TC1

I have not -- yet. But I think I am getting fairly close. I have this frame solidly clamped in a vice, and am taking pretty good swings at a removal-tool with a 5 pound sledge now. One cup is out, and the other is moving, but still has a couple millimeters to go. The removal tool just gave up the ghost, however, as it was unable to withstand the impact.

I am becoming concerned about the damage that I may be doing to this frame, which was probably not designed for these impacts. I suppose I will find out if it cracked when I sandblast off all the paint, which is the next step. Will have to check it for bends, as well.

All I wanted to do was re-paint the frame -- I wasn't trying to perform a destructive test on my welds.

rosefarts

I’ve seen it go the other way. Where the cups pop out so easily that I’m concerned. In that situation I used the green press fit locktite to reinstall.

I can’t imagine a press fit that would be so tight as to withstand a 5lb sledge and break the tool. Even if it’s old and rusty.

Is it possible that the frame was deformed (crashed) and that a ripple is basically mechanically holding the cup in place? Or that for some crazy reason the cups have been pinned into place? Or even brazed? That would be crazy but might explain why it’s so hard.

mpetry912 

regardless of how big a hammer you are using, make sure you are transferring that energy into moving the cup

when you say "clamped in a vice" please describe your setup?

sometimes getting somebody to hold the frame right behind the headtube helps

/markp

Trakhak

Clamping the frame in the vice ensures that much of the impact is being transmitted through the frame (which is acting as a spring) and is thus being absorbed by the frame and the vice.

Take the frame out of the vice, and have a helper simply hold the frame up loosely - grabbing it through layers of shop towels or the like, to ensure that the impact force isn't being absorbed anywhere but at the point of contact - and tap the the cup out gently (while moving the point of impact a few millimeters at a time) with a blunt punch or screwdriver or whatever tool you can safely adapt to the purpose.

TC1

No. I installed these cups myself, seven years ago. They are not rusty, and the bike hasn't been crashed or otherwise mistreated. And, like I said, one is out and was tight, but the second one is really tight. It's moving, but it is recalcitrant.

They weren't this tight going in, either.

Thanks.

TC1

I am, thanks.

Let's test and see if I can post a picture for the first time, which may be worth a few dozen words.




Will all due respect, I am sure that I don't know anyone who is stronger than a 4 1/2" vise bolted to a large steel workbench, so I am sure that having a person attempt to hold the frame will not work better.

mpetry912 

+1 on that. you want to get as much energy as possible into the cup so that it moves.

and not the frame, the vice, etc

/markp

TC1

That's not how physics work, I'm afraid. The headset removal tool has purchase only on the rim of the headset cup. When my hammer makes contact with the opposite end of the tool, the resulting force must necessarily be transmitted into the headset cup, in the direction of that hammer blow.

At this point, either the headset cup will either move -- if the force exceeds the friction between the cup and the frame -- or if not, it will transmit that force to the frame and whatever else the frame is in-contact with. But the force cannot skip the headset cup. That is a physical impossibility. And since exceeding the cup/frame friction is exactly the goal, I don't care where the force goes afterward, if that goal is not met.

And Newton's second law tells us that whatever force is applied to the headset cup by the tool must be opposed by an equal force. So, if the frame is held by a person, which is weaker than a vise, we are necessarily reducing the force that can be applied to the cup -- and critically, reducing it below the threshold of the friction between the cup and the frame.

Thanks, but what you describe is counterproductive.

Trakhak

That's what the other mechanics always used to say when I suggested that "use a bigger hammer" was not always the best route to take, let alone the only route. I eventually stopped attempting to educate and instead just used my technique to remove the recalcitrant headset cup or whatever it was. I suspect other veteran mechanics here are nodding their heads in agreement. We've all encountered the "That doesn't make sense, so I won't try it" response.

Honestly, I don't know why people find this so hard to grasp - especially in cases in which it works and the bigger-hammer approach doesn't.

Anyway, you're at a point where you're worried about damaging the frame. What can you lose by trying the (literally) low-impact approach I described?

Trakhak

By the way, you say that the cup is part of the way out. Check to make sure that the cup isn't canted in the frame at this point. You need it to be as nearly flat as possible to keep it from wedging itself in place.

TC1

Time. I didn't start with a big hammer. I started with a small one, with the frame in a typical repair stand -- which resembles the strength of a human. Didn't work -- due to the physics I previously described.

Thanks, I appreciate your effort, but what you describe does not comport with the physical laws as we understand them.

shelbyfv

I've got no physics beyond HS but it seems if you whack something with a 5lb hammer and it doesn't move, something else connected might. Hopefully not the downtube. I think that may be why it was suggested someone hold the frame. Good luck!

