New bottom bracket, how do I take left cup off?
12-07-12 | 01:58 AM
#1
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New bottom bracket, how do I take left cup off?
Ok Ok I feel silly even asking this, but I got a new external bb (JIS square tapered) I dont know how to take the left cup off so I can thread it in... I've only dealt with regular road BB's which the cups slide off and on like butter.
I understand the right side is a fixed cup, and there is supposed to be a removable ring or something to take the left off, but I tried everything I could think of. Turned the cup for a minute (thinking it would unscrew), pulled, looked for a ring to remove it. no luck. Umm yeah makes me feel like I shouldn't be doing this on my own but I want to try!
Thank you
I understand the right side is a fixed cup, and there is supposed to be a removable ring or something to take the left off, but I tried everything I could think of. Turned the cup for a minute (thinking it would unscrew), pulled, looked for a ring to remove it. no luck. Umm yeah makes me feel like I shouldn't be doing this on my own but I want to try!
Thank you
12-07-12 | 02:30 AM
#3
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From: Melbourne, Oz
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I'm assuming you have the necessary splined tool and simply can't figure out how to get the left cup off, right?
I think it's a bit of a tapered press fit, and what with machining tolerances could conceivably be kinda tight. Just screw the left cup into the frame back to front, and wiggle the BB around or tap it through the BB shell via a punch - once it cracks free you should be right.
I think it's a bit of a tapered press fit, and what with machining tolerances could conceivably be kinda tight. Just screw the left cup into the frame back to front, and wiggle the BB around or tap it through the BB shell via a punch - once it cracks free you should be right.
12-07-12 | 03:26 AM
#4
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That's not an external BB, it's an internal one.
Also, your description of how the left cup removes sounds more like a cup-and-cone BB. Some of those do have a lockring on one side, but it's generally on the right and it's to lock the adjustment on that cup when the BB is installed in a frame. The BB you have is a cartridge bearing one, and won't have that. The left cup is probably just a tight fit on the cartridge - do what Kimmo said.
Also, your description of how the left cup removes sounds more like a cup-and-cone BB. Some of those do have a lockring on one side, but it's generally on the right and it's to lock the adjustment on that cup when the BB is installed in a frame. The BB you have is a cartridge bearing one, and won't have that. The left cup is probably just a tight fit on the cartridge - do what Kimmo said.
