Originally Posted by
Iride01
DuraAce isn't necessarily longer lasting. It's just the top of the line for Shimano. And it is optimized to work with the other DuraAce components the best of all. Shifting ability and weight will be the performance things Shimano is looking at. Longevity is probably about the same as their lower tiers, maybe even a little less since it's all about crossing the finish line first.
Chains are made to work with specific speed rears. So use a 12 speed chain for 12 speed rears. 11 speed chain for 11 speed rears and so forth. But when you get down below 9 speed rears, then 5,6,7 and 8 pretty much are just the same chain. 9 will probably work on them too reasonably.
I was watching Silca's videos on drivetrain friction and longevity and not that any of that actually means anything to me in real life, (because i'm just a rider now, not a paid pro competitor) I'm an experimenter, so when I hear or see things I often times put them to the test just for experiments's sakes. This way I can physically see how stuff works, and have the actual experience now instead of just repeating what other's say ya know?
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70's Nuovo Record Jeunet Franche Compte, '88 105 Trek 1200, '85 Victory Bianchi Vittoria, '89 Exage Bianchi Strada LX, & '11 Shimano Masi Partenza