Originally Posted by queerpunk
fyi, they're called self extracting crankbolts. you tigten them, and it pulls the crank on to the square tapered bottom bracket spindle. when you loosen, it pulls them off. for other types of cranks, you need a crank puller, which threads on to the crank, and then threads on to itself to push the cranks off the spindle.
self extracting crankbolts are the cool.
the concept is pretty cool. i snapped the one that came on my sl track cranks though, and was worried that i'd completely screwed up the cranks. turns out they're just little inserts that screw into the cranks and they can be removed with a chainring bolt tool.