Bicycle Mechanics - Cold welded handle bar & quill

A few weeks ago I found an old Jamis Boss Cruiser bike on my local Craigslist. The bike had a few problems, including a cold welded handlebar tube and quill. Loosen the nut, and it won't budge. I've beaten it, heated it, oiled it, nothing. The bike looks like a it leaned against a wall outside for a long time.

I'd like to raise the handle bars. I figure I have a couple options:

1. Cut of the tube above the headset and find a smaller diameter tube and quill that will fit inside.

2. Take the frame to a local machine shop and have them mill out the old tube and quill.

What's the best option here?

option #1 is hard because quills have 1 diameter, your other option is cut it then use a dremel to cut lines in the old quill and then use a screw driver to pry the remaining quill out, u can cut it in pieces too but u have to be carefull... u can pry it a tiny bit to get some liquid wrench in and see what happens.

Another option is to bore it out but for that U need a big dril bit... look at the forums, a lot of those problems and ideas moving around look for stuck stem for example.

Your next option is just cut it, take the fork out and put a new fork, stem and handlebar in, is expensive but is faster and u dont have to deal for sure with a fork lean to the side. I bet both fork blades are lean to 1 side.

joelad: If it is a quill stem, you don't loosen any nut to remove/adjust it, you loosen the bolt at the top of the stem a couple of turns and then give it a sharp rap with a hammer or mallet to loosen the wedge. Maybe you are using the wrong approach. I'd try a LBS first before cutting things. Cutting is a last resort, there is no going back.

joelad: If it is a quill stem, you don't loosen any nut to remove/adjust it, you loosen the bolt at the top of the stem a couple of turns and then give it a sharp rap with a hammer or mallet to loosen the wedge. Maybe you are using the wrong approach. I'd try a LBS first before cutting things. Cutting is a last resort, there is no going back.

+1,000,000

If you don't tap the stem bolt down to free the wedge the stem wont move. And even if you did, and it didn't move, it's too soon to resort to last resort options. Bring it to a pro, and see if a bit of knowledge and skill can achieve what brute force didn't.

I have had good luck in the past by dripping some penetrating oil or similar down the tube, loosening the bolt and giving it a whack, then holding the frame steady in something and deliver a series of maniacal rapid-fire blows to the underside of the stem with a hammer. It destroys the stem but it will almost definitely come out. Alternatively, if you have a long enough bar of the correct diameter you can insert it into the underside of the fork and use that to try to push out the stem from the bottom - making sure to support the frame from the top and allowing room for the stem to move when it starts to give.

I've been using Kroil (the oil that creeps!) on it daily for over 2 weeks. I've used a 6mm wrench to loosen the nut to the point it's almost out. I've hit it from every conceivable angle. Heated the head tube with a MAPP torch til it was smoking. My bike mechanic tried to move it, and says there's not much I can do except live with it. Cold weld: when two parts rust together to form an unbreakable bond.

My problem is I'm 6'8". I need the handlebar higher to ride the bike comfortably.

I cannot imagine how you would heat the steerer tube of the fork without removing or cutting the stem. Heating the headtube of the frame outside the steerer tube is useless.

You stem can be removed. Your mechanic is just lazy or thinks you are too cheap to pay him for the time needed to get the job done. Cold welding does not so much bond the two parts as it tightens them together because the corrosion products are less dense than the original metals and so take up more space.

What size frame do you have that you can get proper bar height?

Look what I saw yesterday on ebay:

http://www.ebay.ca/itm/VINTAGE-UNIVEGA-VIVA-SPORT-BICYCLE-69-CM-FRAME-SET-/150648371585?pt=Road_Bikes&hash=item231357b981

Here's a photo of what I'm dealing with.

To me it looks as if the bike was leaning on it's left side, as that's where the corrosion is. As bad as the visible section looks, I imagine it's worse inside the tube.

215438

I also saw that frame on ebay. I'm trying to keep this bike complete, as it fits me OK. The seat is the correct height, if I can remove the stem & quill I can buy a longer tube to add the height I require.

