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#1
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What is facing a frame
Hi, a quick one. I read with interest the post about facing a frame a
few days ago. What exactly is facing a frame? I know what chasing the threads in a bb but can someone give me a simple definition? |
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#2
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A shy person asked:
Hi, a quick one. I read with interest the post about facing a frame a few days ago. What exactly is facing a frame? I know what chasing the threads in a bb but can someone give me a simple definition? This is one of the many technical terms explained in my online Bicycle Glossary. See: http://sheldonbrown.com/gloss_e-f.html#facing Sheldon "http://sheldonbrown.com/glossary" Brown +------------------------------------------+ | On Monday, when the sun is hot, | | I wonder to myself a lot: | | 'Now is it true, or is it not, | | 'That what is which and which is what?' | | --A. A. Milne | +------------------------------------------+ Harris Cyclery, West Newton, Massachusetts Phone 617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts shipped Worldwide http://captainbike.com http://sheldonbrown.com |
#3
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Me wrote in :
Hi, a quick one. I read with interest the post about facing a frame a few days ago. What exactly is facing a frame? I know what chasing the threads in a bb but can someone give me a simple definition? Facing is shaving the outer edges of the bottom bracket to make them perfectly parallel before you install the bearing cups. Same goes for the head tube before you install the headset. This kind of work is less important now than in the past. |
#4
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Me wrote:
Hi, a quick one. I read with interest the post about facing a frame a few days ago. What exactly is facing a frame? I know what chasing the threads in a bb but can someone give me a simple definition? Grinding material from the outer faces of the bottom bracket shell to make them level and parallel*. Park Tools have more info on their website. The same thing is done with head tubes for headsets. * I still don't understand how this could help with a Record BB that binds even when the right cup is loose so nothing touches either face. (That was just an experiment; I would normally fully tighten the right side). BTW, PTFE tape wasn't effective enough, so I used medium-strength Loctite Threadlocker on the last few threads of the left cup and grease on the rest. A reasonable compromise, I think. It's interesting that some BB's are pre-coated with thread-lock. ~PB |
#5
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When you haven't ridden in a long time and your bike is mocking and guilting
you, eventually you have to face it. HTH, -- BS (no, really) |
#6
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Pete Biggs wrote:
Me wrote: Hi, a quick one. I read with interest the post about facing a frame a few days ago. What exactly is facing a frame? I know what chasing the threads in a bb but can someone give me a simple definition? Grinding material from the outer faces of the bottom bracket shell to make them level and parallel*. Park Tools have more info on their website. The same thing is done with head tubes for headsets. * I still don't understand how this could help with a Record BB that binds even when the right cup is loose so nothing touches either face. (That was just an experiment; I would normally fully tighten the right side). BTW, PTFE tape wasn't effective enough, so I used medium-strength Loctite Threadlocker on the last few threads of the left cup and grease on the rest. A reasonable compromise, I think. It's interesting that some BB's are pre-coated with thread-lock. well, yes, it's a polymeric goo that binds in the threads, but it's not the same material as classic loctite. talking of which, i've just disassembled the bb of a frame i bought at sf veloswap. that thing had been fully loctited in there - the threads had been fully saturated. it answered pete biggs' recent question about loctite's effectiveness as a sealant - yes, it absolutely is. but is it necessary to have a bb so locked that it requires 400 ft.lbs to break it? absolutely not. i'd love to meet the person that did it. ~PB |
#7
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Facing is shaving the outer edges of the bottom bracket to make them
perfectly parallel before you install the bearing cups. Same goes for the head tube before you install the headset. This kind of work is less important now than in the past. In what parallel universe? Just as important today as itever was. Grinding material from the outer faces of the bottom bracket shell to make them level and parallel*. Park Tools have more info on their website. the material is not ground but milled. Phil brown |
#8
