Stupid Bottom Bracket - Any suggestions?

[kingoffootball]

I've been (slowly) stripping down my 1991 Karakoram Elite (for the first time in its life I would guess) and run into constant seized parts.

This weekend, I managed to get off the seized crank and most the bottom bracket, so now all that remains are the head stem cups (tried tapping out with a screwdriver) and the fixed cup of the bottom bracket.

I'm limited by tools etc as to what I can try (in the short term) but I'm really starting to wonder whether the seized fixed cup is going to completely ruin my project.

I don't have a vice, so I've not tried that technique, but I have tried Sheldon's home made tool. Using the highest quality stainless M12 bolt and nut I could get my hands on I gave it a go, and with a pressure of 13st 10lbs at the end of a 1ft ring spanner I eventually managed to strip the threads on the bolt or nut - I can't tell which because now that will not come out of the fixed cup.

Does anyone have any suggestions of ways I might get it out without damaging my frame? I'll try to find a vice I can use to try that technique, but given how much force I managed to put in without succeeding with the bolt technique I'm doubtful it will work, especially as the fixed cup is very narrow, so there isn't that much to grip in the vice.

 

[MiniNinjaRob]

Has the fixed cup still got the flats on it to fit a 36mm headset spanner?
If so, bolt the spanner to the fixed cup using threaded bar and a couple of large repair washers (see below). You can put a fair bit of force through those flats using the correct spanner BUT without clamping it on it'll slip off the side.
My bike had been sitting out in the rain for months outside a shop so probably couldn't get much worse, but it came out first time using this method.
BUT spend a week poring WD40/plusgas into the BB shell from behind to work at the corrosion/rust before attempting.
I needed 2-3ft of extension on the spanner to make it work but work it did!!

 

[coomber]

Just taken out one myself which was pretty jammed. A few nights of penetrating oil (WD40 has little effect) and just clamped it into the vice and turned the frame. Stiff, but came out easily enough.

Good luck and let us know how you get on.

 

[justbackdated]

Could try the "welding a bar on the cup' trick as the localised heat will help to release the cup, but no good if you have no access to a welder. Soak the thing in Plus Gas for a good while[several days is best] and try the vice thing if you can get access to a good quality engineers vice with fresh jaws. Don't forget it is a left hand thread, and have an assistant holding/supporting the frame with you and go nice and steady.

 

[kingoffootball]

Thanks for the suggestions. I've used WD40 and GT85 on it every day for a month or two before this latest attempt, but I'll get some Plus Gas.

I'll need to find a way to remove the bolt that's in it at the moment to try the first method (I'll add a pic of the current state when I get a chance).

If I don't managed to get it sorted within a few months I will take it to my mum's as they run a vehicle dismantlers, so I'll have every tool there is available, so can try welding it ....... I'll just make sure the cutting torch is locked away out of my reach in case my frustration gets the better of me.

I'll update any progress (or lack thereof).

 

[kingoffootball]

I should have taken photos of my efforts so far and the lengths I went to to remove the non-drive crank (saw, drill, chisel, a lot of lube and heat, then "precision blows" from a hammer).

Though that might have started a petition to prevent me from going near retro bikes in the future.

 

[The Bear]

You can call me whatever you want for suggesting this but are you turning it the right way?

 

[mechagouki]

Rob's method is the safest for both bike and knuckles (unless you are prepared to buy the expensive fixed cup remover bike shops use). I have in the past managed to remove a couple of the bastard things with a very large set of vise grips (mole grips). The one in my 1986 Ritchey would not budge despite weeks of patient soaking in penetrating lube and regular attacks using a 2 foot cheater bar over the wrench handle. In the end I resorted to using a Dremel, and the stainless steel Tange cup came out, in the words of the Slayer song: "Piece by piece".

 

[02gf74]

Rob's method is the safest for both bike and knuckles

.... that;'s fine and dsandy but OP is talking about headset cups not BB cups. :?

.... ooops actually I see there is there is mention of stuck BB cup.

which side? RH side as LH thread.

... but the same dremel techique can be used to weaken the cup.

apparently these can be smashed with chisel and hamer since they are of more brittle hadeneed steel but it takes a brave soul to do that methinks.



I would suggest using a dremel cutting disc to put one cut in the cup that would make it loose its grip on the frame then tap out with drift.

 

[kingoffootball]

Seriously, I need to sort this out as it's meant to be my main bike to ride and I've spent plenty on parts, rather than buying more and more projects!

I may have to borrow a Dremel, or similar, or see what I can do with a drill, though the big bolt that's now jammed in it is not going to make that any easier.

I still might send it down to the vehicle dismantlers to have someone remove it for me, preferably when I'm not there to wince or even worse attempt it myself.

I started a thread for the build (see sig.) but that's still not led to me trying any other approaches yet.