TC1

Thanks. It's straight to within six hundredths of a mm.

smd4

What headset tool are you using? The proper Park tool is less than $40 bucks on Amazon. There are also cheaper options.

maddog34

i'd bet that the lovely orange PAINT glued the cups in place....

FBinNY 

I suggest you dosome.resesrch on how physics work in cases like this.

You might research anvils and dollys and discover how important they are to folks using hammers.

Your problem is analogous to hammering a nail into a 2x4 extending out from support.

In any case, I had positive suggestions but see you're more interested in proving you're smarter than those whose advice you"re seeking, than you are in saving your frame.

FBinNY 

I suggest you do some resesrch on how physics works in cases like this.

You might research anvils and dollys and discover how important they are to folks using hammers.

Your problem is analogous to hammering a nail into a 2x4 extending out from support.

In any case, I had some positive suggestions but see you're more interested in proving you're smarter than those whose advice you"re seeking, than you are in saving your frame.

TC1

"It's only metal. In the end, it always loses."
-- unknown




Took a break for dinner, but dropped an icecube down the headtube before I did. Two whacks after dinner, and out she came. No paint damage found, but we'll see what's underneath...

Thanks.

TC1

If that paint were sufficiently strong to do that, I wouldn't be repainting this frame.

maddog34

well... it certainly didn't Lubricate the cups, eh?
maybe the inside of the head tube was better "prepped" than the outside of the frame?

pressure creates heat.... add time and paint to the equation..

didja get that sucker out yet?
i've had a few stubborn ones, but they never required the 5 lb. sledge, just a 2.5 lb. drilling hammer and my "Do Not Use as a Punch!" punch. err, ALIGNMENT tool, placed in and tapped at three opposing locations around the cup... while holding the frame across my lap.. Some of those were in 60 year old-ish Raleighs...

you seem to have struck the mother load of sweat and swearing with this one. good luck!
Sorry to hear of the demise of the headset drift... bummer.

TC1

As a matter of fact, I own an anvil, and some dollies. Their usage is not applicable to this situation.

I've solved the problem, but if you'd like to discuss the relevant physics, we can. The bottom line is relatively simple. In order to remove the cup, we need to apply a force to it along a vector concentric with the headtube axis, and that force -- call it x -- must exceed the friction between the cup OD and the headtube ID. As previously mentioned, Newton explained to us that the force x must be opposed by an equal and opposite force exerted by the frame, call this -x. The same relationship holds between the frame and whatever supports it -- a vise, or a human, or what-have-you. I think it should be obvious that that support must be capable of resisting the x force -- otherwise the frame moves, and our energy is wasted on that movement, instead of overcoming the cup/tube friction, as was our goal.

So, to sum up, the support of the frame must be sufficiently strong to exceed the friction between the cup and tube, and increasing that strength does not hamper our efforts.


So do you think that'd work better with a person holding that 2x4?

veganbikes

TC1 You are creating quite a name for yourself in just a few posts. Relax a little, a person who knows a lot of things knows they don't know everything and knows when to say hey I guess maybe I am unsure or maybe I feel sure but don't need to be cocky about it. Relax a little nobody here cares how smart or not you are if you know something great everyone knows something but it is a wise person that knows they don't know everything.

Glad you got it out eventually but something you hammer in over paint can easily get stuck by the paint from pressure and heat and all sorts of factors you may not like the idea of that happening because you installed it but that could easily be what happened and it is fine. In the end you got the cup out but for the future as you repaint make sure you mask off the inside of the head tube (or shave the paint well so it clears the cups and make sure you properly grease those cups before going in and you will have a much easier time down the road. Grease is your friend. I know it can seem expensive to some or silly because you don't want the cups to move but it really will help here and you can get pretty cheap grease from an auto store if you don't want to get a nice tub or tube of Phil Wood Waterproof Grease (which is my favorite generally).

mpetry912 

seems like the power of thermal expansion and contraction did the trick.

glad this is resolved.

/markp

TC1

That was exactly why I made this post. Unfortunately, most respondents looked only at the age of my account, and decided that I didn't know what I was doing.

I was hoping for actual advice that I didn't know -- perhaps "Don't worry, a 5 lb sledge is nothing compared to a 200 lb rider" or "I'd sacrifice the cups and cut them off before risking that".

Didn't really get any, though.

I use Mobil 1 synthetic grease -- and probably way too much most of the time -- and whatever the Park product is called, on special occasions. I raced cars for about 25 years, and while there are certainly better wrenches than me, I understand the idea behind lubrication. These cups were greased when they went in, but the fit was apparently sufficiently tight that not much reached where it was required. Didn't know that at the time, but I do now, so I'll adjust accordingly.

Thanks.

smd4

The advice you were given was solid. You resorted to a 5 pound sledgehammer? Seriously??

You don’t know what you’re doing.