I'm currently struggling with the extraction of a totally seized BB-UN71 from a Sunn frame. Bolted the extractor tool to the spindle, non-drive side, apply large spanner, nothing. Apply a metre of pipe to large spanner, ah, there she goes, it's starting to - oh. Bugger. I now have a non-drive side cup with removed splines.
In a fit of extreme optimism, try the drive side. Same approach, stopped short of achieving the same result.
Yes, I do know which way to turn them.
Lightbulb turns on above head. Bracket is dead anyway, why not separate the drive and non drive sides from one another, thus reducing stuckness.
Removed the spindle by the simple expedient of tearing out the dust seals and plastic bearing cages, pushing all the balls to one side and twatting the spindle with a big hammer until the balls drop out. Nasty. Then smash the cartridge housing, starting with a small punch through the bottom bracket drain hole, then using a 1/2" socket extension bar and a hammer to smash out the rest. Brutal, but the result is more or less what I wanted.
12 hours of penetrating oil.
Apply heat gun until bottom bracket too hot to touch, ice on drive side cup, tool in the big vice at work, use frame to get some leverage. Oooh, that's workin .... no. I now have 2 (separated) cups with stripped splines. Both of which are still apparently welded to the frame.
Do not want to take the grinder / drill approach. I like this frame too much, and although I have a steady hand, I don't want to risk buggering the threads any further. Plus, the bearing races are still in there, and they're as hard as hell. Let's go for chemical warfare. No caustic soda at work, but we do have some fairly caustic drain cleaner. It's caustic enough to remove the anodising from the cups, and start to pit them, but after 8 hours it's starting to lose its efficiency without any particularly severe damage to the cups. It's about 5% caustic. Bloody kid's stuff. It's health and safety gone mad, I tell you! I need something like 50%, the sort of mixture that boils itself as you mix it. I'll be working late tomorrow, but will send the missus out to get some caustic soda crystals
Replacement will probably be Origin8 or Velo Orange. The other options are all heavy, second-hand, or NOS "unobtanium". Anyone got any feelings one way or another on those?
In a fit of extreme optimism, try the drive side. Same approach, stopped short of achieving the same result.
Yes, I do know which way to turn them.
Lightbulb turns on above head. Bracket is dead anyway, why not separate the drive and non drive sides from one another, thus reducing stuckness.
Removed the spindle by the simple expedient of tearing out the dust seals and plastic bearing cages, pushing all the balls to one side and twatting the spindle with a big hammer until the balls drop out. Nasty. Then smash the cartridge housing, starting with a small punch through the bottom bracket drain hole, then using a 1/2" socket extension bar and a hammer to smash out the rest. Brutal, but the result is more or less what I wanted.
12 hours of penetrating oil.
Apply heat gun until bottom bracket too hot to touch, ice on drive side cup, tool in the big vice at work, use frame to get some leverage. Oooh, that's workin .... no. I now have 2 (separated) cups with stripped splines. Both of which are still apparently welded to the frame.
Do not want to take the grinder / drill approach. I like this frame too much, and although I have a steady hand, I don't want to risk buggering the threads any further. Plus, the bearing races are still in there, and they're as hard as hell. Let's go for chemical warfare. No caustic soda at work, but we do have some fairly caustic drain cleaner. It's caustic enough to remove the anodising from the cups, and start to pit them, but after 8 hours it's starting to lose its efficiency without any particularly severe damage to the cups. It's about 5% caustic. Bloody kid's stuff. It's health and safety gone mad, I tell you! I need something like 50%, the sort of mixture that boils itself as you mix it. I'll be working late tomorrow, but will send the missus out to get some caustic soda crystals
Replacement will probably be Origin8 or Velo Orange. The other options are all heavy, second-hand, or NOS "unobtanium". Anyone got any feelings one way or another on those?
