Badly Stuck Bottom Bracket Cup

[wild]

I've started the repairs to the 86 SR500 and have already run into issues. First, the pedals have grown to the crank arms, and then the bearing preload cup is badly galded to the aluminum to the point where the pin wrench sheared off trying to budge it. I've started grinding a relief slot in the cup hoping to relieve a little tension on the threads, but I am worried that the threads may come out of the bracket with the cup. If anybody has some sage words of wisdom regarding this problem, I'd love to hear them. I did order a new cartridge to replace the old bearings with if this will come out.

 

[black lightning 1987]

Is it just the left side cup that is stuck? I would soak it with Kroil, give it a couple of good knocks laterally from each side (use punch from inside the BB shell), and see if it will budge. If not I might tap a couple of the pin holes out to 10-32 and screw in long cap screws. Lever against the screws. Perhaps have someone knock the cup laterally while you try to turn it. Next step might be heat - propane torch on interior of BB shell while attempting to turn the cup.

 

[wild]

Is it just the left side cup that is stuck? I would soak it with Kroil, give it a couple of good knocks laterally from each side (use punch from inside the BB shell), and see if it will budge. If not I might tap a couple of the pin holes out to 10-32 and screw in long cap screws. Lever against the screws. Perhaps have someone knock the cup laterally while you try to turn it. Next step might be heat - propane torch on interior of BB shell while attempting to turn the cup.

Thanks for the input. I thought of increasing the pin hole size, but this stuff is hard, even for a good bit. I'm not certain a small tap wouldn't break off, but will save that suggestion for a last ditch effort. Heat will probably help once I get a a better purchase on the face. In order to do that I need to remove the cables and runners and just might strip the whole frame for an early refurbish project. At my age I don't like to plan too far in advance. LOL

 

[wild]

Here is the part after being soaked overnight in penetrating oil, face ground for a better purchase, and frame heated. All I managed was to twist the piece of steel that I used for a wrench. I tried getting a high speed hacksaw blade in there to split the cone, but this stuff is harder than last year's Christmas candy!

 

[black lightning 1987]

Sorry, I didn't think about it being a cup for a loose ball bottom bracket and how hard it would be.

Kroil works where other penetrating oils won't. You can find it on eBay. About all I can suggest for gripping the cup is a better version of what you've done. Widen and deepen the slots and get a good fitting piece of steel in there, as thick as you can make fit. I would weld a bolt to it so it you can put a washer and nut inside the cup to keep it tight to the cup. Clamp the steel in a vise and twist the frame.

 

[wild]

I drilled a small hole in the bottom of the frame to get a little more oil in. Tomorrow is another day. It is a shame that the bike was so poorly cared for, although it does have enough good parts that I can get my money back if I can't get this out.

 

[wild]

Finally! I went shopping for a carbide cutter to tackle the hard steel of the cone. After much grinding, I heated the bottom and applied a three foot cheater to my flat metal wrench. This thing screamed all of the way out, and I thought for certain that the threads would be ruined. Everything has turned out fine, but I think I will refinish the frame while it is apart.

 

[black lightning 1987]

I'm very happy that you got it out. Looking forward to pics of the frame built up.

 

[jimwise68]

Good effort on that mate. Bet you were so relieved to see the internal thread survived.

 

[wild]

Good effort on that mate. Bet you were so relieved to see the internal thread survived.

Relieved and surprised. I feel much better about stripping the paint and fixing the corrosion on the frame now that I've seen how tough it is.

 

[wild]

I'm very happy that you got it out. Looking forward to pics of the frame built up.

I thought that I was going to regret swapping the Schwinn all the while that cone was squealing as it came out, but now I'm happy with the trade again.

 

[black lightning 1987]

Glad that we don't have to get in to alternative BB retention (Italian threading, Mavic threadless, etc.)

 

[wild]

Glad that we don't have to get in to alternative BB retention (Italian threading, Mavic threadless, etc.)

You me both!

 

[Zachariah]

Goooooaaal!!!!

 

[wild]

Goooooaaal!!!!

LOL!