Cannot remove cups from shell (ashtabula)
 

I've got an el-cheapo Micargi Tahiti Nexus 3 (Go ahead, laugh) that I've been riding for three or four years now. Every spring I've slowly made it a better bike - like last year I uprated to a nexus 7 hub, and for this spring improvement I'm in the process of swapping out the one-piece ashtabula for a three piece crank setup.

I got a press fit bottom bracket adapter so I can put 68mm cartridge in (go ahead, laugh some more - like I care) and ordered some "eigth-inch" brand cranks with a Tange 68x103mm bottom bracket...

I've pulled one-piece cranks apart before and this one seemed no different - pull the nut, pull the washer, unscrew the adjusting cone, pull the bearing cage on that side, wedge it out to pull the opposite side bearing cage loose, yank the crank...

But I get to the cups - and what the hell? I'm more than familiar with press fit cups I've swapped at least five sets over the past two decades... It's just these suckers are IN THERE. I'm tapping with my steel rod and duece and a half lump - alternating opposite sides - and I've managed to make a dent in the inside of the cups, but they're not moving. It's like the blasted things are epoxied or welded in!

Anyone have some advice for freeing them up before I whip out the cutting tool? I really don't want to go there since if I slip with the cutting disc I'll have borked the shell... (I know, I know, go slow and you'll be fine!)

Seems really stupid to end up destroying them just to take them out. I hit them much harder I'm going to start bending the frame.

... and yes, they were pitted before I started and need replacing anyways - what I get for riding in winter in New England. Road salt's a stone cold ***** when it comes to maintennance. I was thinking MAYBE they're just really rusted in so I've got 'em soaking in WD-40 now.

There are a couple things you can do. The first is to soak the the bottom bracket shell in some kind of solvent for about 15 minutes and then try again. If that doesn't work, rinse it off and repeat. If, after a few tries with that you still can't make them budge, you can make your own ashtabula cup extractor, which is basically a great big bolt and a bladed nut that you twist while another big nut presses against the other cup.

If you're not worried about saving the cups, then you can cut them out, carefully.

could try putting the frame in a basin of hot water. see if that loosens the hold the cups have.

Ive got a 3 peice crank on my folder bike. It originally had a 1 peice crank. Ive got an axle that has square tapers and the threads for 1 peice bb cones.
I do have a DMR adaptor cups too. So might fit them to it. I think they are simmilar to what youve got

Sounds good, except that while it would work for pressing cups in, how are you going to get the parts behind the cups to press out?

Try this.
Step one figure a way to rigidly support the BB shell by the rim so all your hammering energy goes into moving the cup, instead of being dissipated by flex.
Step two look for a decent piece of thick flat scrap steel that you can feed between the cups and lay across the lower one like a bridge.
Step three find a large diameter bolt or hunk of scrap to use as a punch, and using a serious hammer like a 4# mallet deliver a no BS solid blow to knock it out. Multiple smaller blows will only distort it, whereas one big blow will break it loose. (wear protection, especially eye protection)

If you have access to a press like an automotive bearing press follow the same steps but use the press in lieu of the hammer.

Thanks for all the advice - DArthurBrown hit it on the head with the idea of trying to pry them apart inside.

I forgot I had a small carpentry clamp - I made two wood chocks to fit inside there the same rounded shape, put them on the carpentry clamp and all sorts of fun crackling noises later, POP, one of them went flying across the room and into the bucket where I have my chain soaking in degreaser.

Having one out of the way let me get the other one with the lump and a round piece of wood I had lying around that's only slightly smaller than the diameter of the shell.

Oh, and they WERE epoxied in - there's only a fine bead of it, but I've got the 'pieces' of two epoxy rings that were holding them in.

Whiskey tango foxtrot?!? Who epoxies cups into a shell?

Micargi I guess. Another reason they're a cheap brand?

BTW, I'm shocked and pleased to see so many responses so quickly - an ACTIVE bike forums huh? I'll have to stop in more often.

You're right. These guys are amazing.