Originally Posted by
deathshadow60
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, 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.
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.