Jay Turberville

I have a 1984 Trek 770 that I'm in the process of rescuing. It's in pretty bad shape and the aluminum handlebar stem appears to be permanently fused in the steerer tube. I've tried Liquid Wrench, WD-40, soaked the whole thing in EvapoRust, then soaked in ammonia. Hammered from the bottom. Tried to turn with leverage - but not enough to damage the fork. Nothing even budges. So I'm convinced that it's corroded/frozen and I'll have to cut and drill/saw it out. Fine. But the top headset locknut is also aluminum and also doesn't seem to want to budge. Is it similarly corrode/frozen?

I've already applied pretty strong torque with a both a good quality Campy and also a Park tool spanner. I'm at the point where I can see that I'm just starting to round the corners of the nut. The steel wrench is simply harder than the aluminum nut. I'm wondering if anybody has any suggestion before I go full brute force on it and end up destroying the nut. It appears to be the original Campagnolo headset and I'd prefer if I could preserve it.

Thanks.

Mad Honk 

Jay,
A mix of 50% acetone and 50% auto trans fluid will be the best to get some lubrication in the seized parts and perhaps loosen them enough to remove them. It takes a couple of days for the mix to penetrate the parts. Turn the bike upside down and plug the stem bolt hole and then put enough in the steerer tube to cover the stem so gravity can do it's thing. Same thing for the locknut after getting the stem free. HTH, Smiles, MH

smd4

Did you remove the wedge before banging from the bottom?

Use a good quality adjustable (“Crescent”) wrench on the nut, not a thin headset wrench. You may have to sacrifice the nut.

dedhed

Heat the locknut up

Chuck M 

I'm confused. Is the headset locknut not coming loose, or the stem expander wedge? Because I'm thinking it is the wedge the OP may be talking about. If so, loosen the bolt, rap it with a soft face hammer and then try to remove the stem.

ridelikeaturtle

Got any photos we could see? That'd help a lot.

Jay Turberville

Yes, I removed the "wedge". It isn't like the standard ones I see on most bikes. It is more of a cone and you can see from the bottom that the stem has two splits that the cone forces outward. All of these parts - including the bolt - seem to be aluminum.

I started with a large adjustable - working the adjustment snug before trying to turn. When that seemed like it was going to slip, I went and to the "for the purpose" tools. They aren't that thin at 4mm, but hopefully would give a tighter fit.

FBinNY 

As noted by others.

The first and most important step is to free the wedge by backing the bolt off 6mm (or so) and driving the bolt down with a hammer. (Use an old leather belt to protect the bolt).

IF the wedge is free and the stem still won't move, remove the wheel and dolly the underside of the crown on the end of a 2x4, or other pedestal, and use a heavy mallet to drive the stem into the fork. Once it moves 1mm or so, it should be free enough to twist and work off. (oil well so twisting doesn't heat things up and make it worse)

BTW- the key to hammering in this application is to deliver a single solid blow to the rigidly supported stem/fork, rather than repeated blows.

Deal with the lockout after the stem is out because odds are it's seized to the stem rather than the fork.

Chuck M 

Jay, try what FBinNY suggests. But it sounds like you have two issues, a stuck stem and a headset you can't loosen. I'd get the stem out before trying to disassemble the headset. As mentioned, pictures would help.

Jay Turberville

I see that I should have been more clear in my original post and have explained that the bold and wedge were removed without incident. I used a rubber mallet on the bolt.

I don't see how or why the locknut would be seized to the stem. The stem has a smaller diameter and is made of the same material - aluminum. Also, there should be a very limited area where it can even contact the locknut. OTOH, the locknut is threaded onto a steel steerer tube. So it is in very close contact with a metal that it can potentially corrode/fuse to.

Jay Turberville

The reason I originally attempted to loosen the locknut was to get better access to the top of the steerer tube so that I could maybe get some solvent or lubricant in there from the opposite direction to possibly help free the stem. Of course there's no point in trying to disassemble the headset fully if the stem is still stuck in place.

Jay Turberville

Thanks for all the input so far. Here are some photos.

Jay Turberville

Yup. I plugged the bolt hole and soaked upside down overnight with the EvapoRust and followed with the ammonia. The hope was that getting rid of any rust would help the ammonia to penetrate to the aluminum. But the EvapoRust only had about 10 hours and the ammonia maybe 4-5.

