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Fix Loose BB 1988 Bianchi Sport SX Japanese?

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Fix Loose BB 1988 Bianchi Sport SX Japanese?

Old 04-18-15, 03:01 PM
  #1  
Paul W.
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Fix Loose BB 1988 Bianchi Sport SX Japanese?

I'm getting some grinding under hard acceleration from my bottom bracket and the cranks seem to have a little wobble in them. Is tightening the BB really as simple as removing the left crank, removing the locking nut and tightening the axel nut a tiny amount? Got that from a youtube video.

Any tips, tricks, been there done that?

Last edited by Paul W.; 04-18-15 at 06:17 PM.
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Old 04-18-15, 03:15 PM
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Originally Posted by Paul W. View Post
I'm getting a some grinding under hard acceleration from my bottom bracket and the cranks seem to have a little wobble in them. Is tightening the BB really as simple as removing the left crank, removing the locking nut and tightening the axel nut a tiny amount? Got that from a youtube video.

Any tips, tricks, been there done that?
Nope, that's basically it.

However, if you're going to bother, I suggest you go the extra mile, and remove both cranks, remove the left cup, reach in and clean everything, and reassemble with fresh grease, and (if you want) new balls. Doing the whole job means added time, but since the only hard part is making the final adjustment, won't be any harder. There are plenty of tutorials on the subject.

BTW- I hope you noticed that I didn't suggest removing then right (fixed) cup. There's no need to unless it's worn and needs replacement.
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Old 04-18-15, 03:15 PM
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If you have a cup-and-cone type bottom bracket, yes, it can be adjusted in that way. But it may need more than just adjustment. If it hasn't been overhauled within the past few years, it could be well worthwhile to do so now.

If, OTOH, you have a modern, cartridge style bottom bracket, there is no adjustment to be made. Once the unit gets sloppy and/or starts making noises, it's time to look at replacing it.
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Old 04-18-15, 04:33 PM
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Rats. It's never "that" easy. Bolt, crank and lock ring came off no problem. But there isn't a big adjuster nut. Just a black inset threaded nut like thing with six indents printed BC 1.37. I'm assuming a special tool to tighten? Or I could use a hammer and awl to tap it a little tighter?

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Old 04-18-15, 04:38 PM
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Yes, you can tap it around with a hammer and "paint can" screwdriver. You may also have to hold it steady as you tighten the locknut.

If you opt buying tools, you need a "bottom bracket pin spanner" and lock ring tool. These come in a variety of prices and qualities, but you can get by without if this is expected to be a one shot repair.
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Old 04-18-15, 06:27 PM
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First, thanks for your help. Internet to the rescue again.

Second, it's fixed. No more crank wobble. It was really easy....with your help.

Third, I'm a little embarrassed cause when I took it for a test ride, the grinding was still there. Funny, I don't remember my dad teaching me to check the complicated things first, but that seems to be what I did. It was the simplest thing - a loose rear skewer. The tire was rubbing against the chain stay. Yes, I'm an idiot. Please forget my name. I think I'll hide under a rock for a while. In my defense, at least I pinpointed the noise to the right area. Just goes to show, my ears are fine, it's my brain that needs work.

Fourth, on a much happier note, I just sold my hybrid on Craigslist. All in all, a good day.

Thanks again.
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Old 04-18-15, 06:49 PM
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Originally Posted by Paul W. View Post
First, thanks for your help. Internet to the rescue again.

Second, it's fixed. No more crank wobble. It was really easy....with your help.

Third, I'm a little embarrassed cause when I took it for a test ride, the grinding was still there. Funny, I don't remember my dad teaching me to check the complicated things first, but that seems to be what I did. It was the simplest thing - a loose rear skewer. The tire was rubbing against the chain stay. Yes, I'm an idiot. Please forget my name. I think I'll hide under a rock for a while. In my defense, at least I pinpointed the noise to the right area. Just goes to show, my ears are fine, it's my brain that needs work.

Fourth, on a much happier note, I just sold my hybrid on Craigslist. All in all, a good day.

Thanks again.
I believe the right thing for the job is a 25# paper sack.
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An ounce of diagnosis is worth a pound of cure.

“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.
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