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jur	06-19-05 07:59 PM

Difference between Shimano bottom brackets

What is the difference between Shimano bottom brackets, say UN40 and UN51?

sydney

06-19-05 08:10 PM

Quote:

Originally Posted by jur

What is the difference between Shimano bottom brackets, say UN40 and UN51?

Lower number generally lower quality.

jur	06-19-05 08:13 PM

How is the difference in quality achieved? Are the bearings different, or the spindle material, or both?

MichaelW

06-20-05 03:25 AM

Bearings, seals, precision of the tapers.
This is one components which definately benefits from an upgrade.

jur	06-20-05 06:12 AM

Thanks. Now all I need to know if a Truvativ BB-03-SQ-LE is better than a UN40?

531Aussie

06-20-05 09:33 AM

Quote:

Originally Posted by jur

What is the difference between Shimano bottom brackets, say UN40 and UN51?

if the number jump is about 10 or 20ish, like from UN52 to UN72, or UN40 to UN51, it usually means better quality, but a UN53 is not really any better than a UN51, it's just a newer model. In fact, some would say that a UN70 is better than a UN73 because the UN73 is cheaper and heavier, with a steel right cup, and the UN70 is lighter with an alu cup.

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