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Old 04-17-11, 08:05 AM   #1
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BB Spindle Length Differ From Suggested

I am currently in the process of rebuilding a 72 Peugeot UE-8 and will soon be purchasing a new BB to go with a set of mid-80s Specialized Touring Triple Cranks I pulled off my 1984 Davidson Tandem. According to the Specialized Catalog, the suggested spindle length is 114.5mm for a 68mm BB. The closest spindle lengths available for the BB I plan to purchase are 113mm and 116mm, so we're only talking a difference of +/-1.5mm.

is there any real consequence of going short or long on the spindle length when the difference is only 1.5mm as in this case and what are the real effects for each scenario?
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Old 04-17-11, 08:19 AM   #2
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Originally Posted by photogravity View Post
is there any real consequence of going short or long on the spindle length when the difference is only 1.5mm as in this case and what are the real effects for each scenario?
At 1.5mm, you're probably not going to have any problems, but ultimately that also depends on how close to the limits your original spindles were.

The dangers of going too long are that your front derailleur might not reach the outer chain ring and the chain line may take on a rather acute bend, affecting shifting of the rear derailleur.

The dangers of going too short are that your inner chain ring or cranks may hit the chain stays and the front derailleur might not reach the inner chain ring.

The performance related issues are negligible considering the 1.5mm differences.
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Old 04-17-11, 08:43 AM   #3
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So given that information, I suppose going with the 113mm spindle would probably be the best choice since I can then shim the BB if there is an issue with clearance or shifting. As I'm going to be putting on upgraded front and rear derailleurs that I have laying around, I'm less concerned with the derailleurs working properly than I am with frame clearance for the chain and inner chainring.

Many thanks for your insights on this.
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Old 04-17-11, 03:27 PM   #4
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Originally Posted by photogravity View Post
So given that information, I suppose going with the 113mm spindle would probably be the best choice since I can then shim the BB if there is an issue with clearance or shifting. As I'm going to be putting on upgraded front and rear derailleurs that I have laying around, I'm less concerned with the derailleurs working properly than I am with frame clearance for the chain and inner chainring.

Many thanks for your insights on this.
With that in mind I would go for the longer of the two. Or this one at 115mm. http://www.bikeparts.com/search_resu...p?ID=BPC332268
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Old 04-17-11, 07:24 PM   #5
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Which taper is it?
It is metric/English or French?
The reason I ask is that Shimano carttridge square taper bb's come in a 68 x 115 size.
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Old 04-17-11, 07:30 PM   #6
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Which taper is it?
It is metric/English or French?
The reason I ask is that Shimano carttridge square taper bb's come in a 68 x 115 size.
It's a French threaded BB otherwise I'd consider the Shimano BB. I'm planning on getting the one from Velo Orange since it's about the only game in town, though I hear it's a quality piece so I'm not complaining.
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