Bicycle Mechanics - BB Size

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jmraspa
04-29-06, 08:24 PM
I just bought a used ItalVega bike from a friend, and I'm having some issues with the bottom bracket. A 73mm BB is too small for the threading. I'm posting some pictures too so that someone could let me know if I'm missing something, or if I need some funky old BB. Oh, and the serial number is 3569.

http://i75.photobucket.com/albums/i306/reducedfat/Serial.jpg
http://i75.photobucket.com/albums/i306/reducedfat/SeatCluster.jpg
http://i75.photobucket.com/albums/i306/reducedfat/ForkTube.jpg
http://i75.photobucket.com/albums/i306/reducedfat/BottomBracket.jpg
http://i75.photobucket.com/albums/i306/reducedfat/Bike.jpg

Retro Grouch
04-29-06, 09:21 PM
What do you mean when you say a 73mm bottom bracket is too small for the threading?

I'm betting you mean it's too small in diameter. If that's the case, it's because you need an Italian threaded bottom bracket. They're easily available but just uncommon enough that it might require a special order by your LBS. Be careful when you install it because both sides are right hand threads. Be sure to get the right side on nice and tight.
Sheldon Brown
04-29-06, 09:24 PM
I just bought a used ItalVega bike from a friend, and I'm having some issues with the bottom bracket. A 73mm BB is too small for the threading. I'm posting some pictures too so that someone could let me know if I'm missing something, or if I need some funky old BB.

You need an Italian thread, 70 mm BB.

See: http://sheldonbrown.com/gloss_i-k.html#italian

Sheldon "36 mm x 24 tpi" Brown

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| Habit is the nursery of errors. |
| --Victor Hugo |
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jmraspa
04-29-06, 09:58 PM
Can you give me any examples of brands that would carry this kind of bottom bracket? I'm a student on the cheap, so my limit is probably about $25
Sheldon Brown
04-30-06, 10:39 AM
Can you give me any examples of brands that would carry this kind of bottom bracket? I'm a student on the cheap, so my limit is probably about $25

Shimano is the best value. See: http://harriscyclery.com/bottombrackets

Sheldon "We've Got 'Em" Brown

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| The people who live in a Golden Age usually go around |
| complaining how yellow everything looks. |
| -- Randall Jarrell |
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