Bottom Bracket Mashed up!!!

maybe you could take a drill press to it and drill away enough material to get a hacksaw in, or enough to remove material so you no longer have a complete circle of internal threads. Then it should be pretty easy to just break away after this.

BTW, I have an eldridge grade frame too. and I´d say it´s worth it to recover it. It´s a great bike. Never had any problems with the frame. It´s my touring bike.

Getting a frame builder to fit a new BB shell will probably cost the best part of £100. You could have a new On One Inbred frame for not much more so if you can't get the old BB out I'd say ditch the frame. Old steel mtb frames come up on ebay all the time - I recently bought an old Muddy Fox frame for £20. The seatpost was seized and it needs a new coat, but I got the seatpost out after a lot of swearing and a powder coating will only cost £30.

<blockquote>Quote
<hr>maybe you could take a drill press to it and drill away enough material to get a hacksaw in<hr></blockquote>

BB cups are hardened steel, my experience trying this approach was BB cup - 1, me - nil. I would go with post #3 & #2 in that order.

good point

sounds like this is a common problem. My bb (cro mo marin again) was off thread at some weird angle, Ist bike shop couldnt fix it - returned it at no cost and suggested I try others. 2nd shop did like #3 - reamed out the original thread - cost about $ 25. I think that all the mesh of x threads has probably weakened this area so I check it often.

I'd try something likle Aero-Croil, that stuff loosens most any part, then use heat.

Worst case scenario, use a hacksaw blade, or dremel tool, cut the cup in half on opposite sides, see if you can tap it back out to English threading(1.375x24tpi, no?), or tap it to Italian. I've done this before.

Believe me, brazing in a BB shell is a pain in the ass. Mavic used to make a cool BB that didn't use any threads at all, but I'm afraid that possibly there aren't enough spindle lengths avail.

A funny story about Marin bicycles. I was racing in the 1990 Lemurian Classic in Redding, Cal. Climbing up the hill I came alongside a guy on a top of the line, actually prototype titanium Marin. It was the Prez(I think his name was Richard Buckley, IIRC). I started chattin' with him as we did the ten mile climb, and I quickly learned that Marin wasn't doing well financially. He had sponsored about ten racers(at least, they were everywhere), and the cost was exorbinant. He complained to me for about fifteen minutes, and I gazed at his beautiful ride, more like drooled... Finally, I rode a tad harder and dropped him. It was cool,that he was so open minded and willing to lament.

Whenever I install a BB, I use one part anti-sieze, to four parts grease, same goes for the seatpost.

Probably heat won't help much. Unless you can only apply quick heat to the frame. The difference in the frame and BB metal would probably tighten it.
Most engineering places would have a tool called an 'easy out'. Should work quick and simple. Just screw the tool in, it locks into the BB and screws it out.
A hack saw to cut and collapse it may help. There are blades that will cut through the metal. Or else again the engineering place will have tools that will cut it out. Engineering places are often good at doing engineering stuff.
If you are lucky may be able to cut slots to fit a make up tool to screw it out.
If the thing is generally rusted up Coke Cola that comes in a bottle is the best anti seize stuff can get. Soak 24 hours, will free most everything metal.
Brazing a new one in is a bad idea.

Your frame is pretty cheap and nasty. If the DIY methods above don't work just ditch it and get something else - it won't cost much.

As for fitting a new bb shell, any frame builder worth his salt would refuse to do it on a frame like that.

If you damage the threads geting it out, there are cheap threadless bottom brackets available. Google will find them easily enough.

Good luck