Help to fix my bottom bracket problem

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ericc

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I wonder if there is anybody who knows something about bicycle repair who could help give me advice on fixing my bottom bracket problem. I went out for a nice Sunday ride, and as I was returning home, I noticed that the cranks were wobbly. It was pretty bad, but the lock ring was tight so there was no risk of losing the crank on a hill. So, I decided, probably foolishly, to continue riding home. When I got back, I immediately pulled off the non-drive-side crank and removed the lock ring. I was hoping that I could tighten the bearing cup and fix the wobbling problem. No such luck. It was stuck tight. It has 6 evenly spaced pin holes, and I have the correct tool to unscrew the cup. It looks like a hairpin, with two angled pins on the business end that engage with a pair of holes. No such luck. The cup was threaded too tightly. First, I tried penetrating oil. No such luck. Then I tried a little tapping, followed by tapping on the end of the wrench. No such luck. I was able to get the corresponding cup off the drive-side end with a large crescent wrench and pull out the non-drive-side ball bearings with a pair of long tweezers. I then was able to dribble penetrating oil on the inside of the cup. Still couldn't remove it. I then used a small torch to heat the cup and the bottom bracket. Not quite enough to ruin the paint, but enough to sizzle water pretty good. Still didn't budge, either CCW or CW. According to the Internet, the threads are RH on the non-drive-side and LH on the drive side. I confirmed that this was correct. My suspicion is that the cup came loose, then the wobbling tore up the threads. Then the non-drive-side cup tore up and seized in the bottom bracket with all the torquing caused by trying to make it home.

Is this salvageable? I am tempted to TIG weld a handle onto the outside of the cup and take it off by force. I checked the Internet, and it said most bike shops will refuse to fix a frame brought in to them in this state. Another thing I can do is machine a pair of aluminum cones and pinch them with a threaded rod in the bore of the cup. Torquing on this will be sure to get the thing out, probably with a lot of collateral damage. TIG welding will probably ruin the heat treat of the bearing cup, leading to a failure later. And, pulling the cup off is only part of the problem. Reinstalling or replacing will likely need new threads. I looked for a tap on the Internet, and Park Tool has one for $590. This is more than the bicycle is worth. I am sad that one foolish ride might have destroyed my loyal bicycle. But again, in the grand scheme of things, I was probably not that bad off, since the last time I took this route, a hit-and-run red light runner struck an oncoming car and caused it to spin uncontrollably toward me. It missed, but there was no way I could have dodged it. Things happened just too fast. It took me weeks to calm down, and perhaps losing a frame on this same route is just a minor annoyance.

Could this be retrofitted with a sealed cartridge, or would there be the same issues? I'm pretty sure, given time, I could get that cup out of the bottom bracket somehow, but would it be worth taking it in? Does anybody know what the charge would be for this sort of service?
 
Could you be dealing with left hand threads. Did you try turning it the other way?
 
Yes, I did try. I said CCW and CW above. Those are abbreviations for counter-clockwise and clockwise, respectively. There is an easy way to figure out the direction of the threads on the non-drive-side that is much more clever than looking at the Internet. The locking ring threads on clockwise! That must be the thread. This is more annoying than getting a stuck chuck off a lathe. In extreme cases, one would just turn the chuck off, or if one is lucky, turn off the backing plate. Or, even just leave the chuck on the lathe and work with it as is. The bicycle is worth less than the lathe, and I cannot chuck something this large on my lathe anyway. I could get it in a mill, but I only have a small horizontal. Very challenging, and not much upside.
 
I have been through bicycle repair school. There is some chance that the bottom bracket is hosed.

It wouldn’t hurt to take it to some bike shops in your area & see if they can’t salvage the threads. It is probably possible to salvage the threads if you have the threading kit. A good repair shop should be able to do this.

I have the threading kit if you are near Santa Rosa, CA.
 
this sounds like an old 3 piece bb. I had that happen to me once on a 200+ mile across the north of England. Some how found a nice old gent in a village who tightened it back up and then welded the cup to the frame :) It got me to the other side.

No way of knowing how badly the threads are damaged until you get the cups out. It's a while since I've dealt with one of these, but I would figure out a way of cutting out one cup first. Maybe chain drill into the cup around the axle, get the center and the axle out and then use a 1 ended hacksaw to carefully cut the rest of the cup down to the threads. Do that in a couple of places and it'll come out easy. Then you can see what shape the other side is in. With the axle removed it might just come out easily.

Then get the right sized sealed bottom bracket. Most likely there'll be enough of the threads left to be able to get the new one tightened up. These have ALOT of thread engagement.
 
That's a great story @mattthemuppet2 . I'm glad you finished the ride. That is an all too familiar sinking sensation.

I was successful! The bicycle runs again! It is nice to be back riding again. I have to replace it with a sealed cartridge now. The way I got it off was to remove the DS (driven-side) cup and get the axle and bearings out. Then, I could get wilder with the torch and penetrating fluid. The longer it took, the less I was worried about cooking the bearing race. A hammer was used to tap the bottom bracket every now and then. An old guy once told me heat, time, tapping and wedges will get anything out. I couldn't use wedges, but the rest of them, fine. Eventually, one day the thing just turned. Sometimes that isn't the end of the campaign; jammed threads can give you a false sense of victory, then just shear off on you. This wasn't that kind of situation. As soon as it turned a little bit, it was just a straight march to final victory. I cleaned the threads with a stainless steel brush and everything went together just fine. I should have bought this nice entry level road bike at a garage sale that I saw for a good price, but that was just a few days before the breakdown. Now, I'm on the lookout.
 
that's awesome, you must be pleased as punch! Those sealed BBs last for nigh on forever if you don't do much off roading. I have a tube of antiseize that I use on pretty much every fastener on my bikes, makes getting things apart years down the road alot easier.

the biking stories and road side fixes I could tell you... :)
 
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