Originally Posted by
smashndash
You could have used that exact same Aethos logic on the tarmac when it had BB30 or the Emonda when it had BB90 (which are two of the worst standards to ever exist). Weight is not the reason some BB shells are better than others. It's all about geometry.
BSA has 2 problems: 1 is that in order to accommodate 30mm spindles, the housing between the threading in the shell and the spindle must be quite thin, which reduces the stiffness of the BB unit. I can link a video that discusses that if necessary.
Second one is that BSA mandates a 68mm wide shell. Wider BB shells generally make it easier to make stiffer bikes. Hence BB90, BBright, BB386EVO, BB/PF30A, T47, BB86 etc.
T47 is just a superior standard if you know that 29-30mm spindles are going to be used and if you want maximum stiffness for minimum weight. We can acknowledge that maybe the cost of switching over isn't worth it while still acknowledging that T47 is technically superior and maybe we should have switched to it long ago.
How could I have used that same logic? Who, in the history of the horror of BB90 ever said there was nothing wrong with it? BB30 didn't have near the issues, but again, whoever said there was nothing wrong with it? Creaks galore, bearings wearing out in 5 minutes, etc., etc.
Nothing to do with weight and everything to do with proper functionality.
BSA doesn't have two problems. People wanting to run silly oversized spindles may have problems, but seeing as how the number one brand (Shimano) doesn't, it's not a problem for me and us purists who recognize a superior product.
