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Cleaning out Bottom Bracket?
3 Attachment(s)
I have a frame I am building up. It has sit disassembled for some time. Please see photos. Looks like rust has built up around the threads. What is the best way to clean this out? Thanks.
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It doesn't look like rust to me.
I'd put some mineral spirits or kerosene on the threads and hit it with a wire brush. |
I've got an old set of cups that I've simply cut a groove straight across the threads on with an angle grinder. Works well for cleaning out/up threads.
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Something is stopping me from screwing in the cup on the non drive-train side. Of course this was by hand, no tools, with easy pressure.
It looks like there are some burrs, sharp metal fragments coming from where the chainstay tube meets the BB. Maybe that's what is catching. Could the end of the chainstay tube been disturbed the last time a bottom bracket was removed or installed? |
If you are having problems threading in the cup, my recommendation is to take the frame to a good LBS that has the proper tools (look for an older LBS with an old-school feel) and have them "chase" the threads with the proper thread tap. This would take less than 5min to do and probably cost you about $5 to $10...if you bought a couple things like a water bottle and a tube they might not even charge you for the job.
Or...if you were able to partially hand screw the cup in a bunch threads before it started to bind, and you believe the binding is due to slivers at the bottom bracket-chainstay junction then you can slide a tool on there and give it a tad bit of elbow grease...tighten it slightly then back it off, tighten a bit further then back off again...repeat until the parts thread smoothly....then pull it out and clean it out with a wire brush and reinstall to proper torque. Though if it were me, I would take it to a shop to have it chased. Much less hassle than potentially ruining your frame. -j |
I am less inclined to use a wire brush with steel bristles and much prefer one with brass bristles, just so that the threads aren't damaged. Don't scratch the brush across, but follow the threads round and round.
What material is the cup you are using on the non-drive side? If it's aluminium, that might be where the shavings of metal are coming from. I've had a similar problem with an older frame; I think if they were using cup and cone BBs with loose balls (or ones in a cage), the cups were probably a little thinner in width, so they didn't run into interference with the seat stay protrusion. I suppose you could keep turning with a BB tool as suggested, or take it to an LBS for chasing, but that isn't going to fix the BB protrusion without some additional effort with something like a Dremel. I could suggest that you file down the new supporting cup so its reduced width would fit. If the cup is aluminium or plastic, that wouldn't be too much of a chore, but steel might be a pain. Nice colour, by the way. What brand, year and model? |
If all else fails, a threadless BB will solve your problem for < $40 for most frames.
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Originally Posted by vintagerando
(Post 18154976)
Something is stopping me from screwing in the cup on the non drive-train side. Of course this was by hand, no tools, with easy pressure.
It looks like there are some burrs, sharp metal fragments coming from where the chainstay tube meets the BB. Maybe that's what is catching. Could the end of the chainstay tube been disturbed the last time a bottom bracket was removed or installed? |
Originally Posted by jyl
(Post 18155405)
Your pictures are all of the drive side, so they aren't much help. The BB wouldn't reach the chainstay until it is almost fully threaded in. Verify your BB is the same threading as the frame's BB shell. Then get the BB shell threads chased.
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Originally Posted by vintagerando
(Post 18154976)
Something is stopping me from screwing in the cup on the non drive-train side. Of course this was by hand, no tools, with easy pressure.
It looks like there are some burrs, sharp metal fragments coming from where the chainstay tube meets the BB. Maybe that's what is catching. Could the end of the chainstay tube been disturbed the last time a bottom bracket was removed or installed? If it is English threaded, the drive side screws in clockwise and the non-drive side screws in counter-clockwise. You probably know this, but screwing in the non-drive is counter intuitive and if you aren't thinking about it, it could be your problem. |
Originally Posted by Rowan
(Post 18155143)
Nice colour, by the way. What brand, year and model?
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Originally Posted by jyl
(Post 18155405)
Your pictures are all of the drive side, so they aren't much help.
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You haven't cleaned it yet? What's the hold up?
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Originally Posted by trailangel
(Post 18155943)
You haven't cleaned it yet? What's the hold up?
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Originally Posted by jyl
(Post 18155405)
The BB wouldn't reach the chainstay until it is almost fully threaded in.
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if the threads are Buggered up then the trip to the bike shop and havint them use the special Bicycle thread cutting tool
to 'chase the threads' will, re shape them and smooth the installation of the threaded bearing holding Parts . British And Swiss the drive side is Left hand threaded .. French and Italian Its Right hand thread.. |
Originally Posted by vintagerando
(Post 18155902)
if you look at where the tube comes into the BB (photo 3), you can get a glimps of what I am referring to. If the BB openning is a clock, look at about 6 of 7 o'clock. You can see the metal I am referring to; its the butt end of the chainstay tube sticking out. On the drive train side, its more pronounced.
http://www.bikeforums.net/attachment...9&d=1441938048 |
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