> I was wondering if anyone could help me with a problem. I felt > play in the bottom bracket of my bike and I took it apart to see > what was wrong. It turns out the bottom bracket shell or the > threads in the frame on the drive side is stripped. They are > half the height they should be. The other side is perfect. Now > I can't tighten the fixed cup enough and it comes loose after > about 10 minutes. The bike is still ridable, but there's play. > Anybody have any ideas? I thought maybe tapping it and putting in > an insert. I've also been recommended to use Loctite to secure > it. Help would be greatly appreciated.
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Loctite is much weaker than steel and won't work. You see what happened to steel. The left hand thread on that cup is there because it is always moving. I don't know where you are located and how much you want to spend, but I had my BB fixed by a local shop that can do such repairs.
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The old thread was bored out and a new threaded sleeve made to fit the recess and silver soldered in place. This is a thin shell just thick enough to support threads. Other than that I have no suggestions.
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Well seeing from your email address, I live in Palo Alto just like you. Your suggestion sounds pretty good. What bike shop is it? Also, how much do you estimate the job to cost?
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In another recent thread, Jobst mentioned that this repair was "expensive". That descriptor can cover a lot of ground, but think about what is involved. Precision boring of the BB shell, precision turning of the new sleeve with threads at both ends. Silver brazing of the sleeve in place. Not a job for the faint of heart, or those without costly equipment and the skills to use them.
For me it was no choice with my custom frame, so I had it repaired. I don't recommend it for an off the shelf frame.
>> I was wondering if anyone could help me with a problem. I felt >> play in the bottom bracket of my bike and I took it apart to see >> what was wrong. It turns out the bottom bracket shell or the >> threads in the frame on the drive side is stripped. They are >> half the height they should be. The other side is perfect. Now >> I can't tighten the fixed cup enough and it comes loose after >> about 10 minutes. The bike is still ridable, but there's play. >> Anybody have any ideas? I thought maybe tapping it and putting in >> an insert. I've also been recommended to use Loctite to secure >> it. Help would be greatly appreciated.
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> Loctite is much weaker than steel and won't work. You see what > happened to steel. The left hand thread on that cup is there because > it is always moving. I don't know where you are located and how much > you want to spend, but I had my BB fixed by a local shop that can do > such repairs.
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> The old thread was bored out and a new threaded sleeve made to fit > the recess and silver soldered in place. This is a thin shell > just thick enough to support threads. Other than that I have no > suggestions.
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Well seeing from your email address, I live in Palo Alto just like you. Your suggestion sounds pretty good. What bike shop is it? Also, how much do you estimate the job to cost?
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In another recent thread, Jobst mentioned that this repair was "expensive". That descriptor can cover a lot of ground, but think about what is involved. Precision boring of the BB shell, precision turning of the new sleeve with threads at both ends. Silver brazing of the sleeve in place. Not a job for the faint of heart, or those without costly equipment and the skills to use them.
For me it was no choice with my custom frame, so I had it repaired. I don't recommend it for an off the shelf frame.
Jobst Brandt
for less than the cost of that repair, you should have bought a new big-tube aluminum shimmy-resistant frame just so it would seem like you'd done some homework on the subject. off the shelf is just fine. i'm your size and i have no trouble with a 60cm seat tube and a modern seat post.
for less than the cost of that repair, you should have bought a new big-tube aluminum shimmy-resistant frame just so it would seem like you'd done some homework on the subject. off the shelf is just fine. i'm your size and i have no trouble with a 60cm seat tube and a modern seat post.
You're six and a half feet tall like Jobst? You must be _really_ skinny to have developed some of your tastes in components (especially wheels).
for less than the cost of that repair, you should have bought a new big-tube aluminum shimmy-resistant frame just so it would seem like you'd done some homework on the subject. off the shelf is just fine. i'm your size and i have no trouble with a 60cm seat tube and a modern seat post.
You're six and a half feet tall like Jobst? You must be _really_ skinny to have developed some of your tastes in components (especially wheels).
for less than the cost of that repair, you should have bought a new big-tube aluminum shimmy-resistant frame just so it would seem like you'd done some homework on the subject. off the shelf is just fine. i'm your size and i have no trouble with a 60cm seat tube and a modern seat post.
You're six and a half feet tall like Jobst? You must be _really_ skinny to have developed some of your tastes in components (especially wheels).
Chalo
Dear Chalo,
As I recall . . .
Jobst is about 6'5" and about 180 or 185 pounds. He's a notorious Alpine masher and freely admits to preying on pedal eyes.
Jim is about 205 or 210 pounds. He's fond of low-spoke count wheels and suspicious of handlebars that haven't been replaced.
