Seized: the death knell of a frame?

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andrew_s
Posts: 5319
Joined: 7 Jan 2007, 9:29pm
Location: Gloucestershire

Re: Seized: the death knell of a frame?

Postby andrew_s » 16 Nov 2020, 3:53pm

pwa wrote:One big plus for the threadless system that prevails at the moment is that if something goes wrong it is nearly all external and accessible, not hidden half way down a narrow tube.

That's the problem I've got at present with one of my bikes.
I've got the (cromoly) stem out OK (without any difficulty, once I'd completely removed the bolt), but the wedge at the bottom is fairly solidly seized in place, half way down the steerer. The stem itself was greased, but I'd missed the wedge.
I think chemical persuasion is in order, once I get round to it.

I had the same "failed to grease everything" problem another time with a UN72 BB. I'd greased the threads, but what seized was the inside of the adjustable cup against the cartridge body, which I hadn't greased, relying instead on whatever white stuff it is that was already present.

tatanab
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Joined: 8 Feb 2007, 12:37pm

Re: Seized: the death knell of a frame?

Postby tatanab » 16 Nov 2020, 5:21pm

andrew_s wrote:but the wedge at the bottom is fairly solidly seized in place, half way down the steerer.
I have one frame where I get that problem even with the wedge well greased. Same stem type on other machines are no problem.

I found the way to shift the wedge was to put the expander bolt up through the fork crown and into the wedge that way. Then you can see if the wedge is twisted or not and hit it from underneath to release it instead of above. Works for me. Warning - if you have an old expander bolt use that one because if your expander bolt has an allen key head you might distort the end and the allen key will not go in again. It takes a pretty hefty thump to do that, but it is possible.

Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: Seized: the death knell of a frame?

Postby Brucey » 16 Nov 2020, 5:44pm

IME the expander wedge usually only gets stuck if the stem is badly fitted in the first place. By 'badly fitted' I mean that the stem was fitted in the lowest possible position, i.e. so the expander is sat on top of the butt inside the steerer. The wedge (if it is resting on the butt inside the steerer) will then seize into position given the slightest encouragement (e.g. corrosion, or being tapped downwards to release, which only jams it worse... :roll: ).

Bolting the stable door I know, but it is always prudent to lift the stem ~3mm from its lowest possible position before tightening the expander. This way the problem is avoided. If the stem still isn't low enough this way then you need a different stem or to modify the one you have.

Just this afternoon I dealt with this exact problem on one of my own bikes. I fitted a spare bolt to the wedge, snugged a big adjustable spanner under the bolt head, and then gave it a few smart smacks upwards with a hammer. It soon came out. My excuse is that I built the bike in a mad rush five years ago and since then it has lived outdoors in the rain. The small amount of grease I put on the quill prevented seizure, but the (plain steel) wedge was quite well corroded, because I had been daft enough to fit the stem in the wrong way, i.e. as low as it would go.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

lescargo
Posts: 227
Joined: 27 Dec 2013, 11:51pm
Location: Tyneside

Re: Seized: the death knell of a frame?

Postby lescargo » 16 Nov 2020, 7:53pm

Rarely!
The old "war Babies" throw out nowt!!

As always, this is not a new problem and, something many of us have solved in our different ways with whatever we have to hand.
If necessity is mother of invention then desperation is the father of innovation!!

Is time available, can you, your clubmate or even customer wait a week for the frame back for use?
Release oil? WD40, Plus Gas?
Not for me .
Both smell like they are doing good but what extra vapour pressure do they achieve to assist the lube to permeate/creep into available space?
Diesel for me .
It really is "thin"-thin enough to form tiny droplets that disperse into air at 300psi.
Get it into seat tube via bottle cage bolt hole.
Assuming top section still intact, sealing pin and frame upside down.
check to see , unlikely, if diesel creeping out at clamp bolt slot.
Check at intervals, see if creeping out at the clamp slot; seal that and leave for a week.
Fasten seat rail clamp section in vice and twisting the frame worked to free clubmates frame!!

I don't have access to *air hammer wrench but I do have workbench with a vice.

Very useful to undo traditional b/bkts. by gripping the flats and turning the frame to break the seal.
Beware L and rt. hand threads -its easy to forget when frame is not the right way up/sideways.
Most of us do have more than one bike!
Problem gripping seat post stub to turn it-without crushing it with stillsons wrench??
A) Clamp another frame on top of stub to turn stuck set pin.
Successfully did this couple years ago removing broken carbon seat pin from my own carbon frame.

Curious-has anyone used bottle cage boss to pressurise seat-tube to assist their "release oil" to migrate between steel/ally.
There isn't space but isn't aluminium oxide porous; don't know really.

If you are left with no other alternative to cutting with cobbled-up hacksaw blade good news is , (I have one,) a padsaw blade which fits directly into early, non retractable "Stanley Knife" handle.

II expect there will be other methods /home dodges from those without w/shop facilities and "blind bearing" pullers so lets have yours for next time if ours don't work?

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The utility cyclist
Posts: 3607
Joined: 22 Aug 2016, 12:28pm
Location: The first garden city

Re: Seized: the death knell of a frame?

Postby The utility cyclist » 16 Nov 2020, 9:32pm

Had a seized BB (Ultegra Octalink) in a Principia RS6, seller obviously had had a bash at trying to get it out, never mentioned it in the sale blurb :twisted: Bike shop managed to rescue the frame and cut the BB out, There was a cut line across the threads but they cleaned out everything and it was fine, I sold it on when I bought my first carbon frame and the buyer was a decent crit racer and was well happy.

The bike shop spent significant time on doing the job but only charged me £40, probably 3 hours work so should have been £100+, that's why I keep going back to them even though I know their rates aren't the cheapest, I trust them and they do a great jo each and every time.

I also had a horrendously stuck post in a quality steel frame, I ended up selling it for peanuts after it defeated me :( buyer managed to revive it but I'd had enough time on it for my liking.
I think it really depends on how muh time you want to invest as to whether it absolutely is the death knell.

Andy Short
Posts: 52
Joined: 9 Dec 2007, 3:45pm
Location: Bristol

Re: Seized: the death knell of a frame?

Postby Andy Short » 18 Nov 2020, 3:39pm

I have removed a couple of (friends!) seized seatposts and an alloy handlebar stem by sawing. You don't have to saw right through, just enough to allow the remainder to spring a bit.
Couple of points:
WD40 is not a particularly good penetrating fluid. Plus-gas is, if not 'fresh' diesel fuel, My son also uses acetone (nail varnish remover)/vegetable oil mix, no flames!!
For hard steel parts (old BB cups, etc.), use a dremel with the fibre-reinforced cut-off wheels to slot. Carbide tipped dental drills also work as cutters with a reasonable life, if used with spray water coolant and care & PPE.....