The pros and cons of crank self-extractors
I have them on my Ultegra equipped nine speed bike and love them. They are especially nice when cleaning up the bottom bracket and crank/chainrings. Just a couple of quick turns with an allen key and off the the crank arm comes and goes directly into the cleaner. I wipe down the bottom bracket area and reattach the crank arm and it's ready to go. Easy peasy, takes maybe ten minutes if that.