from the steering tube hole between the fork blades beforehand and let it soak in at least overnight.

markk900

I suspect the nut is just a spacer, and the allen bolt (which looks very new) replaced the original stem bolt. Must be a long allen bolt though! Agree with @oddjob2 that the wedge is probably rusted in place, but you should be able to break the allen bolt loose a couple of turns and then give it a whack with a hammer to hopefully loosen the wedge (after doing the rust penetrant spray and letting it soak).

BTW - if it *is* a long allen bolt that probably cost the PO more than a replacement stem would have!

Scooper

Like markk900, I suspect the wedge is fused to the inside of the fork steerer tube because of electrolysis between dissimilar metals (the steel steerer and aluminum wedge).

I've had good results by turning the bike upside down, removing the front wheel, and liberally squirting Liquid Wrench penetrating oil into the steerer tube hole from the bottom of the fork crown. Wait a day or so and let gravity do the work of getting the penetrating oil into the corrosion, adding oil occasionally. Then insert a hardwood dowel a little smaller than the I.D. of the steerer tube into the steerer tube at the bottom of the crown and give it a few good whacks with a hammer.

If that doesn't break it loose, repeat the above process.

dddd

I think that the Milremo(?)stem would have a steel, conical wedge, in which case the bolt ought to come free after a good soak from below, per Scooper's advice.

Possibly, you never know, that bolt may have coarser threading than the wedge and may have been force-fitted into the wedge using heavy torque. The kluge nut/spacer is a clue that you never know what to expect.

If the stem is frozen in the steerer after the wedge gets knocked loose, don't apply much torque through the folk blades and mounted wheel, I've seen dropouts twisted and broken that way. Even worse is a weakened dropout that might result. General advice here, the OP likely already knows not to do this!

Mistica1

Thanks everyone for taking time to help me, I will try your suggestions tomorrow and see if anything what you said will work, will let you know if I made it! Thanks again!

Scooper

There are basically two ways a quill stem can be secured in the steerer tube.

On the end of that Allen head bolt is either a wedge nut or a conical expander nut. I've seen both types in steel and aluminum alloy.

If the stem is aluminum alloy and the steerer is steel, there is a good possibility there is dissimilar metals electrolysis corrosion somewhere in the mix regardless of the type of nut (wedge or conical) or the nut material (aluminum or steel).

Always, always coat the stem and the nut with a thin layer of waterproof grease before installing it in the fork steerer to reduce the risk of corrosion.

Glennfordx4

If all the above doesn't work here's a tip that lately has worked good for me. Leave the bolt in and snug it up a little, go and get some Evapo Rust rust remover, turn the bike upside down and fill the steerer tube from the bottom with Evapo Rust and let it sit. It took me a week of letting it soak but in the end I was able to remove a very stuck stem then remove the very once rusted wedge saving both to be used again ( this time with plenty of grease ). You may have to make it water tight at the top because of the nut spacer someone used but I wouldn't think it would be that hard.

Glenn

Glennfordx4

An even more drastic measure I used on a Nishiki that I needed to save the fork was to cut the stem leaving about 2" showing, I then removed the fork from the bike and used a tall Olive jar filled with Oxalic Acid and placed the fork with the stem in it. That I left soak about 2 or 3 weeks ( was busy with other things ) before removing, put the stem in my vice and it turned right out saving the fork.

Glenn

Mistica1

Thanks for those pictures, now I understand how stem is fixed, helps a lot actually. What good rust penetrant would you recommend by the way? Something not pricy if possible

RoadGuy

PB Blaster

MetinUz

Given the "unorthodox" bolt, I would expect the unexpected. How about flipping the bike upside down and shining a flashlight into the steerer tube to see if something else is going on? Your first step is getting the stem wedge out, but at this point we don't even know if there is one.

wrk101

Its not rust.

There are at least 1000 threads on removing a stuck stem. Some come out easy, some come out after a lot of work. Hopefully yours is on the easy end. I am currently cutting one out (the hard end).

Mistica1

I forgot to mention that I am based in UK and PB blaster is not sold here in shops or even online, ordering from US cost a lot with postage so not worth it. Would WD 40 work? Or maybe this famous acetone and ATF mixture?

FBinNY 

Here's how to fix.

1- remove front wheel.
2- find pipe or 2x4 to brace the fork by the bottom of the crown so nothing will be lost to frame flex.
3- use a box wrench to turn the hex nut up against the cap screw until both turn. If you cannot turn the cap screw this way, keep ramping up the torque until something gives. You might have to keep the stem from turning by gently clamping in a vie, or holding from the back with a big adjustable wench. If you break the stem bol free, raise it 1/8" and hammer back down to clear the wedge.
4- worst case scenario if the bolt won't turn is that you snap it off by over torquing (they actually break fairly easily), but that's OK. With the head sheared off, you can use a punch to drive the remainder down freeing the wedge. If it breaks near the bottom, remove the nut, and you can use the bolt as the punch.
5- if the wedge doesn't free easily, don't forget to support the fork by the crown when hammering.

4-