BB stuck - cup broken!

michael franks

Retrobike Rider
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I'm servicing a bike I use mainly for commuting and have stripped it down. Bottom bracket is toast after many thousands of miles trouble free so replacement is due. Cleaned out the notches in the non-drive side plastic cup and began the removal process with trusty removal tool bolted onto the axle. Applied some pressure in an anti-clockwise direction and things did not feel right. The notches were a mess and bits of them fell out when I removed the tool. BB is therefore stuck and I'm appealing for help :)
 
Small drill in a circle then punch it through from the other side. Carefully cut out ring with hacksaw blade. Worked for me.
 
Re:

Thanks for the replies guys.


xxnick1975":1aleey5h said:
Take out the other side then chip away at the plastic

I did wonder if that's a possibility but it was getting dark, I didn't want to cause more damage and I was pissed off :LOL:

The History Man":1aleey5h said:
Small drill in a circle then punch it through from the other side. Carefully cut out ring with hacksaw blade. Worked for me.

BB is UNxx and so drive side is a metal cup which is part of the BB casing so punching it through (or through it) would take considerable force. Maybe I havn't grasped what you mean.
 
You can get the metal cup out? The bb is toast so remove from drive side. The drill nds plastic cup in circle. Punch out middle. Then saw The outer x 2. Should come out without damaging frame.
 
Re:

The plastic is so soft on those shells, it's alarming. I cut a wedge out just using a hacksaw blade, easy stuff!
Once you have the d/s cup and body out

Mike
 
Agree with THM

I bought a frame that came with the plastic cup stuck in the bottom bracket and I gently cut it in half with a hacksaw blade .... You only need to cut it once and the space allows what's left to be flex and free itself up.

Since I was holding the blade in my hand you can feel the difference between cutting through plastic and hitting metal.
 
I had one of those weird brittle German FAG road things. Jan 2015. You were all there. Just looked.
 
Re:

Thanks to all of you for your help and advice - I'm sure I'll be able to get the darned thing out. It's actually the first time I've had any real difficulty with a BB and now I'm a bit stuck for time until Sunday so I'll probably do it then. Cheers, Mike.
 
Whenever this happens I remove the BB cartridge from the drive side, (using an impact wrench if hand tools won't do it), then use a hot air gun on the plastic cup, they get really soft and you can just pry them out without any risk of damaging threads, particularly important in aluminum frames, just watch you don't blister your paint.
 
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