Chalo is about 6'8" and around 375 pounds. He breaks anvils and thinks that most posters are from Lilliput.
The BB shell was cut, welded back together and then new threads cut. Of course, this ruins the paint, but I got the frame repainted at the same time.
The repair held up well for the 3 or so years I used the frame afterwards. R.
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It turns out the bottom bracket shell or the threads in the frame on the drive side is stripped.
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Dear zoo keep
The best way to fix this, IMO, is to ream the BB out to an Italian ID & then rethread it w/ an Italian threads & replace your old cartage with an Italian BB. The downside to this is that one of the cups tends to be backed out due to the rotation of the spindles bearings. There are ways to overcome this, although except for Loctite, I can't remember any.
If the frame isn't extremely valuable, I would try the strongest Loctite suitable for this type application directly to the buggered threads. (Check their web site or phone tech rep.) The down side of this is that it might not hold or U might not be able to remove the cup @ a later date.
Good luck, John
-- R.
<> Richard Brockie "Categorical statements <> The tall blond one. always cause trouble." <> [email hidden]
The problem with the those bottom brackets is that they are square tapered which means I cannot get a really good crank set. Also, most of them are meant for racing bikes, not mountain bikes. But thanks anyway.
Well, next time you buy a new frame you'll know to get one with an American BB shell then. No threads to strip, room for a big spindle _and_ big bearings, and pretty much all the cranks made for it are stout.
I was wondering what would happen if I used a thick coating of JB weld and let it fully dry. Then use a tool to recut the threads the same size. Would that possibly work?
Try it and find out. Many speak of the miracles attainable with JBWeld.
Does Stronglight make a "no thread" BB that will work with your crank, or another crank you like? --D-y
No, all the non threaded bb by stronglight use square tapers which i personally dislike
Are there any bottom brackets with the fixed cup on the non drive side?
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dazookeeper said:
I was wondering what would happen if I used a thick coating of JB weld and let it fully dry. Then use a tool to recut the threads the same size. Would that possibly work?
Try it and find out. Many speak of the miracles attainable with JBWeld.
Does Stronglight make a "no thread" BB that will work with your crank, or another crank you like? --D-y
No, all the non threaded BB by Stronglight use square tapers which i personally dislike
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Are there any bottom brackets with the fixed cup on the non drive side?
Since it is the bearing cup at the chainwheel that nutates, the "fixed" cup must be on that side. A lock ring will not do because there is no way of making it tight enough. Why do you want to do that?
Well the lock ring has a larger amount of threads which means more thread engagement. I observed that the inner threads on the drive side are still intact and untouched becuase the fixed cup doesnt reach that far. Basically half the threads on the inside are still in perfect condition, so i was thinking about using something with more threads.
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Kevin Zhu said:
No, all the non threaded BB by Stronglight use square tapers which i personally dislike
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Are there any bottom brackets with the fixed cup on the non drive side?
Since it is the bearing cup at the chainwheel that nutates, the "fixed" cup must be on that side. A lock ring will not do because there is no way of making it tight enough. Why do you want to do that?
Oh ok. I was thinking about that because half the threads are still left as in not half the height, but half the threads in the inner part. My current bottom bracket doesnt reach those, so the inner threads are in perfect condition, while the connecting threads are stripped. The lock ring has more thread engagement or a larger amount of threads so i was thinking about maybe using the lock ring with the inner threads on the drive side.
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Kevin Zhu said:
No, all the non threaded BB by Stronglight use square tapers which i personally dislike
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Are there any bottom brackets with the fixed cup on the non drive side?
Since it is the bearing cup at the chainwheel that nutates, the "fixed" cup must be on that side. A lock ring will not do because there is no way of making it tight enough. Why do you want to do that?
I still say U should not dismiss my suggestion to ream the BB to Italian ID & rethread to Italian Spec. This is not some far out weird solution. It's practiced regularly in some circles. It's not all that expensive. There's a LBS in Santa Clara, Shaws, I believe they are capable of doing this. I would prefer this to the Strong light, Mavic tapered cartage bearing. I really can't see buttering the ID w' braze, or replacing the entire shell. I am certain that an Italian cartage can be made to hold tight, although it's not as easy as an English cartage. I'm merely giving what my choices would be if I were faced w/ your problem, & of course I may not entirely correct, having never faced this problem. But I sure makes sense to me.
I had a Giant Mtn bike years ago and its BB got striped.We used the JB weld idea I just cleaned it well bb threads and the bb put a good amount of Jb to cover the whole amount of threads.Let it sit for a couple days put the cranks back on and rode like crazy held for years was still tight when I got rid of the bike. If the bb goes bad your in for some trouble don't know if it will come back out. Worked for me and only cost 5$ Held up long enough to save for a better bike ??
