Originally Posted by
davidad
There was never anything wrong with the old square taper BB spindle. Everything that followed is just new and improved. If shimano's octalink was that good they wouldn't have replaced it as soon as they did.
I think the main problem with ISIS and octalink was that the axle diameter caused the bearings to shrink, which caused them to wear out quicker.
The new shimano external BB system is good. I like it, despite some of it's shortcomings.
For one, the expensive drive side doesn't wear out each time you go to remove it, only the cheap left side does. You don't have to worry about stripped extraction threads. On the downside, you can't adjust the chainline too much and it's quite specific about having a properly faced BB shell.