Originally Posted by
Rogerogeroge
The dust caps were an ingenious thing that extracted the cranks. If you're buying a crank, make sure those dust caps, and especially the threads are in good shape.
Self-extracting crank bolts far proceeded Octalink cranks and were provided on several square taper cranks and sold as an aftermarket part. Also, only Ultegra and Dura Ace Octalink cranks had self-extracting bolts. 105 Octalink cranks had standard fixing bolts and required a crank puller.
I agree with Andy on the reduced service life of the Octalink bottom brackets and their cousin, the ISIS bottom bracket standard.
While both Octalink and ISIS bottom brackets shared the necessity for smaller bearings, don't confuse the two designs. Shimano's Octalink bottom brackets were well made and generally had a good service life. I had them on two bikes and they lasted tens of thousands of miles and were still in good working order when replaced for other reasons. ISIS was designed to get around Shimano's Octalink patent and was made public domain. Therefore, ISIS bottom bracket were made by numerous manufactures in a wide variety of quality levels, mostly poor and subject to early failure. It's those ISIS bottom brackets that gave the whole concept its bad name.
That said, it was indeed external bottom brackets with their inherently larger bearings and somewhat reduced weight that made Octalink/ISIS obsolete.