Originally Posted by FBinNY

Ti spindles disappeared for two reasons. The first is an unacceptably higher failure rate that pretty much said they were unfit for general consumption. The second was the advent of external bearings and large iameter spindles which pretty much eliminated the weight advantage.

Ti bars are gone because CF is both lighter and cheaper, so it's aluminum for rough service or low price, and CF for high end with no place for Ti in the mix. Same applies, but to a lesser extent with Ti seatposts.

Aluminum steerers died because of unacceptably high risk of catastrophic failure. Once CF proved itself it was CF for weight, Steel for durability.

Steel BB RD pulleys are gone, because once quality engineering plastic were available there was absoluteley no reason for steel or aluminum pulleys.

Stuff changes because new materials and manufacturing techniques takes away the raison d'etre. Also consider that we live in a litigious age and than heavier riders are riding bicycles very similar or even identical to race equipment. That means that we can't build for 160# riders and have to maintain high service life standards for all critical components. (or have max rider weight disclaimers which people are going to fudge or ignore anyway.