To the original poster:
There is a lot of "I thinks" being thrown around in this thread. I encourage you to peruse the shimano site for real data.
The 959s are not made from lighter materials. The 959s will last just as long as 540s. The bearings are the same in 959s and 540s, but the bearings in the 520s are different and not as smooth.
Last edited by Singlespeedster; 02-17-06 at 04:20 PM.