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Seized bottom bracket drive side
Hi
I have a Falcon mountain bike (British make). (the bottom bracket is the older type with loose bearings inside.) I have removed the non-drive side part of the bottom bracket but the drive side is seized solid. I have the right tool (20 pin socket) but nothing will shift it. I am told the drive side unscrews clockwise. Is this definitely true for this bike or do some of these unscrew anti-clockwise (in which case I'm tightening it instead of unscrewing it!) Can I replace/repack the bearings without removing the drive side cap? I am used a large adjustable spanner so there is no way to extend it for extra leverage as I don't have a wide enough pipe to put around it. Any ideas? Thanks Pete |
There's a reason why they call it the "fixed" cup.
While Italian bottom brackets undo anti-clockwise, I doubt that applies in your case. A quick check is to measure the width of the frame's bottom bracket shell. 68mm = English, 70mm = Italian. There's a couple of tricks to removing seized fixed cups. The first is holding the removal tool in place. A long bolt through the center or a big C-clamp, either just slightly loose, is a major help. The second is leverage. If you're working with a 12" Crescent wrench, you probably need more leverage. If you have access to a sturdy bench vise try clamping your removal tool vertically in the vise. Get someone to help you thread the frame onto the tool and hold it flat. Think for a minute about which way you need to rotate the frame and give it a spin. That trick has never failed me. Oh - and you can leave the fixed cup in place, clean it out, and replace the bearings from the opposite side. If the left side cup isn't pitted, just be sure to examine the fixed cup as well as you can with a flash light. |
Dear Retro Grouch,
You are the Man! Put it on my bench vice as advised and it worked! Thanks so much. Now I have the assembly out but there are no bearings on this side as there were on the non-drive side. It seems to be a fixed unit: CHINHAUR, BB CH46 BC 1.37" X 24T Tried to remove the spindle but it doesn't slip out... Does the spindle hammer out of this assembly or is it not a serviceable part meaning I need to replace the whole thing? Thanks in advance. Cheers from London, UK Pete |
Just replace the entire unit - take the parts into a shop and get a replacement set - traditional or cartridge.
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You have a "cartridge" type bottom bracket. These are unservicable and are replaced as a unit. Yours is a standard English threaded bottom bracket and replacements from Shimano and others will be readily available. Measure the spindle length and match it with the replacement.
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