Migsc

Hey guys,

I have a 1987 Bianchi Sport LX and the bottom bracket cup snapped inside the frame. No idea how this happened but now I've got half the cup in there still without a clear way to pull it out. Any tips? I was thinking if I had a carbide drill bit, I could drill a little hole into it and use a Snap Ring Plier tool to rotate it out? I tried a normal drill bit but it's not really making a dent into the material. photos.app.goo.gl/KpjYCbhioD85Gia97

Cheers,
Miguel

Dan Burkhart 

Pic assist

Not sure that a snap ring pliers will do it. The hole might help to get purchase for a chisel to hammer it out by rotating it. If it's an Italian BB, which is likely, it will be lefty loosey

JohnDThompson 

You could use a hacksaw blade to cut through it in a couple places to separate it from the shell. The blade might cut a little into the shell threads, but nothing a quick chasing of the threads wouldn't put right.

mpetry912 

Not sure I can add much to anything John might suggest - except that a hacksaw into a hardened cup might be pretty slow. Maybe you can make a notch at the spot where the ring remnant goes across the seatstay (where it says (drill a hole here in the pic) . Use that notch either to try and turn the "remnant" or maybe split it. Careful not to distort the shell where it's thin at that point.

I think getting under the broken part is your best shot. Use best shop practices here, safety glasses and use some Kroil or PB Blaster, and then get in there and break it loose or break it up. Brace the frame as best you can to get maximum transfer of force into the part.

Tuff problem. Good luck with it.

Mark Petry
Bainbridge Island, WA USA

WizardOfBoz

Many approaches possible.

Clean the grunge out with mineral spirits and soak the thing with Kroil (a penetrating oil). Either cut some notches (more on that below) or get purchase with a drift (a punch), or use a chisel to get purchase and try to spin it out.

If that doesn't work the idea to split the ring would be my next approach. Because bearing races are hardened, you may have difficult using a standard high-speed steel hacksaw blade. I'd use a diamond or ceramic cutting wheel in a Dremel tool, cutting at about a 45° angle due to access limitations. As John pointed out, this might damage the threads. But if you are careful this should be minimal and you could then chase the threads with a proper tap to restore them.

There's another trick that is used in machine shops, which is heating the bottom bracket shell to expand it. Industrially one uses a torch typically. You could use a hot air blower (not a hair dryer, a proper workshop hot air blower). But you'd probably damage the paint.

Last, others have suggested breaking the cup with a chisel. Doable, but I'd pre-cut some slots first (using the Dremel and an abrasive disk).

dedhed

This is a p[plastic one but same principal

https://i.stack.imgur.com/Sudqn.jpg

Crankycrank

I have to ask but have you tried to coax it out with just using a screwdriver or chisel on one of the rough spots of the broken piece. A long shot but it may turn easily enough and worth a try. You could also possibly use a "tailpipe expander tool" available as a free loaner tool from some auto parts stores. https://www.oreillyauto.com/detail/b.../67096/4700292 You may be able to fit a 1 1/8" size in there but they are harder to come by from loaner shops as most are min. 1 1/2". Anyways you just expand the tool to grab on to the bearing piece and unscrew it.

Migsc

Thanks for the reply/help and pic assist (Newbie here so not allowed to post images). The hole was to get purchase, yea. I can't tell if it's lefty loosey until I remove the other side.

Migsc

that tool looks great. gonna see if the size would work. I got some purchase on the rough spots and was able to get a couple turns but then it got stuck. I may need to use a chisel instead of a screwdriver. thanks!

Migsc

Thanks, gonna try the notch with a Dremel and get a chisel to see what can be done to turn it out.

Wilfred Laurier

If the BB shell (the part of the frame that the bearing cups thread in to) is 70mm wide then the right hand side is right hand threads. Italian BBs have a 70mm shell width (compared to 68mm for most English BBs), and Italian BBs have RH threads (turn CCW to loosen) on both sides.

If the shell is 68mm wide then the drive side threads are reversed and need to be turned clockwise to remove.

Migsc

Thanks for the help. Its 68mm wide! so the drive side is reversed.

WizardOfBoz

Don't forget to clean it (ideally you can use a scribe to dislodge any crud next to the ring in the threads, but even a toothbrush, with min spirits* will work). Then use penetrating oil like Kroil or PB Blaster.

Good luck.

Wilfred Laurier

Makes sense. Italian BBs were abandoned many years ago as the drive side threads tend to unscrew due to precession. Even most Italian brands of bikes came with English BBs for decades before *ugh* press fit BBs became the standard.

Bill Kapaun

If it's BSA threading, maybe there's a pipe tap close enough that may work as an EZ out?

ThermionicScott 

It's a Japanese-made frame, so it would be British threaded.

dabac

One of these: https://www.amazon.com/Bon-Tool-24-5...2551258&sr=8-3 will cut hardened steel, albeit slowly. You may need more than one blade.
Or do the Dremel approach. I’d probably simply use a cylindrical grinding bit and get to it.
But probably not, since I have a welder. So I’d dig out a suitably sized piece of scrap metal and try to weld it in there, with enough protrusion to make it easy to grab and twist.

WizardOfBoz

Forgot about that approach. Then again, not everyone has a welding machine. An advantage of this, in addition to providing something to grab onto to turn, is that it hits the part with heat which may loosen things up.

sch

Probably be a good idea to check with local shops about chasing the BB threads after you
do get the piece out. Removal process likely to bugger at least some threads.

mpetry912 

Wait wait wait. I was IMing with another list member and he mentioned something I'd not thought of.

Before you get out the heavy artillery - is this a steel cup that broke off ? Or maybe it's aluminum or plastic ? Let's see a pic of what came out please.

Mark Petry
Bainbridge Island, WA USA

SBinNYC

There's something called an internal pipe wrench.

A normal pipe wrench will turn a pipe by digging into the outside of a pipe. An internal pipe wrench will grip the pipe from the inside. Size the internal pipe wrench to grip only the broken cup and unscrew it.

You can use some extra material as a shim, to get a smaller internal pipe wrench to grab a larger diameter pipe. Large internal pipe wrenches get expensive.

I've done it for a broken TA fixed cup.