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"Phil Brown" wrote in message ... Facing is shaving the outer edges of the bottom bracket to make them perfectly parallel before you install the bearing cups. Same goes for the head tube before you install the headset. This kind of work is less important now than in the past. In what parallel universe? Just as important today as itever was. Some of the newer cartridge bottom brackets (like Phil Wood and others) use mounting rings that don't contact the outer faces of the bottom bracket shell, they just fit inside, so there is no point in facing the bb if you are using one of these. If your bottom bracket tightens against the shell, it's still needed. Likewise, all the headsets I have seen contact the faces of the headtube so facing would still be needed here. Lyle |
#9
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jim beam wrote:
Pete Biggs wrote: Me wrote: Hi, a quick one. I read with interest the post about facing a frame a few days ago. What exactly is facing a frame? I know what chasing the threads in a bb but can someone give me a simple definition? Grinding material from the outer faces of the bottom bracket shell to make them level and parallel*. Park Tools have more info on their website. The same thing is done with head tubes for headsets. * I still don't understand how this could help with a Record BB that binds even when the right cup is loose so nothing touches either face. (That was just an experiment; I would normally fully tighten the right side). BTW, PTFE tape wasn't effective enough, so I used medium-strength Loctite Threadlocker on the last few threads of the left cup and grease on the rest. A reasonable compromise, I think. It's interesting that some BB's are pre-coated with thread-lock. well, yes, it's a polymeric goo that binds in the threads, but it's not the same material as classic loctite. talking of which, i've just disassembled the bb of a frame i bought at sf veloswap. that thing had been fully loctited in there - the threads had been fully saturated. it answered pete biggs' recent question about loctite's effectiveness as a sealant - yes, it absolutely is. but is it necessary to have a bb so locked that it requires 400 ft.lbs to break it? absolutely not. i'd love to meet the person that did it. Do you think it was the Full Strength Loctite? Yesterday I had an unexpected result from the above action (small amount of threadlock): Cycled 12 miles and the cup tightened! I didn't expect it to turn in that direction, but perhaps the threadlock didn't work because the shell wasn't properly de-greased (from using grease on rest of cup). You can guess what I'm trying next. ~PB |
#10
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Pete Biggs wrote:
jim beam wrote: Pete Biggs wrote: Me wrote: Hi, a quick one. I read with interest the post about facing a frame a few days ago. What exactly is facing a frame? I know what chasing the threads in a bb but can someone give me a simple definition? Grinding material from the outer faces of the bottom bracket shell to make them level and parallel*. Park Tools have more info on their website. The same thing is done with head tubes for headsets. * I still don't understand how this could help with a Record BB that binds even when the right cup is loose so nothing touches either face. (That was just an experiment; I would normally fully tighten the right side). BTW, PTFE tape wasn't effective enough, so I used medium-strength Loctite Threadlocker on the last few threads of the left cup and grease on the rest. A reasonable compromise, I think. It's interesting that some BB's are pre-coated with thread-lock. well, yes, it's a polymeric goo that binds in the threads, but it's not the same material as classic loctite. talking of which, i've just disassembled the bb of a frame i bought at sf veloswap. that thing had been fully loctited in there - the threads had been fully saturated. it answered pete biggs' recent question about loctite's effectiveness as a sealant - yes, it absolutely is. but is it necessary to have a bb so locked that it requires 400 ft.lbs to break it? absolutely not. i'd love to meet the person that did it. Do you think it was the Full Strength Loctite? my suspicion is that it was the blue "medium strength" variety. the colors fade after cure so you can't really tell. Yesterday I had an unexpected result from the above action (small amount of threadlock): Cycled 12 miles and the cup tightened! I didn't expect it to turn in that direction, but perhaps the threadlock didn't work because the shell wasn't properly de-greased (from using grease on rest of cup). You can guess what I'm trying next. if you must, use one of the low strength versions. all you want to achieve is a binding of the thread, not permanent fixture! all the bb's i've seen that have "adjusted" themselves in use were not fitted correctly. i've never had a problem with italian threaded bb's for example. ~PB |
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