Parts that have become corroded together and are hard to separate are much different from what I understand a cold welded joint to be.

http://www.wisegeek.com/what-is-cold-welding.htm

OK, it's corrosion welded then. The fact remains the tube will not move. After my original post, I went out and beat it with 2.5 pound dead blow hammer. Nothing loosen up.

In regards to using heat, I was pipefitter at a Naval shipyard for a number of years. We'd routinely use heat and oil to loosen corroded parts. I plan on repainting the frame, so I don't feel bad about burning off some paint.

OK, it's corrosion welded then. The fact remains the tube will not move. After my original post, I went out and beat it with 2.5 pound dead blow hammer. Nothing loosen up.

In regards to using heat, I was pipefitter at a Naval shipyard for a number of years. We'd routinely use heat and oil to loosen corroded parts. I plan on repainting the frame, so I don't feel bad about burning off some paint.

WD40 is an okay lubricant and penetrating fluid... it often works better when you set it on fire.

:)

If the stem is being sacrificed, there's no need to damage the frame also.

Remove the expander bolt and cut the stem off as high above the headset locknut as possible.

Now you can remove the fork, assuming of course, that the locknut isn't rusted in place also. With the fork out of the bike, you can try twisting the stem using 2 pipe wrenches, or heat, or dolly the fork under the crown and give the stem a good shot down to try to break the bond, then twist out.

Even if both the fork and stem are toast, at least the frame can escape unscathed.

I called another bike shop this afternoon. The woman I spoke to said they've had success removing stuck stems, but also said it's not 100%. Hopefully I can get it to them Tuesday after work.

Ooh. That does look bad! Well try your best! Is the rest of this bike in good condition? How old is it?

I was thinking exactly what FBinNY posted above. Cut off the stem right under the spot where it bulges (the connection between the steel quill portion and the aluminum extension) then merely remove the fork as you normally would by loosening the headset locknut and top race and remove the fork. Then other, better methods can be employed to remove the remaining stub left in the fork. Such as machining, cutting slots along the length of the quill, using heat, submersion in oxalic acid to brake down the corrosion, etc. Good luck!

Cheers
lverhagen

Success! Late last night I decided to give it one more try. I was resigned to the fact I would have to cut the tube, and drive it out from the bottom as FBinNY suggested.

After removing the brakes, I took the handlebar off. Then I repeatedly hit the stem with a hammer, and noticed it was going down. At the top of the stem is a rectangular flange with a matching flange that bolts down from the top securing the handle bar.
I hit the flange from the side to give a better striking area, and hit it repeatedly from underneath. It moved out slowly, but surely. When it finally came out it was covered in rusty oil. The Kroil had worked. I had to up end the frame to get the quill out, and that was *really* bad. It took a Dremel with sanding wheel to it to remove the corrosion. It all went back together fine.

What's the best tool for removing the corrosion inside the head tube? It's large area, I figure a rotary tool with a sanding drum, or some other device, would do the job.

What's the best tool for removing the corrosion inside the head tube? It's large area, I figure a rotary tool with a sanding drum, or some other device, would do the job.

For this kind of job I use home made "flap-lappers" and a power drill.

Use a rod that fits your chuck, say 3/8" x 8". Cut a slot about 1-1/2" long down one end. Cut 1-1/2" an emery cloth strip a few inches long. Put it in the slot and wind it around the mandrel, so the emery side is out. chuck it into the drill, put it into the part and power up to mid-range rpm.

Be careful never to remove it from the tube while it's spinning, as it can be imbalanced, or snap causing a safety hazard.

Thanks for the tip!

A brass or steel rod? I can find either at Home Depot.

Thanks for the tip!

A brass or steel rod? I can find either at Home Depot.

Doesn't matter, I've even made them from wooden dowel rods. Brass will be easier to slot, steel maybe less likely to get chuck marks.

BTW- I forgot to mention this earlier, take it slow and rest from time to time, the parts get hot.

"What's the best tool for removing the corrosion inside the head tube?" Search on "Brush Research Brake Cylinder Flex-Hone" it's like a bottle brush with abrasive tips, available in different sizes and grits. Chuck it up in a drill and let it spin. Should be just the ticket.