I'll give the acetone/trans-fluid soup a try when I get a couple of days where I can hog the garage.

smd4

Hmmm. Seems pretty well maintained. Sweat must have done a real number in there!

Jay Turberville

The many frame nicks and scuffs have rust. It appears to have been exposed to a fair bit of weather. But it also appears to have been ridden a lot.

The bike shop sticker shows Dairy Ashford - Houston, TX. So it has probably seen a fair bit of humidity in its day.
Interesting - that bike shop incorporated in April 1982. So this bike was one of their earliest sales. It seems the shop became "Bicycle World" at some point and closed last year. I guess I can expect no warranty service from them then.

Chuck M 

Gotcha. Did you try FBinNY's suggestion to see if force would knock it in about a mm or so?

grumpus

The stem too. The locknut will expand and hopefully loosen. The stem will try to expand and mostly fail where it is constrained by steel, but it might crack the corrosion products and allow the magic juice to penetrate better.

Jay Turberville

I did previously with the possible exception of getting solid support for the fork before whacking it. I used a steel stem bolt with a 20 mm wedge (flat side toward flat stem bottom) that fits into the 20mm ID steerer tube. Steel hammer. I'll probably do another soak and give it another go before cutting anything. I'll have to rig up a nicer support before banging on it again. That said, I have low hopes based on what I've turned up regarding aluminum stems getting stuck in steel steerer tubes. My expectation is that it will have to be cut/drilled out. But I'm not looking forward to doing that. I would like to get that nut off without destroying it tho.

Jay Turberville

Hadn't really thought about it, but heat would be a better bet with the locknut than for the stem since the aluminum expands more and is on the outside. I'm more hopeful now.

Don't have a working propane torch. You two think a heat gun would be sufficient?

FBinNY 

First of all, we never know the n skill lever of OPs, nor what they've tried before posting, nor critical details they don't mention. So you need to accept when we suggest things you might have already done.

Now to clarify. Despite what you see as a gap, your lockout is actually fitted pretty close to the stem. Water, dirt and sweat (salt) wick beautifully into that gap, system to lockout corrosion is fairly common.

Conversely, the threads are typically lubed, whether intentionally or not, so headset threads don't commonly get bound, though of course it does happen.

In any case, it is very difficult to apply enough force to free stems without twisting the fork, so the key is to brace the crown.

If you have a vice large enough to hold the crown (use leather or wood to protect it) you can it and use a pipe wrench to twist the stem, or follow my earlier advice to support the crown and drive the stem to break it loose.

Jay Turberville

I do. My point about saying that I should have been more detailed about what I'd already done was meant literally. I always appreciate it when people offer help. And my lack of completeness was just wasting other people's time.

I'm open to the possibility, but admit I'm still skeptical.

My thought as well. But the locknut is usually steel, more able to take abusive wrenching and less likely to fuse/corrode. But I hadn't really thought through how much heating the nut might help. So I'm pretty hopeful right now on the nut.

Yeah. I had used a 2x3 as close to the crown as I could get it and a long piece of aluminum shower rod through the stem's handlebar hole but didn't want to push my luck since I was still putting force on the fork legs. I don't have a vice as you describe, but I do have access to one. I'll give that with the pipe wrench a try before resorting to cutting.

Thanks. I appreciate all the input and have a few new thing to try out. Will keep the thread posted about outcomes.

FBinNY 

FWIW

BITD I was often called upon for this problem, along with frozen seatposts.

I have never failed freeing a stem by driving it in, with the crown supported on a pipe stood on a concrete floor or the saddle of a bench vise.

grumpus

It's half the temperature, but worth a go. I'd wrap the nearby paint with a few layers of aluminium foil, because a hot air gun on turbo setting blows everywhere.

Jay Turberville

Yeah - I suppose this is an easier and more direct way to apply some force. And it's not like I expect to salvage the stem at this point.

The seatpost was, of course, also stuck on this bike. But once I got it to turn a little bit it was just a matter of time and elbow grease.

JohnDThompson 

Soak with penetrating oil, apply heat, and use a spanner that grips more of the locknut, like the Stronglight Cle--93: